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Solar radiation enters the Earth's atmosphere with a portion being scattered by clouds and aerosols.

Processing, archiving and distributing Earth science data
at the NASA Langley Research Center

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Frequently Asked Questions and Information

Frequently Asked Questions

The General Questions, Questions related to ordering data, and Troubleshooting Information are not project specific, but are related to the web site as a whole. The Project Information section currently contains specific questions and information for CERES, MISR, TES, SSE, and ERBE. Other project information will be added.

The availability of new data sets is dependent upon a number of factors, many of which are not under our direct control. This makes it difficult to give exact release dates for specific data sets. However, we would be happy to notify you when the item you desire does become available for distribution.

Please visit the Science Directorate Educational Resources page for information on videos, classroom projects, and activities that are available for all grade levels. Trading cards, book marks, and lesson plans can also be downloaded from this site.

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The Order Data page provides information for accessing the ordering systems available for the Langley Data Center data.

Please refer to our Projects Supported page for additional documentation concerning the projects we support. Each project has a page with links to documentation.

Read software can be requested at the time an order is placed, or downloaded separately. To download the software without placing an order, access the read software from the appropriate project link on the Projects Supported page.

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If you experience problems accessing Reverb, or have difficulty ordering data from the tool, please contact User Services for assistance. If you receive an error message, write it down and include the error message in your communication with User Services.

Please take the time to read the order tool help pages or the Reverb Tutorial which have instructions on using the system, as well as explanations of the screens and menu choices. If you are still experiencing problems with the ordering system, contact User Services for assistance.

For most of the data we archive, we also provide read software. If you were unable to receive the read software with your order, select the project name on the Projects Supported page. You will be taken to the appropriate project table, where you can download the read software.

 

If you have tried using the read software and are still experiencing problems, please have the following information ready when you
contact User Services to allow us to assist you more effectively:

 

Computer Architecture/Operating System Information:

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Viewers:

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If you need to change the media type for your order, please contact User Services.

The Clouds and the Earth's Radiant Energy System (CERES) experiment provides radiometric measurements of the Earth's atmosphere from three broadband channels and is a follow-on to the Earth Radiation Budget Experiment (ERBE) mission. CERES products include both solar-reflected and Earth-emitted radiation from the top of the atmosphere to the Earth's surface. The CERES experiment will lead to a better understanding of the role of clouds and the energy cycle in global climate change.

Instruments Launch Dates
PFM November 27, 1997 as part of the Tropical Rainfall Measuring Mission (TRMM) and was the first CERES instrument.
FM1 & FM2 December 18, 1999 into polar orbit on board the EOS flagship Terra.
FM3 & FM4 May 4, 2002 on board EOS Aqua.
FM5 October 28, 2011 on board Suomi National Polar-orbiting Partnership (NPP) satellite.
  Access CERES Instrument specifications and Operation scan modes by month.

 

Top-of-the-Atmosphere (TOA) is a surface approximately 20 km above the Earth's surface.
The TOA is an ellipsoid x²/a² + y²/a² + z²/b² = 1
where a = 6408.1370 km and b = 6386.6517 km.

Flux - is an energy flow through a unit area over a unit time; hence the units of W m-2. As radiation interacts with matter at all atmospheric layers and surfaces, measuring, understanding, and modeling the spatial, temporal and spectral distribution of fluxes is important. Flux characterizes our climate and is represented as Up, Down, Net, TOA & Surface.

Given the vertical layered structure of Earth atmosphere above underlying surfaces, the vertical variability of these fluxes is of particular interest. Hence the term "Up" and "Down" for characterizing the direction of flow of radiative fluxes at a particular level. Moreover, by counting in or out these "Up" and "Down" energy fluxes, one can define a "Net" flux that is ultimately responsible for the net energy loss or gain within any two such layers. This concept is important in defining the radiative heating or cooling of each atmospheric/surface element.

The-Top-of-Atmosphere (TOA) layers are where the first interaction occurs as the radiation from the Sun reaches Earth and then the various atmospheric layers containing gases, clouds, aerosols, and/or other constituents before finally reaching the Surface. Solar radiation is scattered and/or absorbed in each of these material layers while the atmospheric and surface constituents emit their own share of radiation. Shortwave (SW) and Longwave (LW) are the two primary spectral parts the energetics can be split into and may be further divided into finer spectral intervals depending on the specifics of the physical processes under investigation.

Total 0.3 - 100.0 microns
Shortwave 0.3 - 5.0 microns
Longwave 8.0 - 12.0 microns

 

Aqua has a 1:30 PM equator crossing time.
Terra has a 10:30 AM equator crossing time.

The CERES Field of View (FOV) is synonymous with the term Footprint and is determined by the Point Spread Function (PSF) which is a two-dimensional, bell-shaped function that defines the CERES instrument response to the viewed radiation field. The resolution of the CERES radiometers is usually referenced to the optical FOV which is 1.3° in the along-track direction and 2.6° in the cross-track direction. The CERES FOV or footprint size is referenced to an oval area that represents approximately 95% of the PSF response. Since the PSF is defined in angular space at the instrument, the CERES FOV is a constant in angular space, but grows in surface area from a minimum at nadir to a larger area at shallow viewing angles.

All-Sky scene, also known as total, is determined from all CERES footprints (20 km nominal resolution) within the given temporal or spatial domain.

Clear-Sky scene has different algorithms depending on the product ERBE-like, Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF), or Energy Balanced and Filled (EBAF). ERBE-like clear-sky scene is determined from CERES footprints that were crudely identified as clear using the ERBE scene id algorithm which uses climatological, zonal LW thresholds and appropriate SW thresholds based on 12 scene ids.

EBAF & SSF clear-sky scenes are determined from CERES footprints that are 99% clear as identified by CERES-MODIS clear-sky mask from the MODIS pixels contained within the CERES footprint. SSF clear-sky products contain many cloudy regions that may have no clear-sky observations for one particular month with no attempts to fill these regions. The EBAF clear-sky products filled all non-observed clear-sky regional fluxes for a complete clear-sky global map, and all temporal and spatial domains should have clear-sky fluxes.

The NPP platform carries the FM5 instrument, which operates in the fixed azimuth scanning mode though it can operate in a rotating azimuth scanning mode. The Terra and Aqua satellites carry two CERES instruments onboard, one in Cross-Track mode and the other in Rotating Azimuth Plane Scan (RAPS) mode or in Fixed Azimuth Plane Scan (FAPS) mode. The first CERES instrument PFM, launched in November 1997 as part of the TRMM mission, was powered off May 29, 2001.

Fixed Azimuth Plane Scanning (FAPS) has scan lines perpendicular to the path of the satellite, while Rotating Azimuth Plane Scan (RAPS) lines are at a wide range of angles with respect to the satellite's path. An instrument operating in RAPS has increased spectral darkening of the transmissive optics. The Cross-Track instrument is recommended by CERES, since the spatial distribution of footprints is uniform.

CERES is a global data set whose satellite orbit determines the spatial coverage at the surface.
 

Satellites Instruments MinLat MaxLat MinLon MaxLon Spatial Altitude Temporal Range
NPP FM5 -90 90 -180 180 824 km Feb 2012 - present
Aqua FM3 & FM4 -90 90 -180 180 705 km Jun 2002 - present
Terra FM1 & FM2 -90 90 -180 180 705 km Feb 2000 - present
TRMM PFM -40 40 -180 180 350 km Dec 1997 - Sep 1, 1998
*occasional coverage for coincident overflights with Terra in 1999 - 2001

 

1 byte integer 127
2 byte integer 32767
4 byte integer 2147483647
4 byte real 3.402823E+38
8 byte real 1.7976931E+38
Surf Index CERES Surface Type
1 Evergreen Needle Forest
2 Evergreen Broadleaf Forest
3 Deciduous Needle Forest
4 Deciduous Broadleaf Forest
5 Mixed Forest
6 Closed Shrubs
7 Open Shrubs
8 Woody Savannas
9 Savannas
10 Grassland
11 Wetlands
12 Crops
13 Urban
14 Crop/Mosaic
15 Permanent Snow/Ice
16 Barren Desert
17 Water
18 Tundra
19 Land Snow
20 Sea Ice

 

Access the full parameter list and temporal coverage of available data sets by selecting each individual product on the CERES Data and Information page..
 

Products Select Parameters
BDS Filtered Radiances, Detector Values, Instr. Engineering Parameters
CERES-NEWS-CCCM TOA Flux, Surface (Radiative) Flux, OLR, Surface Types, Aerosol Optical Thickness, Cloud Base Height, Cloud Top Height, Cloud Optical Depth, Aerosol Extinction Coefficient, Aerosol Base Height, Aerosol Top Height, Cloud Extinction Coefficient, Cloud Vertical Profile, Radar-only Liquid Water Content, Radar-only Liquid Ice Content, Vertical Flux Profile, Unfiltered Radiances, Filtered Radiances.
CRS Cloud Properties, TOA Fluxes, Surface (Radiative) Fluxes, Unfiltered Radiances, Surface Types
EBAF Clear-sky and All-sky TOA Adjusted Fluxes
ES-4 Clear-sky and Total-sky Fluxes, Clear-sky and Total-sky Solar Incidence, Clear-sky and Total-sky Albedo
ES-8 TOA Fluxes, Unfiltered Radiances, Filtered Radiances, OLR, ERBE Scene Identification
ES-9 Clear-sky and Total-sky Fluxes, Clear-sky and Total-sky Solar Incidence, Clear-sky and Total-sky Albedo
FSW Clear-sky and All-sky TOA Fluxes, Surface (Radiative) Fluxes, OLR, Clear-sky and All-sky Albedo, Cloud Properties, Surface Types
ISCCP-D2like Cloud fraction, Effective Pressure, Temperature, optical depth, IWP/LWP, particle size, IR Emissivity in PC/Tau bins similar to ISCCP-D2 product
SFC Clear-sky and All-sky TOA Fluxes, Surface (Radiative) Fluxes, OLR, Clear-sky and All-sky Albedo, Cloud Properties, Surface Types
SRBAVG Clear-sky and All-sky TOA Fluxes, Surface (Radiative) Fluxes, OLR, Clear-sky and All-sky Albedo, Cloud Properties, Surface Types
SSF Cloud Properties, TOA Fluxes, Surface (Radiative) Fluxes, Unfiltered Radiances, Filtered Radiances, OLR, Surface Types
SSF1deg Cloud Properties, TOA Fluxes, Surface (Radiative) Fluxes
SYN1deg Cloud Properties, TOA Fluxes, Atmosphere Fluxes, Surface (Radiative) Fluxes, Aerosols
SYN/AVG/ZAVG Clear-sky and All-sky TOA Fluxes, Surface (Radiative) Fluxes, OLR, Clear-sky and All-sky Albedo, Cloud Properties, Surface Types, Radiative Flux Profiles

