Multi-angle Imaging SpectroRadiometer (MISR) Langley DAAC Project Guide
|
|
Multi-angle Imaging SpectroRadiometer (MISR) Langley DAAC Project Guide |
|
|
Summary:MISR, the Multi-angle Imaging SpectroRadiometer, is an instrument unlike any that has flown in space before. Most satellite instruments look either straight down or toward the edge of our planet. But MISR records images of the Earth simultaneously at 9 different angles in each of 4 color bands. MISR's 36 simultaneous spectral-angular images allow derivation of aerosol optical depth and particle type, characterization of scene type, surface albedo, and bi-directional reflectance, and information about cloud properties. MISR was built for NASA by the Jet Propulsion Laboratory in Pasadena, California. It is part of NASA's first Earth Observing System spacecraft, the Terra spacecraft, which was launched into polar orbit from Vandenberg Air Force Base on December 18, 1999. More detailed descriptions of this project may be found at the MISR web site. |
Multi-angle Imaging SpectroRadiometer (MISR)
See the Summary section above.
The purpose of the MISR experiment is to acquire 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. Select the
thumbnail image a the right to see an enlarged cartoon of the scientific
applications of MISR. The following text discusses these applications.
Climate is what makes the Earth habitable. And the climate is constantly changing - as a consequence of both natural processes and human activities. We care a great deal about even small changes in Earth's climate, since they can affect our comfort and well-being, and possibly our survival. Even a few years of below-average rainfall, an unusually cold winter, or a change in emissions from a coal-burning power plant, can influence the quality of life of people, plants, and animals in the region involved.
The goal of NASA's Earth Observing System (EOS) is to increase our understanding of the climate changes that are occurring on our planet, and the reasons for these changes, so we are better equipped to anticipate and prepare for the future. The MISR instrument is a part of EOS. Its role is to measure how much sunlight is scattered in different directions under natural conditions. This will help quantify the amount of solar energy that heats the Earth's surface and atmosphere, and the changes that occur in these quantities over the six-year nominal lifetime of the MISR instrument.
From the MISR observations, we will also learn more about those components of the Earth environment that scatter sunlight in the first place: particles in the atmosphere, the planet's surface, and clouds. MISR will monitor changes in surface reflection properties, in atmospheric aerosol content and composition, and in cloudiness. We will use these data to study the effects of land use changes, air pollution, and volcanic eruptions, as well as processes such as desertification, deforestation, and soil erosion. As part of the EOS program, computer models that predict future climate will be improved by the results of these studies.
Further discussion of the science objectives of the MISR experiment can be found on the MISR web site's Science Goals and Objectives page.
Earth Sciences
Atmospheric Sciences
Global coverage every nine days, with repeat coverage between nine days at the equator and two days at the poles. Swath width in all cameras is 360 km. The polar orbit of the Terra spacecraft has an inclination of 98.3 degrees, so that MISR is able to view the Earth's surface up to 81 degrees latitude.
The MISR instrument consists of nine pushbroom cameras. It is capable of global
coverage every nine days, and flies in a 705-km descending polar orbit. The
cameras are arranged with one camera pointing toward the nadir (designated An),
one bank of four cameras pointing in the forward direction (designated Af, Bf,
Cf, and Df in order of increasing off-nadir angle), and one bank of four
cameras pointing in the aftward direction (using the same convention but
designated Aa, Ba, Ca, and Da). Images are acquired with nominal view angles,
relative to the surface reference ellipsoid, of 0, 26.1, 45.6, 60.0, and 70.5
degrees for An, Af/Aa, Bf/Ba, Cf/Ca, and Df/Da, respectively. Each camera uses
four Charge-Coupled Device (CCD) line arrays in a single focal plane. The line
arrays consist of 1504 photoactive pixels and each line is filtered to provide
one of four spectral bands. The spectral band shapes are nominally gaussian,
centered at 443, 555, 670, and 865 nm.
MISR contains 36 parallel signal chains corresponding to the four spectral
bands in each of the nine cameras. Each signal chain contains the output from
the detectors in each CCD array. The zonal overlap swath width of the MISR
imaging data (that is, the swath seen in common by all nine cameras along a
line of constant latitude) is 360 km, which provides global multi-angle
coverage of the entire Earth in 9 days at the equator, and 2 days near the
poles. The cross-track instantaneous field-of-view (IFOV) and sample spacing of
each pixel is 275 m for all of the off-nadir cameras, and 250 m for the nadir
camera. Along-track IFOV's depend on view angle, ranging from 214 m in the
nadir to 707 m at the most oblique angle. Sample spacing in the along-track
direction is 275 m in all cameras. The instrument is capable of buffering the
data to provide 2 sample x 2 line, 4 sample x 4 line, or 1 sample x 4 line
averages, in addition to the mode in which pixels are sent with no averaging.