 

  • Clouds and Computed Flux Profile Data Sets represent surface, within-atmosphere, and Top-of-Atmosphere (TOA) fluxes from radiative transfer model calculations with inputs from several sources.
  • Clouds and TOA/SFC Flux Data Set represents TOA and surface radiation derived from CERES and imager measurements.
  • ERBE-like Data Sets are consistent with earlier ERBE processing.
  • CERES-NEWS-CCCM data sets integrate measurements from CERES, MODIS, CALIPSO, and CloudSat.
  • CERES-MISR-MODIS (SSF-SSFM) data sets integrate measurements from CERES, MISR, and MODIS.
  • Instrument data (BDS) represent Instrument Data.
  • SSF/SYN1deg-lite Data Sets represent Single Scanner Satellite Footprint (SSF), Synoptic Radiative Fluxes (SYN), clouds, TOA and surface fluxes with improved CERES instrument Edition 3 (2010) calibration, processed with Edition 2 algorithms.
Level Processing Products
Level 1B Data products are processed to sensor units. The BDS product contains CERES footprint filtered broadband radiances, geolocation and viewing geometry, Sun geometry, satellite position and velocity, and all raw engineering and status data from the instrument. BDS
Level 2 Data products are derived geophysical variables at the CERES footprint resolution as the Level 1B source data. They include the Level 1B parameters, along with the retrieved or computed geophysical variables such as radiative broadband fluxes and their associated MODIS cloud properties. CRS, ES-8, SSF
Level 3 Data products are the radiative fluxes and cloud properties that are spatially averaged into uniform regional and zonal grids and globally and also temporally averaged into daily, monthly hourly, or monthly means. AVG, ZAVG, ES-4, ES-9, FSW, ISCCP-D2like, SFC, SRBAVG, SYN, SSF/SYN1deg-lite
Level 3B/4 Level 3 data products that are adjusted within their range of uncertainty so as to satisfy known constraints on the climate system (e.g., consistency between average global net TOA flux imbalance and ocean heat storage). EBAF

 

Subsetting allows users to create smaller files (subsets) of the original data by selecting desired parameters, parameter criterion, or latitude and longitude coordinates.

Order CERES Level 3 Edition 2.5 "lite" subset data from the CERES Level 3 Ordering Page.

CERES file names are formed using the dataset name, configuration code and date information which make each file name unique.

A Dataset name consists of CER_<ProductID>_<Sampling-Strategy>_<Production-Strategy>
Eg. CER_SSF_Terra-FM1-MODIS_Edition2B

The SSF Filename consists of the <Dataset name> combined with the <Configuration Code> and <Date> to make it unique
Eg. CER_SSF_Terra-FM1-MODIS_Edition2B_120145.2001052812

<ProductID> Identification value - CRS, ES8, SSF, SYN
<Sampling-Strategy> Satellite, instrument, and imager - TRMM-PFM-VIRS, Terra-FM1-MODIS, Aqua-FM3-MODIS
<Production-Strategy> Edition or campaign - At-launch, Edition2, ValidationR1
<Config-Code> 6-digit file and software version management code number - 120145
<Date> Date in the form YYYYMMDDHH - 200105812 (May 28, 2001 GMT hr12)

The CERES Processing Levels page shows the levels of processing and the resulting products. See CERES Data and Information for additional information such as spatial and temporal coverage, file size and frequency, and data sets available for ordering.

Products Usage Suggestions
CRS Consistent flux and cloud properties.
EBAF Best estimate (net-balanced) TOA fluxes. Evaluation of climate model and energy budget.
ERBE-like Compares original ERBE(1985 - 1989) fluxes with CERES. No CERES algorithm improvements.
FLASHFLUX Quicklook near real-time.
ISCCP-D2like Monthly cloud properties in a similar format to ISCCP.
SSF Instantaneous footprint radiances, fluxes and MODIS clouds.
TOA fluxes and clouds to compare with A-train (Aqua) products.
TOA fluxes for long term climate trend evaluation, use SSF with associated cloud and aerosol properties.
SSF/SYN1deg-lite 10 year dataset (2000 - 2010) with an abbreviated parameter list and the latest CERES instrument calibration.
SYN Best estimate surface fluxes.
Instantaneous footprint level.

 

Visualize CERES data with view_hdf:

  • view_hdf a visualization and analysis tool for accessing data stored in Hierarchical Data Format (HDF) and HDF-EOS.

NetCDF is a set of software libraries and machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data.

Subsetting is available via the CERES Order Tool.

Earth Radiation Budget Experiment (ERBE) is a NASA satellite measurement project that came about in the late 1970's as a result of NASA recognizing the importance of improving our understanding of the radiation budget and its effects on the Earth's climate, and a need to make accurate regional and global measurements of the components of the radiation budget. ERBE observations were collected from three satellites that measured global albedo, outgoing and reflected fluxes, and solar incidence. The first full calendar month of ERBE observation began on November 1984. The ERBE project officially ended after the decommission of the NASA ERBS satellite mission on August 2005. All ERBE data are permanently archived at the NASA Langley Atmospheric Science Data Center.

The three satellites ERBS, NOAA-9, NOAA-10 carrying two ERBE instrument packages (Scanner and NonScanner) were used. The NASA Goddard Space Flight Center built the Earth Radiation Budget Satellite (ERBS) on which the first ERBE instruments were launched by the Space Shuttle Challenger in 1984. ERBE instruments were also launched on two operational National Oceanic and Atmospheric Administration (NOAA) weather monitoring satellites, NOAA-9 and NOAA-10 in 1984 and 1986, respectively.

Earth Radiation Budget Satellite (ERBS) is a dedicated NASA research satellite launched by Space Shuttle Challenger in October 1984 and was the first spacecraft to carry ERBE instruments into orbit. ERBS is in a precessing orbit (57 degree) allowing the ERBE instruments on board this satellite to provide complete diurnal sampling in 72 days. The ERBS satellite mission came to an official end on August 2005 after 20+ years of continuous operations.

The Radiation Budget represents the balance between incoming energy from the Sun and outgoing thermal (longwave) and reflected (shortwave) energy from the Earth.

Global spatial coverage is provided by the ERBE instruments on board the NOAA-9 and NOAA-10 satellites. Coverage between 60 degrees north and south latitude is provided by ERBS satellite. ERBS is a precessing satellite and produces the best diurnally sampled data because it sees all 24 hours of local time in 72 days. NOAA-9 and NOAA-10 are sun-syn satellite and do not cover the entire diurnal cycle, however they see the entire globe. NOAA-9 is the afternoon (2:30 PM LST) satellite and NOAA-10 is the morning (7:30 AM LST) satellite.

The ERBE/ERBS instruments operated from November 1984 to August 2005. The ERBE/NOAA 9 instruments operated from February 1985 to November 1992. The ERBE/NOAA 10 instruments operated from January 1986 to November 1992. ERBE data availability depends on both instrument type and satellite.

These are two types of instruments specifically designed by a team of electronic, thermal, and mechanical experts, built and integrated with the ERBS and NOAA satellite platforms by TRW of Redondo Beach, CA.

Scanner
A set of three co-planar detectors (longwave, shortwave and total energy), all of which scan from one limb of the Earth to the other, across the satellite track (in its normal operational mode).

The scanner instrument has a smaller footprint (40 km at nadir) and scanned across the orbit plane to provide maximum spatial coverage. The scanner measures directional radiance, not hemispheric flux. The directional radiance is converted to hemispheric flux using empirical statistical model (ERBE ADM). The scanner is designed for regional to large scale analysis, and due to the smaller footprint, the scanner product is able to separate clear sky data from all-sky data to provide both clear-sky and all-sky estimates.

NonScanner
A set of five detectors; one which measures the total energy from the Sun, two which measure the shortwave and total energy from the entire Earth disk, and two of which measure the shortwave and total energy from a medium resolution area beneath the satellite.

The Nonscanner instrument did not scan and pointed straight down to measure hemispheric flux from the Earth. The large footprint (1000 km) is designed only for large scale analysis, thus products provide only all-sky data. Because the nonscanner had less moving parts, it lasted a lot longer than the scanner instrument.

  • Total Channel: 0.2 to 50 microns
  • Shortwave Channel: 0.2 to 5 microns
  • Longwave Channel: 5 to 50 microns
  • Albedo - The ratio of reflective shortwave flux to the solar incoming flux at top of atmosphere (TOA), where zero (0.0) represents total absorption, and one (1.0) represents total reflectance.
  • Net - Net Radiation (Net) is the amount of total radiative flux energy deposited into the Earth system at top of the atmosphere (TOA).
  • OLR - Outgoing Longwave Radiation (OLR) is an alias for longwave (LW) radiative flux energy leaving the Earth system at top of the atmosphere (TOA).
  • RSR - Reflected Shortwave Radiation (RSR) is an alias for shortwave (SW) radiative flux energy leaving the Earth system at top of the atmosphere (TOA).
  • Scene Identification - The twelve possible ERBE scene categories constructed from combinations of geography and cloud cover resulting in distinct Angular Distribution Models.
  • Solar Incidence - The time integrated value of solar incoming flux into the Earth system at top of the atmosphere (TOA).
  • Total Solar Irradiance - The average power received on a unit area at the mean Earth/Sun distance (Watts/square meter).

ERBE net radiation is defined at top of the atmosphere (TOA) as the following:
Net (TOA) = Solar_down (TOA) - SW_up (TOA) - LW_up (TOA)

where Solar_down (TOA) is the solar incoming flux at TOA, SW_up (TOA) is the reflected shortwave flux at TOA, and LW_up (TOA) is outgoing longwave flux at TOA. The sign convention for ERBE net radiation is that positive/negative sign represents a net radiative energy surplus/deficit of the Earth system, respectively.

Cloud radiative forcing (CRF) is not an ERBE parameter. However, it can be calculated from the ERBE scanner data set using the all-sky and the clear-sky parameters as the following:

Cloud Radiative Forcing = Clear-sky Flux - All-sky Flux

Cloud radiative forcing can not be calculated from the ERBE nonscanner data set due to the lack of clear-sky parameters.

ERBE data are available in many different resolutions; ranging from instantaneous satellite footprint data (40km spatial scale), to monthly mean regional averaged gridded data (2.5-degree, 5-degree, and 10-degree grid), to global-monthly mean data. In addition, daily mean regional averages and monthly-hourly regional averages are also available.

  • ERBE uses a regular equal-angle grid system. The ERBE regional gridded data is available in three different resolutions (2.5-degree, 5-degree, and 10-degree) depending on the instrument type.
  • For the ERBE 2.5-degree regional data set, the ERBE grid contains 10,368 2.5-degree regions. This maps to 72 latitude zones with 144 regions in each (72 * 144 = 10368). The first ERBE 2.5 degree region is located at the North Pole - Greenwich meridian. The center location of region 1 is at 88.75N and 1.25E. The 2.5 degree grid extends eastward, one 2.5 degree region at a time, around the entire 2.5-degree latitude circle and then step southward, one 2.5-degree latitude zone at a time, until it reaches region 10368, which is centered at 88.75S and 358.75E.
  • For the ERBE 5-degree regional data set, the ERBE grid contains 2592 5-degree regions. This maps to 36 latitude zones with 72 regions in each (36 * 72 = 2592). The first ERBE 5-degree region is located at the North Pole - Greenwich meridian. The center location of region 1 is at 87.5N and 2.5E. The 5-degree grid extends eastward, one 5-degree region at a time, around the entire 5-degree latitude circle and then step southward, one 5-degree latitude zone at a time, until it reaches region 2592, which is centered at 87.5S and 357.5E.
  • For the ERBE 10-degree regional data set, the ERBE grid contains 648 10-degree regions. This maps to 18 latitude zones with 36 regions in each (18 * 36 = 648). The first ERBE 10-degree region is located at the North Pole - Greenwich meridian. The center location of region 1 is at 85N and 5E. The 10-degree grid extends eastward, one 10-degree region at a time, around the entire 10-degree latitude circle and then step southward, one 10-degree latitude zone at a time, until it reaches region 648, which is centered at 85S and 355E.

The ERBE region number can be easily determined with the following:

2.5-degree Data: Region number = int(colat / 2.5) * 144 + (lon / 2.5)

5-degree Data: Region number = int(colat / 5) * 72 + (lon / 5)

10-degree Data: Region number = int(colat / 10) * 36 + (lon / 10)

where colat = 90 - latitude

For users working with regional data needing global averages, area weighting needs to be applied to the regional averages because of the equal-angle grids. Global data are also available in the S4 data sets.

Compilation successful but values read seem off:
Check to see what bit machine you're running on. If it is a 64-bit machine, check to see if the is a 32-bit compile option available. Other issues affecting compilation would be differing versions of the operating system and compilers the read software are being run on.

Big Endian Little Endian:
Unix machines are Big Endian architecture while Linux systems are Little Endian architecture. Data generated on a Unix machine are byte swapped on the Linux machine when data files are transferred.

Zipped files:
Any zip files need to be unzipped before use. Most programs only read one file at a time.
Example:
filename: s9_8502_5.zip
unzip s9_8502_5.zip

Some limited ERBE datasets are available in ASCII format, such as the ERBE CD-ROM data (scanner only) and ERBE/ERBS Nonscanner Edition3_Rev1 data. More information is in the Data Access Questions section.

Please submit your science questions directly to the NASA Langley Atmospheric Science Data Center's (ASDC's) User Services. They will forward them to the volunteer scientists assigned to the ERBE data sets. Since the ERBE project has officially ended, the science support is very limited and depends on the availability of our volunteer scientists. It may take a few days to receive your answers.

  • Level 1: NonScanner data: TSI
  • Level 2: Instantaneous unfiltered satellite footprint data: S-7, S-8
  • Level 3: Monthly Averaged gridded data: S-4, S-4N, S-4G, S-4GN, S-9, S-10, S-10N
S-4 Regional, Zonal, and Global Averages
S-4N NonScanner Regional, Zonal, and Global Averages
S-4G Regional, Zonal, and Global Averages
S-4GN NonScanner Regional, Zonal, and Global Averages
S-9 Scanner Earth Radiant Flux and Albedo
S-10 NonScanner Earth Radiant Flux and Albedo
S-10N NonScanner Earth Radiant Flux and Albedo
S-7 NonScanner Medium-Wide FOV Data Tape
S-8 Processed Archive Tape
TSI Total Solar Irradiance

 

The data are available in both native format (NAT), and Hierarchical Data Format (HDF) as listed and described in the Earth Radiation Budget Experiment (ERBE) Langley ASDC Project Document. The following provide a quick summary of the available data.
 

  Scanner and Nonscanner
(Scanner-dependent)
Original Nonscanner
(Scanner-independent)
Newer Nonscanner
(Scanner-independent)
Total Solor Irradiance
Temporal Coverage 11/1984 - 02/1990: 11/1984 - 11/1995: 11/1984 - 09/1999: 10/1984 - 03/2003:
Data Sets
  • ERBE_S4/S7/S9_NAT
  • ERBE_S4G_/SC/MFOV/WFOV
  • ERBE_S10_MFOV/WFOV
  • ERBE_S4N_NAT
  • ERBE_S4GN_WFOV
  • ERBE_S10N_WFV
  • ERBE_S10N_WFOV
  • Edition2 & Edition3 products
  • ERBE_S7_NAT
  • ERBE_TSI_ERBS_NAT

 

There are single satellite and combined-satellite scanner products. The best source for these data is to order the ERBE scanner CD which gives all the S4G monthly mean 2.5 degree gridded data from both single satellite and combined-satellite product in ASCII format. Also, ordering the S4G HDF data online and using the ncdump utility to perform a straight ASCII dump is another option. NOAA-9 and NOAA-10 provide global coverage at different local sampling times. These do not provide the full diurnal coverage, which can affect the quality of the shortwave and longwave estimate. ERBS covers all 24-hour local time, but only for regions between 60N and 60S.

Scanner and Nonscanner instruments are processed independently using separated instrument calibration procedure and data processing algorithm. Because of these differences, it is best to work with these two data sets separately.

  • ERBE/ERBS scanner operated for ~5 years: November 1984 - February 1990
  • ERBE/NOAA-9 scanner operated for ~2 years: February 1985 - January 1987
  • ERBE/NOAA-10 scanner operated for ~2 years: January 1987 - April 1989

Even though NOAA-9 and NOAA-10 continued to fly mid to late 1990's, the ERBE Nonscanner record stopped due to instrument failure. Currently only the ERBE/ERBS noncanner data have been reprocessed to correct for satellite altitude drift and other instrument related issues. These new data are only released as the ERBE/ERBS S10N Edition3 product. More information is available in the Edition3 Data Quality Summary, including a special website to obtain user-applied corrected and ASCII formatted data. No S4GN data is available for this latest data. NOAA-9 and NOAA-10 data have not been reprocessed to correct for the satellite altitude drift issue with no plans for a future fix. The satellite altitude drift only affects the Noncanner data set. The scanner data set is not affected by this issue.

Scanner and Nonscanner instruments are processed independently using separated instrument calibration procedure and data processing algorithm. Because of these differences, it is best to work with these two data sets separately.

ERBE/ERBS Nonscanner operated for ~20 years November 1984 - August     2005
ERBE/ERBS S10N Ed3 Nonscanner operated for ~14 years January     1985 - September 1999
ERBE/NOAA-9 Nonscanner operated for ~8 years February    1985 - November 1992
ERBE/NOAA-10 Nonscanner operated for ~8 years February    1985 - November 1992

** Note** : ERBE/ERBS nonscanner TOA flux data from October 1999 to August 2005 is unavailable to the public due to unresolved instrument anomaly issues.

NFOV narrow field-of-view   2.5 degree resolution
MFOV-NF medium field-of-view numerical filter 5.0 degree resolution
WFOV-NF wide field-of-view numerical filter 5.0 degree resolution
MFOV-SF medium field-of-view shape factor 10.0 degree resolution
WFOV-SF wide field-of-view shape factor 10.0 degree resolution

Sample Filename: s4gn_wnf5._yymm_s
"yy" represents the year (e.g., 89 - 1989);
"mm" represents the number value of a month (e.g., 01 = January, 12 = December)
"s" represents the satellite code:
1 = NOAA-9
2 = ERBS
3 = NOAA-10
4 = NOAA-9/NOAA-10
5 = ERBS/NOAA-9
6 = ERBS/NOAA-10
7 = NOAA-9/ERBS/NOAA-10

  • Telemetry - Process data from NOAA and GSFC to a common format, interpret the instrument and spacecraft housekeeping data, and analyze instrument commands and in-orbit environment.
  • Ephemeris - Analyze orbit position data from GSFC for each of the three satellite platforms.
  • Merge/Count Conversion - Combine telemetry and ephemeris data to produce Earth location geometry and convert radiometric counts produced by the instruments into satellite-altitude radiances.
  • Inversion - Identify the scene viewed by the instruments and interpret the measurements at the top of the Earth's atmosphere using shape factor and numerical filter inversion techniques.
  • Daily and Monthly Time/Space Averaging - Convert from time-ordered to regionally-accessible data sets and apply diurnal models to estimate hourly, daily, and monthly averages of radiation budget components.
  • Data Products - Generate well-documented science archival products in an easily accessible format.

The ERBE data product documentations can be found at the links below:

Visualize ERBE data with view_hdf:

  • view_hdf a visualization and analysis tool for accessing data stored in Hierarchical Data Format (HDF) and HDF-EOS.

Visualize ERBE data with HDFView:

Short QuickTime movies of ERBE data can be found at the links below:

See the MISR web site, and also Diner, D. J. et al. "Performance of the MISR Instrument During Its First 20 Months in Earth Orbit", IEEE. Trans. Geosci. Rem. Sens. 40 (7), 1449-1466 (July 2002).
 

MISR Instrument Description
Parameter Value Characteristics
Camera View Zenith Angles at Earth's Surface 0.0 ° (nadir), 26.1, 45.6, 60.0 and 70.5 ° (both fore and aft of nadir)

MISR characteristics.