The averaging capability is individually selectable within each of the 36
channels.
| Parameters | Value |
|---|---|
| Camera view angles at Earth's surface | 0.0 degrees (nadir), 26.1, 45.6, 60.0, and 70.5 degrees, both fore and aft of nadir |
| Swath width | 360 kilometers overlap between cameras (9-day global coverage) |
| Cross-track x along-track pixel sampling (commandable) | 275 x 275 meters 550 x 550 meters 1.1 x 1.1 kilometers 275 x 1.1 kilometers |
| Spectral bands (solar spectrum weighted) | 446.4, 577.5, 671.7, 866.4 nanometers |
| Spectral bandwidths | 41.9, 28.6, 21.9, 39.7 nanometers |
| Charge-Coupled Device sensor architecture | 4 lines x 1504 active pixels, in each of 9 cameras |
| Absolute radiometric uncertainty | 3 percent (1 sigma) at maximum signal |
| Mass | 149 kilograms |
| Power | 83 watts average, 131 watts peak |
| Data rate | 3.9 Megabits per second, average |
There are several observational modes of the MISR instrument. Global Mode (GM) refers to continuous operation with no limitation on swath length. Global coverage in a particular spectral band of one camera is provided by operating the corresponding signal chain continuously in a selected resolution mode. Any choice of averaging modes among the nine cameras that is consistent with the instrument power and data rate allocation is suitable for Global Mode. Additionally, Local Mode (LM) provides high resolution images in all 4 bands of all 9 cameras for selected Earth targets. This is accomplished by inhibiting pixel averaging in all bands of each of the cameras in sequence, one at a time, beginning with the first camera to acquire the target and ending with the last camera to view the target. The instrument geometry limits the along-track length of Local Mode targets to about 300 km. Finally, in Calibration Mode (CM) the on-board calibration hardware is deployed and calibration data are acquired for the cameras. Calibration data will be obtained for each spatial sampling mode (see above) by cycling each channel through the various modes during the calibration period. Calibration Mode will be used on a monthly basis during routine mission operations, although early in the mission it will be used more frequently.
Science validation consists of intercomparisons of parameters generated using
MISR algorithms operating on radiance measurements from MISR aircraft simulator
or spaceborne instruments with similar products generated using conventional
ground-based solar and atmospheric observations, together with conventional
methods of analysis and inversion. These intercomparisons may also serve in
some instances to validate the assumed aerosol climatology and surface
reflectance models used in the retrievals.
Validation of the aerosol and surface retrieval algorithms relies on several
sources of data including aircraft observations, together with field
observations of downwelling diffuse sky spectral radiance and irradiance, the
direct solar irradiance component and the surface spectral bidirectional
reflectance factor (BRF). In contrast to MISR spacecraft or aircraft
observations of the upwelling radiation field at the top or middle of the
atmosphere, ground-based deployments obtain downwelling measurements of sky
spectral diffuse radiance and irradiance, together with the directly
transmitted solar irradiance.
The validation approach adopted for MISR consists of comparing geophysical
parameters generated using MISR algorithms adapted to use with aircraft; MISR
algorithms adapted to retrievals using the downwelling radiation field at the
bottom-of-the-atmosphere; and using independent algorithms on ground-based
observations in order to secure ground-based estimates of aerosol spectral
optical depth, effective size distribution, phase function, and single
scattering albedo. Validation of cloud parameters focuses on the RLRA
retrieval, using stereo imagery, accurate manual and automated
stereo-photogrammetric techniques, and comparison with MISR algorithm results.
A more expansive discussion of the instrument and experiment design can be found on the MISR website's Instrument Description page.
The generation of standard MISR science data products at the LaRC DAAC can
be divided into five production steps. Each step has at least one primary
output product, but may have other secondary output products. It is convenient
to think of these five steps as occurring in sequence, with the predecessor
producing at least one complete product, a portion of which is the primary
input for the successor. The five steps are:
Each of these steps corresponds to processing levels of a product generation flow, as shown inthe above diagram. These levels conform to the EOS scheme from Level 1 toLevel 3, where each successive level has a higher degree of processing.