Global Mode:

  • 275m sampling in all nadir bands
  • 275m sampling in red band of off-nadir cameras
  • 1.1km for other channels

Local Mode (targeted):

  • 275m all channels all cameras
Swath Width 360 kilometers (224 miles) (9-day global coverage)
Cross-Track x Along-Track Pixel Sampling 275 x 275 meters (902 x 902 feet)
550 x 550 meters (0.34 x 0.34 mile)
1.1 x 1.1 kilometers (0.68 x 0.68 mile)
275 meters x 1.1 kilometers (0.17 x 0.68 mile)
Spectral Bands (Solar Spectrum Weighted) 446.4, 557.5, 671.7, 866.4 nanometers
Spectral Bandwidths 41.9, 28.6, 21.9, 39.7 nanometers

 

Measuring the reflectance of a target from different directions is really useful because geophysical media (the atmosphere, including the clouds and aerosols, the ocean, and terrestrial surfaces such as soil, vegetation and snow or ice) reflect solar light differently in different directions. In fact, the variations between the reflectances acquired from a variety of observation angles can be interpreted (with appropriate models) to document the properties of the target, just as the more familiar spectral differences are exploited to document its chemical composition.

Most imaging space-borne instruments acquire measurements for each location on Earth from a single direction at a time, usually within the limited range of (across-track) observation zenith angles allowed by the scanner or push-broom design of the sensor. The accumulation of multiangular observations with such instruments necessitates revisiting the site over rather long periods of time, from multiple days to a few weeks or more. By incorporating nine separate cameras oriented at various angles along the track of the platform, the MISR instrument is capable of acquiring multiple observations of the same site from a wide variety of zenith angles in a matter of a few minutes. This greatly facilitates the interpretation of the measurements and significantly improves the accuracy of the retrieved information.

Specifically, using its multi-angular and multi-spectral capability, the MISR instrument

  1. better distinguishes between objects and surfaces than would be possible on the basis of spectral variations alone;
  2. exhibits an enhanced sensitivity to aerosols and thin cirrus clouds, both of which are ubiquitous and usually hard to detect, especially at large observation zenith angles and/or over bright backgrounds;
  3. provides a three-dimensional (stereoscopic) view of clouds that allows users to estimate their height;
  4. makes it possible to use clouds as tracers of winds aloft due to the time lapse (about 7 minutes) between the most forward and the most backward views;
  5. yields at once measurements that accentuate or minimize the effect of sun glint over the ocean and other water surfaces, thereby enabling observations even when traditional sensors are hampered by the very high reflectance of these surfaces, and
  6. permits users to much more accurately estimate the hemispherical albedo of the target, which is thus calculated on the basis of nine different values instead of only one.

More detailed information is provided on the MISR web site Science Goals and Objectives page.

 
MISR employs nine discrete cameras pointed at fixed angles. MISR's cameras are named Df, Cf, Bf, Af, An, Aa, Ba, Ca, and, Da, beginning with the most forward-viewing oblique camera and ending with the most aft-viewing oblique camera. The initial letter (A, B, C, D) denotes the focal length of the camera lens, with the A cameras having the shortest focal length and the D cameras the longest. With the exception of the A design, which is used for the nadir view as well as the near-nadir views, each letter (B, C, D) also denotes the camera angle, that is, the zenith angle of the optical axis of the camera. The small letters (f, n, a) denote whether the camera is looking forward, nadir, or aftward. Nominally, the view angles for the off-nadir A, B, C, and D cameras are 26.1, 45.6, 60.0, and 70.5 degrees, respectively, relative to a local horizontal plane at mean sea level. There may be small variations with orbital position and location within the field of view. In the product file names, both letters of the camera name are capitalized. Arrangement of Cameras
MISR characteristics.

 

The instantaneous swath of any imaging instrument, including MISR, is the width of the region that is actually observed across the track of the instrument at any time during any particular overflight. The instantaneous swathes of the cameras on the MISR instrument vary from 376 to 414 km, but the instantaneous swath of the overlap of all cameras is 360 km. This means that whenever MISR passes exactly overhead of a site, its nine cameras also observe the neighborhood of that site, up to 180 km on either side of the projection of the track of the Terra platform on the Earth's surface. The swath also refers to the entire region being observed by MISR in the course of one particular orbit: in this case, it refers to an area that is about 20,000 km long and 360 km wide.

The Terra platform that carries MISR and other scientific instruments flies at an altitude of 705 km above sea level on a sun-synchronous orbit. It revolves once around the planet in 98.88 minutes and thus completes about 14.5 revolutions per day. In the context of MISR data exploitation, each complete revolution is called an orbit, and orbits are consecutively numbered from launch. The number of the orbit is thus directly related to the time span since launch.

In practice, since MISR is an optical sensor that measures the reflectance of the Earth in the solar spectral range, it is acquiring useful data only while the Terra platform is over the illuminated (day) side of the planet, i.e., during one half of the complete orbit or a bit less. Of course, the Earth itself keeps turning around its own axis while Terra proceeds on its orbit. As a result, when Terra completes an orbit and initiates the next one, it actually flies over quite different regions. The orbit number thus also indicates the areas of the planet observed. For these reasons, the orbit number is explicitly included in the name of many MISR data and product files.

The sun-synchronous orbit of Terra was selected in such a way that after 233 revolutions around the planet, or some 16 days, the platform returns to exactly the same locations and observes them under nominally identical angular conditions. Because of the 360 km instantaneous swath width of the MISR instrument, it is possible to gather multiple sets of observations (each with 9 cameras and 4 spectral bands) of a particular site in 2 days (Poles) to 9 days (Equator), depending on its latitude, but of course under a variety of angular conditions.

An Orbit/Date Conversion tool is available from the ASDC web site.

Since the orbits of the Terra platform repeat themselves every 233 revolutions around the Earth, it is natural to name each of these different trajectories or paths. For MISR, the path is the generic name (actually the numeric label) of all orbits that observe the same areas under the same nominal angular conditions. Areas that are close to each other in longitude will be covered by paths with similar numbers. The path number is also included in the file name of MISR products.

The path numbering system uses the Landsat Worldwide Reference System-2 (WRS-2). WRS-2 consists of 233 paths progressing systematically from east to west, and defined such that path 1 crosses the equator at 64.60° west longitude.

Orbital
Paths/Blocks
Orbital Paths/Blocks.

 

The generic data file for MISR is a swath, i.e., a set of measurements for the entire area observed during the day part of the orbit. This is a very large amount of data. To simplify the storing and processing of these data, swathes are broken into a series of predefined, uniformly-sized boxes along the ground track called blocks. Each path is divided into 180 blocks measuring 563.2 km (cross-track) x 140.8 km (along-track). For a given path, a numbered block always contains the same geographic locations. Hence, areas that are close to each other in latitude will belong to blocks with similar numbers. Because of seasonal variations in the portion of the Earth that is in daylight, only up to about 142 blocks will contain valid data at any particular time.

A MISR Browse Tool is available to help determine MISR paths and block numbers for specific geographic regions. An Orbit/Date Conversion Tool and a Lat/Lon to MISR Path/Block Tool are also available.

Paths/Blocks
Example
Browse Tool
Instructions
Example of MISR paths and blocks. MISR Broswe Tool; PowerPoint slides.

 

The MISR instrument continuously acquires data everywhere on Earth, but with a frequency that is dependent on the latitude of the location of interest. Indeed, due to the overlap of the swathes near the poles and their wide separations at the equator, repeat coverage varies from 2 to 9 days, respectively.

The nine MISR cameras acquire measurements every 275 m across track (250 m for the An camera). However, the data rate that would be required to transmit all the measurements from the nine cameras in the four spectral bands at that full resolution would exceed the capacity allocated to the MISR instrument on the Terra platform. To retain some of the high spatial resolution of the sensors without exceeding the data transfer quotas, MISR can be operated in two different data acquisition modes:

  1. In global (default) mode, a special averaging scheme is conducted on-board such that the data from all cameras other than An and all spectral bands other than red are averaged to 1.1 km before transmission to the receiving station. The spectral data (all 4 bands) from the An camera and the directional data in the red spectral band from all 9 cameras are therefore always available at the full spatial resolution.
  2. In local mode, it is possible to transmit all the data at the full resolution, but only for limited periods of time and therefore for limited regions, typically about 300 km in length (along track). Please refer to the MISR technical documentation for a detailed description of the various programming modes. Users may contact the ASDC User and Data Services office to request local mode observations.

Bands 1-4 are blue, green, red, and near-infrared, respectively. Variations in spectral response from one camera to another, for the same band, are minor and a standardized, downloadable spectral response curve in text format for each of the bands is available. Summary spectral response information (e.g., bandcenter, bandwidth) is also available in the Ancillary Radiometric Product ARP_INFLTCAL file, and the mathematical definitions of the product contents are provided in MISR Level 1 In-flight Radiometric Calibration and Characterization Algorithm Theoretical Basis Document (ATBD-MISR-02). A moments analysis is used to define the "in-band" spectral region. Because the filters are not perfect, there is a small amount of "out-of-band" light (less than 2% of the integrated energy), and the ARP_INFLTCAL file provides spectral response information for both the in-band region of each filter as well as for the total band.

Zenith angles are positive values measured from the local vertical at each point. Azimuth angles are measured clockwise from the direction of travel to local north. For both the Sun and cameras, azimuth describes the direction in which the photons are traveling. According to this convention the solar azimuth angle is therefore near 270 degrees when Terra is close to the equator, because of its morning equator crossing time. Additionally, the difference in view and solar azimuth angle will be near 0 degrees for forward scattered light, and near 180 degrees for backward scattered light. Sun and View angles are available in the MISR Geometric Parameters (MIB2GEOP) data product. Sun angles are also available in the L1B2 data files.

The Earth Science Data Type (ESDT) Version is used in the Reverb Search Tool (V001, V002, etc). The ESDT Version is incremented when a significant change to the product occurs.

The format Version is used to distinguish between software deliveries to ASDC that result in a product format change. The format version is given in the MISR data file name using the designator _Fnn_ where nn is the version number.

The product version is given in the MISR data file name using the designator _nnnn_ where nnnn is the product version number. Early on in the mission, several significant changes to ancillary datasets were required, and these changes triggered Product Version increments. At this point in time, most of the static ancillary data sets have stabilized and major changes to them are not predicted. Therefore, product version numbers are not necessarily incremented because of ancillary data set deliveries.

As MISR continues to reprocess the data products, Collections of scientifically consistent sets of data product versions become available. Collections may contain multiple format, production, and ESDT Versions.

An example of MISR's file naming convention is: MISR_AM1_GRP_TERRAIN_GM_Pxxx_Oxxxxxx_XX_Fnn_nnnn.hdf, where
MISR = Instrument Name
AM1 = Satellite Name
GRP_Terrain_GM = Georectified Radiance Product Terrain (Land Surface) Global Mode
Pxxx = Path Number
Oxxxxxx = Orbit Number
XX = Camera
Fnn = Format version of the product
nnnn = Product Version number

Individual MISR data set file naming conventions are found in the Project Guide.

Intensive assessment of MISR product data quality is an ongoing activity. Focused studies of some parameters are completed. Quality designators indicate the maturity of products and individual parameters. A product may contain parameters at varying quality levels. Below are the Maturity Level definitions:

Beta: Early release products for users to gain familiarity with data formats and parameters.
Provisional: Limited comparisons with independent sources have been made and obvious artifacts fixed.
Validated Stage 1: Uncertainties are estimated from independent measurements at selected locations and times.
Validated Stage 2: Uncertainties are estimated from more widely distributed independent measurements.
Validated Stage 3: Uncertainties are estimated from independent measurements representing global conditions.

  Calibration Co-registration

The current MISR Quality Statements and new MISR Quality Statements provide quality designators for the individual data products. Also, validation information is available from the MISR web site.

MISR calibration. Camera-to-camera co-registration.

 

MISR imagery can be obtained from Collections of MISR Imagery, which includes Browse images, and from MISR Supported Field Campaigns

There are three reasons that the ground coverage of two MISR images within the same path and block may differ.

  1. The position and pointing of the Terra satellite can vary by a small amount from orbit to orbit. For instance, the position is allowed to vary by no more than 20 km from one overpass to the next. If two images from the same camera for different overpasses are compared, a slight horizontal offset in image location can often be seen. This offset is usually the result of a shift in position of the satellite.
  2. The nine MISR camera footprints do not all cover the same exact extent on the ground. This variance occurs because the different camera views are acquired from devices which have different optical designs. In addition, the Earth rotates underneath the satellite in the time that elapses between acquisitions of a particular ground target by two different MISR cameras. Crosstrack boresight offsets are included in the MISR camera pointing angles to compensate, but this does not result in perfect overlap at every latitude. Therefore, two images from the same orbit but from different cameras almost never display precise overlap. A slight horizontal offset between any two camera images is usually visible.
  3. The MISR cameras are only commanded to acquire imagery over the sunlit portion of the Earth. Therefore a significant seasonal variation of the start block and stop block occurs for orbits within the same path. For example, some blocks acquired in Antarctica in December will not be acquired in June because they are dark during the later month.

The nadir camera Level 1 images have a swath width of about 376 km, compared to 414 km for the off-nadir cameras. The widths are different because the focal lengths of the MISR cameras change in relationship to the varying distance to the Earth for the different cameras. When viewing the same Earth area with a more oblique-pointing camera the focal length must be greater in order to preserve resolution. All of the camera images are 1504 pixels wide, and the focal lengths of the D, C, B, and off-nadir A cameras are chosen so that each pixel is 275 m wide. However, the nadir A camera uses the same focal length as the off-nadir A cameras, so each of its 1504 pixels is only 250 m wide. Another factor affecting overlap is Earth rotation during the time interval between when each camera acquires its image of a given area. The area of overlap among the cameras depends on latitude. Even though the forward and backward D camera (for example) have the same swath width, it is possible for the common area viewed by both to be less than 414 km.

SOM is a space-based map projection in which the reference meridian nominally follows the spacecraft ground track. It provides a mapping from latitude and longitude to a coordinate system that is approximately aligned with the MISR swath. SOM was used because it minimizes distortion and resampling effects, and permits the greatest flexibility in the choice of Earth-based projections. SOM also allows direct cross-comparison with data from other instruments and simplifies global mapping, since the data have already been geolocated. For more information see the MISR Level 1 Georectification and Registration Algorithm Theoretical Basis Document (ATBD-MISR-03), and also Snyder, J.P., Map Projection - A Working Manual, United States Geological Survey Professional Paper 1395, U.S. Government Printing Office, Washington, DC (1987).
 

  SOM vs Lat/Lon
Projection
Orbital
Paths/Blocks
Paths/Blocks
Example
  • Terra orbits Earth in a pattern of 233 unique paths.
  • SOM defines a separate projection for each path.
SOM Background. Orbital Paths/Blocks. Example of MISR paths and blocks.

 

MISR, the Multi-angle Imaging SpectroRadiometer instrument, was successfully launched into sun-synchronous polar orbit aboard Terra, NASA's first Earth Observing System (EOS) spacecraft, on December 18, 1999. MISR measurements are designed to improve our understanding of the Earth's environment and climate. Viewing the sunlit Earth simultaneously at nine widely-spaced angles, MISR provides radiometrically and geometrically calibrated images in four spectral bands at each of the angles.

MISR provides new types of information for scientists studying Earth's climate, such as the partitioning of energy and carbon between the land surface and the atmosphere, and the regional and global impacts of different types of atmospheric particles and clouds on climate. The change in reflection at different view angles affords the means to distinguish different types of atmospheric particles (aerosols), cloud forms, and land surface covers. Combined with stereoscopic techniques, this enables construction of 3-D models and estimation of the total amount of sunlight reflected by Earth's diverse environments.

MISR acquires systematic multi-angle imagery for global monitoring of top-of-atmosphere and surface albedos and to measure the shortwave radiative properties of aerosols, clouds, and surface scenes in order to characterize their impact on the Earth's climate.

For more details on the MISR instrument and project, see the MISR web site, the MISR Project Guide, and the MISR Experiment Overview. For details on MISR results, see the MISR publications page.

Illustrations of MISR instrument viewing the Earth:

MISR instrument:

This presentation from a Workshop on Exploring and Using MISR data visually shows the "How to" steps for obtaining and using MISR data:
"How to" obtain MISR information and data (PowerPoint).

MISR data products are grouped into three processing Levels. Level 1 processing provides corrected (or calibrated) instrument data. These data are processed and calibrated to remove many of the instrument effects. The resulting products thus contain minimal instrument or spacecraft artifacts and are most suitable for subsequent scientific derivations. Level 2 processing provides retrieval of derived scientific quantities, such as atmospheric aerosol and cloud measurements. Level 3 processing produces global grids of various parameter elements from the Level 2 products. These global grids are produced daily, monthly, quarterly, and yearly. More detailed descriptions about each of these processing levels can be found in the MISR Project Guide. The MISR data products by processing level are available.

Level 3 globally gridded products became available in July 2002. Level 2 cloud, aerosol, and land surface products became available in February 2001. Level 1 products are available from February 24, 2000 to present. These include Level 1 raw instrument data (Level 1A); radiometrically calibrated radiances (Level 1B1); geolocated, co-registered, map-projected radiances (Level 1B2); browse data; and geometric parameters on a swath-by-swath basis. Additionally, engineering, navigation, and on-board calibrator files are also available, though these are not generally required in order to make use of Level 1 image data. Static data sets also available include the Ancillary Radiometric Product (latitudes and longitudes and surface elevations) and the Ancillary Geographic Product. All currently available data products are listed on MISR Data and Information.

The MISR Browse Tool allows quick viewing of images from the MISR instrument. The color images are produced from the L1B2 Ellipsoid product for each camera reduced to 2.2km resolution. The MISR red, green and blue bands are used to create the color image, which are intentionally clipped and gamma-stretched to make cloud, ocean and land features visible. The browse images are JPEG format. Browse Tool Instructions
MISR Broswe Tool; PowerPoint slides.

 

MISR data are processed and archived at the NASA Langley Research Center Atmospheric Science Data Center (ASDC). A MISR Order and Customization Tool is available that enables users to order and customize data in a single interface. Some features are non-consecutive path and orbit search; and sorting search results by date, camera, path, orbit, and file version. Customization options are subsetting by parameter, block, and spatial coordinates; additional latitude and longitude layers, and unpacking and unscaling applicable fields; and output data in HDF-EOS stacked-block grid or conventional grid. The reformatting option, referred to as "Conventional HDF-EOS", is designed to be an easier-to-use alternative to MISR's stacked-block format. The interface currently supports two output formats:

  1. Stacked-block HDF-EOS (original file format)
  2. Conventional HDF-EOS grid

See FAQ on Customizing and Subsetting MISR products for more information.

MISR data are also available through the ASDC Data Pool (an on-line, short-term data cache that provides a Web interface and FTP access). Specially subsetted and/or reformatted MISR data products supporting field campaigns are also available. Passive FTP mode is required to access the Data Pool from the command line as "ftp -p l4ftl01.larc.nasa.gov", where the system translates to "lower case L four ft lower case L zero one .larc.nasa.gov". A UNIX C shell script method may be used to assist in downloading files from the Data Pool (Readme | Sample script). Data files are stored in directories based on data product and acquisition date. Corresponding metadata files are available in Extensible Markup Language (XML) format.

Another method to obtain MISR data is through the Reverb Search Tool. A Tutorial for this ordering tool is available.

Depending on the MISR data product, the files can be quite large (for example, a Level 2 Aerosol data product file is approximately 35 Megabytes and a Level 1B2 Radiance file is approximately 600 Megabytes).

ESDT Shortnames and Nominal File Sizes of Available MISR Data Sets
ESDT Shortname Frequency Nominal File Sizes (Mb)
MIL3DRD Daily 91
MIL3MRD Monthly 470
MIL3QRD Quarterly 524
MIL3YRD Yearly 560
MIL3DLS Daily 1
MIL3MLS Monthly 3
MIL3QLS Quarterly 4
MIL3YLS Yearly 6
MIL3DAE Daily 1
MIL3MAE Monthly 2
MIL3QAE Quarterly 3
MIL3YAE Yearly 4
MIL3DAL Daily 4
MIL3MAL Monthly 16
MIL3QAL Quarterly 22
MIL3YAL Yearly 14
MIL2ASAE 15/Day 40
MIL2ASLS 15/Day 600
MIL2TCST 15/Day 100
MIL2TCAL 15/Day 375
MIL2TCCL 15/Day 4
ESDT Shortname Frequency Nominal File Sizes (Mb)
MI1B2E (15x9)/Day 200 (Oblique), 600 (Nadir)
MI1B2T (15x9)/Day 100 (Oblique), 350 (Nadir)
MIB2GEOP 15/Day 6
MIRCCM (15x9)/Day 10
MB2LME 9 per acquisition 12
MB2LMT 9 per acquisition 12
MISBR (15x9)/Day 1
MIL1A (15x9)/Day 400 (Oblique), 900 (Nadir)
MI1B1 (15x9)/Day 400 (Oblique), 1300 (Nadir)
MIB1LM 9 per acquisition 30
MI1AENG1   2
MI1ANAV   1
MI1AMOT   1
MI1AC   75
MI1AOBC   1
MIANACP n/a 1
MIANCAGP 1 per path 110
MIANCARP n/a 5
MIANCSSC n/a 5
MIANTASC n/a 13
MISANCGM n/a 1

 

Section 2, Data Availability, of the MISR Project Guide may be helpful in determining which data products to order. Particularly helpful is Section 2.3, Product Summary.

MISR observes the entire day-lit side of each orbit. The MISR Production Report allows you to determine what data are available for an orbit range, a date range, or a path range. To obtain an inventory of MISR archive holdings for a specific location or time, submit a query through the MISR Order and Customization Tool which contains the required spatial and temporal constraints. When the query is complete, a list of MISR data files which satisfy the constraints will be displayed in the query results form.

Data for particular geographic locations can be searched via the MISR Order and Customization Tool by selecting products, region of interest, and date. The MISR Browse Tool provides information to help determine paths, orbits and block numbers for specific geographic regions. There is also an Orbit/Date Tool and a Lat/Lon to MISR Path/Block Tool available to determine MISR paths, orbits and blocks. The MISR Production Report, allows you to determine what data are currently available for an orbit range, a date range, or a path range.

The MISR Browse Tool allows quick viewing of images from the MISR instrument. The color images are produced from the L1B2 Ellipsoid product for each camera reduced to 2.2km resolution. The MISR red, green and blue bands are used to create the color image, which are intentionally clipped and gamma-stretched to make cloud, ocean and land features visible. The browse images are JPEG format. After viewing the browse images for your region, note the orbit numbers of interest. The MISR Production Report lists the most currently available data for the selected orbits. Include those orbit numbers when submitting the search for data through the MISR Order and Customization Tool.

Customization allows users to specify the contents and the output format of their MISR products. Currently available features include:
 

  • Spatial subsetting
  • Parameter subsetting
  • Additional latitude and longitude fields
  • unpack and unscale data values
  • HDF-EOS conventional grid output format

Subsetting / reformatting is available for MISR Level 1 and Level 2 Standard Data Products. The product maturity designations and quality statements of the original products are applicable to the subsetted / reformatted products. However, some of the transformations executed by the MISR Order and Customization Tool may affect data content. The following products may be customized:
 

  • MIANCAGP - MISR Ancillary Geographic Product
  • MIB2GEOP - MISR Level-1B2 Geometric Parameters
  • MIRCCM - MISR Level-1B2 Radiometric Camera-by-camera Cloud Mask
  • MI1B2E - MISR Level-1B2 Global Mode Ellipsoid-projected Radiance
  • MI1B2T - MISR Level-1B2 Global Mode Terrain-projected Radiance
  • MB2LME - MISR Level-1B2 Local Mode Ellipsoid-projected Radiance
  • MB2LMT - MISR Level-1B2 Local Mode Terrain-projected Radiance
  • MIL2TCCL - MISR Level-2 TOA/Cloud Classifiers Parameters
  • MIL2TCAL - MISR Level-2 TOA/Cloud Albedo Parameters
  • MIL2TCST - MISR Level-2 TOA/Cloud Stereo Parameters
  • MIL2ASAE - MISR Level-2 Aerosol Parameters
  • MIL2ASLS - MISR Level-2 Land Surface Parameters

One MISR data file is the full swath of data (from terminator to terminator), and the MISR swath-based products are very large. Many users will be interested only in those parts of the swath that cover their region of interest. The MISR Order and Customization Tool enables users to order and customize data in a single interface. Customization options are subsetting by parameter, block, and spatial coordinates; additional latitude and longitude layers, and unpacking and unscaling applicable fields; and outputting data in HDF-EOS stacked-block grid or conventional grid.

Stacked-block HDF-EOS format is a MISR specific extension to the HDF-EOS library that is only used by MISR and is not widely supported by third party data analysis tools. Tools which support HDF-EOS or HDF can usually import stacked-block data to a limited extent. Two problems commonly encountered are: 1) piecing together the MISR blocks so they are aligned correctly with respect to each other; and 2) geolocating the MISR data in a map context. Many tools do not support geolocation of the stacked-block HDF-EOS format. A detailed discussion of the stacked-block HDF-EOS format including instructions on how to write software to geolocate MISR data are discussed in Appendix A of the Data Product Specifications Document.

Stacked-block Stacked-block
vs Aligned File
Stacked-block Background. Stacked-block vs aligned file.

 

The conventional HDF-EOS format is an alternative format that uses only common HDF-EOS elements, specifically excluding use of the stacked-block extensions. As a result, the conventional HDF-EOS format should be easily imported into any tools that support generic HDF-EOS. In practice however, there are still many tools which have only limited support for HDF-EOS. Conversion to conventional HDF-EOS format attempts to reproduce the data content of the original products, only changing the data format. However, there are some notable differences in the data content for some fields which are discussed below. Geolocation is based on the standard parameters used by the General Cartographic Transformation Package (GCTP) library which is distributed with the HDF-EOS library. Data are map projected using the same Space Oblique Mercator (SOM) projection as the original products.

Conventional
Grid Product
Stacked-block
vs Aligned File
Conventional grid product. Stacked-block vs aligned file.

 

The choice of format largely depends on the tools you are using. Some MISR specific tools, such as misr_view, only support stacked-block format. Tools with only generic support for HDF or HDF-EOS, will be able to display stacked-block data a block-at-time, but will not automatically stitch blocks together with the proper alignment, and will not provide geolocation information.

  • If you are using MISR-specific tools such as misr_view or the MISR ENVI Tools, you should use the stacked-block format.
  • If you are using generic HDF or HDF-EOS tools, you should use the conventional format.

Tools supporting stacked-block format are listed on the Tools page under MISR "Multi-angle Imaging SpectroRadiometer (MISR) and AirMISR Software and Tools".

Most tools that generically support HDF or HDF-EOS should be able to import conventional format. However, tools that only support generic HDF format will not automatically import the HDF-EOS geolocation information.

ENVI version 4.0 (a product of ITT Visual Information Solutions), can successfully import and display most data fields in a conventional HDF-EOS format file. ENVI does not automatically import HDF-EOS geolocation parameters, but this information can be entered manually, using provided ENVI instructions. ENVI does not support import of HDF fields with more than three dimensions, including the X, Y, spatial dimensions. Therefore, MISR parameters including both camera and band dimensions cannot be displayed in ENVI.

In the conversion from stacked-block to conventional format, data is reprojected onto a flat 2-dimensional grid, so that the MISR blocks can be aligned appropriately with respect to each other. For most fields this reprojection is trivial, requiring no resampling; i.e. the reprojected data is identical in content to the original stacked-block format.

 

The exception occurs for data at resolutions of 35.2 km and 70.4 km. The root of this problem lay within the stacked-block format, which allows the MISR block locations to be offset with respect to each other by multiples of 17.6 km. At pixel resolutions larger than 17.6 km, the block offset is a fraction of a pixel. Therefore, the MISR data is actually computed over an irregular grid in which the pixels are not lined up in regular columns, but instead are shifted by fractions of their size as shown in the illustration of geolocation error (PDF).

 

This problem affects the following parameters:

Product Grid Resolution
Level 2 TOA/Cloud Albedo (MIL2TCAL) AlbedoParameters_35.2_km 35.2 km
Level 2 TOA/Cloud Stereo (MIL2TCST) DomainParams 70.4 km
Level 2 TOA/Cloud Classifiers (MIL2TCCL) CloudClassifiers_35.2_km 35.2 km
Level 2 Land Surface (MIL2ASLS) DomParamsAer 70.4 km

 

Data for all parameters listed above are shifted by up to one-half a pixel, to align with the nearest pixel in the conventional HDF-EOS grid. All the data numbers, however, remain the same as those in the original products. The effect is a geolocation error of up to 17.6 km for 35.2 km resolution parameters; and up to 35.2 km for 70.4 km resolution parameters. To account for this error, "Latitude" and "Longitude" fields are provided which give the original location of each pixel prior to shifting.

 

This means there will be two sources of geolocation information for the above parameters. First is the implicit geolocation of each pixel as defined by the GCTP map projection information. This implicit geolocation information will have an error of up to one-half a pixel. Second is the "Latitude" and "Longitude" fields which explicitly specify the lat/lon location for the center of each pixel. The "Latitude" and "Longitude" fields will always have the correct geolocation information. By comparing the implicit lat/lon against the explicit lat/lon, one can determine which pixels have been shifted, and by how much.

See MISR Data and Information for a complete list of data products and the Data Product Specifications for detailed descriptions of the parameters within those products. The main products are the ellipsoid (MI1B2E) and terrain (MI1B2T) projected radiances for each of the cameras, the browse images (MISBR), geometric (MIB2GEOP) parameters (sun and view angles), and the cloud and sun glint mask (MIRCCM).

Level 1A data (the Reformatted Annotated Product, file names containing "FM_SCI") contain raw digital counts from the MISR camera charge-coupled device (CCD) focal planes. At Level 1B1 (the Radiometric Product, file names containing "RP"), the values correspond to calibrated radiances. At Level 1B2 (the Georectified Radiance Product, file names containing "GRP_ELLIPSOID" or "GRP_TERRAIN") the radiance data are geolocated, and geometric co-registration of the data from the different bands and camera angles is performed by resampling to a Space Oblique Mercator (SOM) grid. L1A and L1B1 use the HDF-EOS "swath" interface, and L1B2 uses the HDF-EOS "grid" interface. Most users do not need the L1A and L1B1 data.

The MISR instrument can acquire measurement in Global Mode (GM), Local Mode (LM), and Calibration. Global Mode is the normal acquisition with pole to pole coverage on the day-lit side or the orbit, full resolution (275m) in all 4 nadir bands and the red band of all other angles and 1.1km sampling in all other off nadir bands.

MISR can be configured to disable the on-board data averaging and provide high resolution images in all 36 channels for selected targets and observation times. This capability is referred to as Local Mode (LM). The result is a scene with a crosstrack pixel spacing of 275 meters, with downtrack sampling also at 275 meters, over a spatial area of approximately 300 kilometers downtrack by 360 kilometers crosstrack. LM acquisition can be requested by providing latitude and longitude coordinates, dates, and explanation of data need to User and Data Services.

Global
  • Pole-to-pole coverage on orbit dayside
  • Full resolution in all 4 nadir bands, and red band of off-nadir cameras (275-m sampling)
  • 4x4 pixel averaging in all other channels (1.1-km sampling)
Local
  • Implemented for pre-established targets (1-2 per day)
  • Provides full resolution in all 36 channels (275-m sampling)
  • Pixel averaging is inhibited sequentially from camera Df to camera Da over targets approximately 300 km in length
Calibration
  • Implemented bi-monthly
  • Spectralon solar diffuser panels are deployed near poles and observed by camera and a set of stable photodiodes

 

The L1B2 product contains a hierarchy of metadata fields to assist you in determining which data are relevant. All L1B2 files begin with block number 1, even though block processing rarely begins that early. Refer to the file metadata attributes "Start_block" and "End block" in order to locate valid data. Note: The missing underscore in End block is real. The L1B2 per-block metadata also contains a data valid flag which is normally set to 1 for blocks within the Start_block and End block range. In rare cases, the L1B2 software is forced to skip an entire block in order to complete. In these cases, the data valid flag for that block is set to 0. Illustration of Blocks Paths/Blocks Example
Stacked-block background. Example of MISR paths and blocks.

 

Most of the time that MISR is acquiring Earth imagery it operates in a configuration called Global Mode, which allows the spatial resolution to be set for each individual channel (there are 36 channels on MISR: 4 bands at each of 9 angles). Currently Global Mode is defined to provide 275-m resolution data in all bands of the An (nadir) camera and in the red band of all the off-nadir cameras (this is the highest resolution available and is called 1x1 data since it involves no on-board pixel averaging). In the remaining channels 4 samples x 4 lines are averaged within the instrument to create a 4x4, or 1.1-km resolution sample. In the L1B2 product, 1x1 data map to a 2048x512 array, whereas 4x4 data map to a 512x128 array. Thus, samples 1-4 in lines 1-4, for example, in 2048x512 data correspond on the SOM grid to the same location as sample 1, line 1, in a 512x128 array.

In order to resample the data from the nine MISR cameras to the SOM grid, it is necessary to assign an altitude to each location on the grid. In the Ellipsoid product, this altitude is represented by the WGS84 ellipsoid. In the Terrain product, it is the altitude of Earth's terrain. Both products are broken arranged into 180 blocks measuring 563.2 km (cross-track) x 140.8 km (along-track). The Terrain product does not contain valid data for blocks that are considered to be completely over water.
 

Illustration of Ellipsoid vs Terrain Projection
Objects along a camera line-of-sight. Camera-to-camera co-registration.

 

Any MISR target which is not at the altitude at which the L1B2 product is registered will show a residual misregistration, or parallax, from one angle to another. This parallax is a function of the target's height relative to the projection altitude. For example, to visualize both topographic relief and cloud altitudes stereoscopically, the Ellipsoid is the appropriate product. Applications which require the data to be co-registered at the land surface altitude should use the Terrain product.

For blocks which contain no land, the 14 most significant bits (MSB) of the Terrain product are assigned the fill value 16379, and the actual image data must be obtained from the Ellipsoid product.

MISR Level 1B2 data products use various high data values to signify fill, and one of the fill values (16377) in the 14 MSB's of the scaled radiances signifies that this location on the SOM grid was obscured from the camera's view by intervening topography. Because greater amounts of topographic obscuration occur at the more oblique angles, the prevalence of this particular fill value increases as the view angle increases. This particular fill value does not apply to the Ellipsoid product, because for each sample, whatever radiance was observed along the line of sight is projected to the ellipsoid grid location.

The Aerosol data (MIL2ASAE) contains aerosol optical depth, aerosol compositional model, ancillary meteorological data, and related parameters on a 17.6 km grid. The Land Surface data (MIL2ASLS) includes bihemispherical and directional-hemispherical reflectance (albedo), hemispherical directional and bidirectional reflectance factor (BRF), BRF model parameters, leaf-area index (LAI) and fraction of photosynthetically active radiation (FPAR), and normalized difference vegetation index on a 1.1 km grid. MISR Top of Atmospheric/Cloud Stereo (MIL2TCST) data parameters include a stereoscopically-derived cloud mask and cloud height on a 1.1 km grid, and reflecting level reference altitude on a 2.2 km grid. Cloud motion parameters are calculated on a 70.4 km grid. The TOA/Cloud Albedo (MIL2TCAL) data contain local albedo values, and the TOA/Cloud Classifiers (MIL2TCCL) contain altitude-binned cloud classifications and angular cloud fractions. Further information is available at MISR Data and Information.

To obtain the complete information about the aerosol models, you will need to order the MISR Aerosol Climatology Product (MIANACP) which contains the Aerosol Physical and Optical Properties (APOP) and the Mixture files. The Mixture file lists the pure particles in each model identifier. The APOP then gives the detailed information for the pure particles. More information on the MISR aerosol model is available from the MISR publications page and the Algorithm Theoretical Basis Document (ATBD).

The Level 3 Component Global Georectified Radiation Product (CGGRP), Component Global Land Surface Product (CGLS), Component Global Aerosol Product (CGAS), and Component Global Albedo Product (CGAL) are generated for daily, monthly, quarterly, and yearly time periods. These data are globally gridded on several grids including 0.5°x0.5°, 1°x1°, or 10°x10°. Selected parameters from these products are available for viewing from MISR Level 3 Imagery. Further information is available at MISR Data and Information.

The Level 3 products are globally gridded statistical summaries of a range of parameters from select Level 1 and Level 2 products. The Levels 1 and 2 products are in swaths, each derived from a single MISR orbit, where the imagery is 360 km wide and approximately 20,000 km long. At Level 3 the product parameters from multiple swaths are combined to make complete, global maps. The Level 3 products are averages of select Level 2 parameters on daily, monthly, quarterly and annual time scales. The MISR Level 3 Imagery provides easy access to images of select parameters within these products.

The "Clim-Likely" aerosol climatology data set was developed as an initial step in identifying a range of components and mixtures for the MISR Standard Aerosol Retrieval Algorithm climatology, and as one standard against which to compare MISR aerosol air mass type retrieval results. Six component aerosols included in the model were medium and coarse mode mineral dust, sulfate, sea salt, black carbon, and carbonaceous aerosols. Five aerosol air mass "Mixing Groups" and thirteen sub-groups were identified from a cluster analysis of the entire set of data. Each Mixing Group contains the four most abundant component particles in the column for climatologically common aerosol air masses. Each sub-group identifies the dominant particles within the Mixing Group. The data are derived from 'typical-year' aerosol transport model results and are available for individual 1° x 1° grid boxes or as global monthly files. The "Clim-Likely" aerosol climatology data set is available from the ASDC. "Clim-Likely" documentation and examples are available from this reference: Kahn, Ralph, Pranab Banerjee, and Duncan McDonald (2001). The sensitivity of multi-angle imaging to natural mixtures of aerosols over ocean. J. Geophysical Res., 106 (D16), 18219-18238 (PDF).

MISR data and imagery are available for many field campaigns. Select data products are subset for the region and dates of interest. Special gridded regional products may be available as well as Local Mode data for select targets within the field campaign region. Specific details on MISR-supported field campaigns are available.

At Level 1A, the 14 most significant bits (MSB) directly represent the raw digital count from the camera's Charge-Coupled Device (CCD). The 2 least significant bits (LSB) of the 16-bit data values are data quality indicators (DQI). A DQI of 0 means the data meet all specifications; 1 means some degradation in quality has occurred but the data are still valid; 2 means the data should not be used for scientific analysis; and 3 means the data are not usable. At Level 1B1, the image data and the data quality indicators are stored as separate fields. The image data values represent "scaled radiances", which means that they must be multiplied by a scale factor to obtain radiance in units of Watts/square meters/steradian/micrometer. These band-by-band scale factors are stored in the swath metadata of L1B1 files, and are found within the attributes of the swath structures. The data quality indicators follow the same convention described above.

For Level 1B2 data, the image data and the data quality indicators are once again packed into 16-bit words. The 14 MSB's represent "scaled radiances", and the 2 LSB's are DQI values that follow the same convention described above. The conversion from scaled radiance to radiance (Watts/square meters/steradian/micrometer) requires multiplication by a scale factor. These band-by-band scale factors are stored in the grid metadata of L1B2 files, and are found within the attributes of the grid structures. Note that certain high values of the scaled radiances at L1B1 and L1B2 are reserved for fill, as described in the Data Product Specification Document.

Since November 2002 (product version 0016 and later), the MISR L1B2 products contain parameters within the file that make it easier to convert to BRF. The BRF conversion factor for each band is derived from the equation:

(pi * SunDistanceAU2) / (std_solar_wgted_height * cos(SolarZenith))

This factor can be used to calculate the BRF:

BRF = BRF conversion factor * Radiance

The Radiance may be obtained from the Radiance/RDQI by right-shifting 2 bits, then multiplying the result by the Scale factor (radiometric) contained in the Radiance Grid Metadata.

The value is stored in the MISR Ancillary Geographic Product (AGP), of which there are 233 unique files, one for each of the World Reference System-2 (WRS-2) paths. Like the L1B2 products, these are divided into blocks, and the fields within the "Standard" grid of the AGP are provided at 1.1-km sampling. The average elevation over a 1.1-km grid sample are provided in the "AveSceneElev" field. AGP files can be obtained from the MISR Order and Customization Tool and through the ASDC Data Pool.

This process is described in the MISR Data Product Specifications, Appendix A. There are two methods for doing this:

  1. Look up the Lat/Lon of the corresponding block, line, sample in the Ancillary Geographic Product (AGP) data sets.

    MISR geolocation information is located in the MISR Ancillary Geographic Product (AGP) files. The fields "GeoLatitude" and "GeoLongitude" contain the desired information. These values are stored on the "Standard" (1.1 km) grid of the AGP; you may need to interpolate or extrapolate if the parameter you are working with is on a different grid. Latitudes are geodetic, and longitudes are relative to the Greenwich meridian, positive to the east and negative to the west.

    You will need to obtain the AGP file that corresponds to the path of the data you are trying to geolocate. The path is given in the MISR data file name using the format _Pxxx_ where xxx is the path number (1-233).

  2. Mathematically convert the SOM block, line, and sample (pixel) to latitude and longitude. This is a two-step process. Algorithms are provided in the DPS Appendix A.

    • Convert(block, line, sample) <=> SOM(x,y)
      Requires several metadata values from the data file and some arithmetic
    • Convert SOM(x,y) <=> Lat/Lon
      Requires use of GCTP (General Coordinate Transformation Package) map projection coordinate conversion library in HDF-EOS distribution or some other software that incorporates GCTP, such as IDL.

The Geometric Parameters files (file names containing "GP_GMP") contain, within each SOM block, solar zenith angle, solar azimuth angle, and view zenith angle and view azimuth angle for each of the 9 cameras. The geometry is established by the MISR camera views, the Sun, and the Terra orbit. To conserve data volume, these parameters are provided on a 17.6-km grid, so you will find the data blocks to be dimensioned 32x8. To get values at 1.1 km or 275 m, you can either interpolate these arrays, or, since the geometric parameters vary slowly spatially, the nearest neighbor should provide sufficient accuracy for most applications. Solar zenith and azimuth are also included in L1B2 file version 16 and later.

When you select a link under "Data Retrieval", current users must log in and new users must register.

  1. Enter your email address.
  2. Enter the password of your choice.
  3. Enter the password again in the "Password Again: (New Users Only!)" field.
  4. Select "Submit".
  5. Follow the directions to complete the form and register as a new user.

If you forgot your password or need to update your user information, you will need to register again. Please see "How do I register for data access?" for instructions.

The SSE data provider requests that the following acknowledgement be used when SSE data products are used in a publication:

"These data were obtained from the NASA Langley Research Center Atmospheric Science Data Center POWER Project."

  1. On the SSE web site, select "Meteorology and Surface Energy".
  2. There are 2 ways to obtain data:
    • Select "click on desired map location"
    • Select "Enter latitude and longitude"
    • Log in.
  3. If you selected the "Enter latitude and longitude", enter the latitude and longitude. Select "Submit".
  4. If you selected "click on desired map location", follow directions and "Submit"
  5. Choose the parameters of interest and select "Submit".
  6. The resulting page contains monthly averages for each of the selected parameters.
  1. On the SSE web site, select "Meteorology and Surface Energy".
  2. Select "Global or Regional Plots".
  3. Log in.
  4. Select the desired region on the map (or leave blank for information for the entire globe).
  5. The first click indicates the starting position of your region and the second click specifies the range.
  6. Choose the parameter of interest and select "Submit".
  7. The resulting page contains a plot for the selected parameter.
  1. On the SSE web site, select "Meteorology and Surface Energy".
  2. Select "Global Data Sets".
  3. Log in.
  4. Select the desired parameter.
  5. The resulting page contains the monthly and annually averaged values for the selected parameter.
  1. On the SSE web site, select "Meteorology and Surface Energy".
  2. Select "Regional data subsets".
  3. Log in.
  4. Enter both Latitude and Longitude of two diagonal corners of a region.
  5. Select from either box 1 OR box 2:
    • Box 1: choose a month and a parameter of interest, and select "Submit".
    • Box 2: select a parameter, and select "Submit".
  6. The resulting page contains data for the monthly average for the selected parameter.
  1. On the SSE web site, select "Meteorology and Surface Energy".
  2. Select "Daily Data".
  3. Log in.
  4. Enter Latitude and Longitude
  5. Select Start Date and End Date.
  6. Select parameter(s) from the "Download multiple parameters in a column formatted text file" list
  7. Select one parameter of those just chosen from the "Plot one parameter" list.
  8. Select "Submit".
  9. The resulting page displays a plot of the selected parameter with an option to view the parameters chosen for downloading in a text file.
  1. On the SSE web site, select "Meteorology and Surface Energy".
  2. Select "Interannual Variability".
  3. Log in.
  4. Enter Latitude and Longitude.
  5. Select Start Year and End Year.
  6. Select a parameter.
  7. Select "Submit".
  8. The resulting page contains a table of values for the monthly averages of the selected parameter.
  1. On the SSE web site, select "Ground Site".
  2. Select "Monthly Plots".
  3. Log in.
  4. There are 2 ways to select a ground site:
    • Enter Latitude and Longitude to locate the site closest to that Latitude and Longitude.
    • Select a location (country) to further locate a site.
    • Select "Submit".
  5. There are 2 ways to view the data:
    • Select "Monthly Average" and "Submit".
      You will see a plot of the entire data set averaged by month and the values listed below.
    • Select the year and month of interest and "Submit".
      You will see a plot of the daily average for that month and the values listed below.
  1. On the SSE web site, select "Renewable Software Application Inputs".
  2. Select "HOMER data access".
  3. Log in.
  4. There are 2 ways to obtain data:
    • Enter Latitude and Longitude and "Submit".
    • Pick a location geographically. Follow directions and "Submit"
  5. The resulting page contains data and graph of the daily values. There is also the ability to get the data as plain text.
  1. On the SSE web site, select "Renewable Software Application Inputs".
  2. Select "RETScreen data access".
  3. Log in.
  4. There are 2 ways to obtain data:
    • Enter Latitude and Longitude and "Submit".
    • Pick a location geographically. Follow directions and "Submit"
  5. The resulting page contains energy analysis data.

TES began making measurements on August 22, 2004. The routine TES observation mode is to produce global survey standard products spanning 16 orbits on a 50% duty cycle, or approximately every other day. The "off" days can be used for special observations such as intensive campaigns to observe volcanic eruptions, biomass burning, and pollution events.

  • TES Level 1B data files contain radiometric calibrated spectral radiances and their corresponding noise equivalent spectral radiances (NESR). The geolocation, quality and some engineering data are also provided.
  • A Level 1B data file contains data from a single TES orbit for one focal plane. Note that a TES orbit starts at the South Pole Apex.
  • A Level 1B granule contains four files for a single orbit, one file for each of the four focal planes. Note that a granule is the orderable quantity of data.
  • The table below illustrates the TES Level 1B file naming conventions.

    ESDT Short Name File Name Product
    TL1BN TES-Aura_L1B-Nadir_FPfp_rrun id-oorbit number_version id.h5 Standard
    TL1BSOL TES-Aura_L1B-SO-Low_FPfp_rrun id-oorbit number_version id.h5 Special Observation/Low Resolution
    TL1BSOH TES-Aura_L1B-SO-High_FPfp_rrun id-oorbit number_version id.h5 Special Observation/High Resolution
    • fp represents the two-character focal plane identifier: 1A, 1B, 2A or 2B
    • run id represents the ten-digit run identification number.
    • orbit number represents the starting five-digit Absolute Orbit number, which is the same as the Aura orbit number at the time of the South Pole apex crossing.
    • version id represents the version identification number, which is used to keep track of file format and file content changes.
      For more information about file version identification, see the TES Data Products Specification document.
    • .h5 extension denotes the use of HDF5 file format.
  • TES Level 2 files contain measurements of a single molecular species or temperature. The Level 2 Ancillary Data Product contains information such as geolocation and spacecraft position, which are common to the individual Level 2 species and temperature Standard Product files. A TES Level 2 granule contains a single data file.
  • The tables below illustrates the TES Level 2 file naming conventions.

    Standard Products
    ESDT Short Name File Name
    TL2CH4N TES-Aura_L2-CH4-Nadir_rrun id_version id.he5
    TL2CON TES-Aura_L2-CO-Nadir_rrun id_version id.he5
    TL2H2ON TES-Aura_L2-H2O-Nadir_rrun id_version id.he5
    TL2O3N TES-Aura_L2-O3-Nadir_rrun id_version id.he5
    TL2ATMTN TES-Aura_L2-ATM-TEMP-Nadir_rrun id_version id.he5
    TL2ANC TES-Aura_L2-ANCILLARY_rrun id_version id.he5

    Special Observations
    ESDT Short Name File Name
    TL2CH4NS TES-Aura_L2-CH4-SO-Nadir_rrun id_version id.he5
    TL2CONS TES-Aura_L2-CO-SO-Nadir_rrun id_version id.he5
    TL2H2ONS TES-Aura_L2-H2O-SO-Nadir_rrun id_version id.he5
    TL2O3NS TES-Aura_L2-O3-SO-Nadir_rrun id_version id.he5
    TL2TNS TES-Aura_L2-ATM-TEMP-SO-Nadir_rrun id_version id.he5
    TL2ANCS TES-Aura_L2-ANCILLARY-SO_rrun id_version id.he5
    • run id represents the ten-digit run identification number.
    • version id represents the version identification number, which is used to keep track of file format changes.
      For more information about file version identification, see the TES Data Products Specification document.
    • .he5 extension denotes the use of HDF-EOS5 file format.
  • The objective of TES SDP L3 subsystem is to interpolate the L2 atmospheric profiles collected in a Global Survey onto a global grid uniform in latitude and longitude that will provide a 3-D representation of the distribution of atmospheric gasses. The L3 standard data products are composed of L3 HDF-EOS grid data.
  • The L3 standard product files are implemented using the HDF-EOS 5 file format. HDF-EOS 5 files have a default extension of ".he5". The ECS Local Granule ID (filename) for a L3 standard product is constructed using the following template:

    File Type File Name Convention
    daily TES-Aura_L3-<species>_<run id>_<version id>.he5
    8-day TES-Aura_L3-<species>-8D<year><doy>_<version id>.he5
    monthly TES-Aura_L3-<species>-M<year><month>_<version id>.he5
    Notation Format Description
    <doy> dddd <doy>: first day of the 8-day period
    d : day of year format placeholder
    ddd : 3-digit number representing day of year
    <month> mmm m : month format placeholder
    mm : 2-digit number representing month
    <run id> rnnnnnnnnnn r : Run ID format placeholder
    nnnnnnnnnn : string representing 10-digit Run ID
    <version id> Fff_cc F : File format placeholder
    ff : 2-digit version number reflecting file format changes
    cc : 2-digit version number reflecting content changes
    <year> yyyy yyyy: 4-digit number representing year