Level 1 Products - These have been processed and calibrated to remove many of the instrument effects. The resulting products thus contain minimal instrument artifacts and are most suitable for subsequent scientific derivations.
Level 1A: Reformatted Annotated Product - The raw data from the instrument, which is intricately structured and compressed, is reformatted into more straightforward computer files. At the same time, many checks are made on the quality of the data to ensure that the instrument is working correctly. There are three categories of products at Level 1A:
Only thefirst of these three categories, science data, is processed to products higherthan Level 1A.
Level 1B1: Radiometric Product - Two types of processing are included in this product. Firstly, the Radiance Scaling operation converts the camera's digital number output to a measure of energy incident on the front optical surface. The measurement is expressed in units called radiance (energy per unit area, wavelength, and solid angle) as defined by the international scale. Secondly, Radiance Conditioning modifies the radiances to remove instrument-dependent effects. Specifically, image sharpening is provided, and focal-plane scattering is removed. Additionally, all radiances are adjusted to remove slight spectral sensitivity differences among the 1504 detector elements of each spectral band and each camera. In addition to the Level 1B1 radiometric product for MISR's Global Mode imagery, there is a separate Level 1B1 product for each high-resolution Local Mode scene.
Level 1B2: Georectified Radiance Product - The nine sets of imagery from the nine cameras are registered to one another and to the ground. This is an image processing application made necessary because the nine views of each point on the ground are not acquired simultaneously (images from cameras at the two extreme angles are 7 minutes apart.) This product is mapped into the Space Oblique Mercator (SOM) map projection. The product embraces three sets of parameters:
In addition to the Level 1B2 Global Mode imagery, there is a separate Level 1B2 product for each high-resolution Local Mode scene.
Level 2 Products - These are geophysical measurements derived from the instrument data.
Level 2TC: Top-of-Atmosphere/Cloud Product - This product contains measurements of top-of-atmosphere bidirectional reflectance factors, stereoscopically-derived cloud and land (reflecting level) elevation, cloud fraction, cloud texture, and other related parameters. The horizontal sampling of this product is 2.2 km, except for a few parameters at 1.1 km and 17.6 km.
Level 2AS: Aerosol/Surface Product - This product includes a range of
parameters such as tropospheric aerosol optical depth; aerosol composition and
size; surface directional reflectance factors and bi-hemispherical reflectance;
and other related parameters. The horizontal sampling of this product is 17.6
km.
Level 3 Products - These are global maps of a range of parameters from the 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 will typically be monthly averages of various Level 2 parameters. Note that Level 3 MISR products are expected to be available sometime towards the end of the first year of the mission.
Production of standard products at the DAAC includes a dependency on the MISR Science Computing Facility (SCF) for certain functions. For example, there is critical dependence on calibration parameters and lookup data such as threshold data sets, climatologies, model data sets or the like. These functions are separated from DAAC activities because they require close day-by-day scrutiny by the MISR science team. Updates to these data structures occur infrequently compared to the rate of standard product generation, and therefore fit into the more limited processing capabilities of the SCF. Other essential functions that have activity at the SCF include quality assessment, algorithm validation, software development, and instrument operations.
Select the thumbnail diagram at the right to see the hierarchy of the product
generation executables (PGEs) used to generate the MISR standard products. This
illustrates how each successively higher product is created from the lower
level products.
In addition to the product files, most users need to be cognizant of certain ancillary files associated with MISR data product generation. In some instances, the ancillary file is essential to a complete understanding and utilization of the data product. These ancillary files are referred to as the Ancillary Data Products. On the other hand, there are other ancillary files not relevant to utilization of the products. Here is a more complete definition of the terminology.
MISR's data products are summarized in the following table. There are many parameter files making up the MISR products, and in most instances these can be ordered individually. Table B is designed to introduce the ways in which the many constituent parts of the products are grouped as high-level, logical collections. The Product ID column refers to the designations given in the EOS Data Products Handbook. Note that the final three products listed in this table are Ancillary Products, as defined above.
Note that Table B is not necessarily a breakdown of MISR products for ordering purposes. That topic is addressed in Section 2.5.
| Product ID | Product level and description | Parameter summary and associated ancillary products |
|---|---|---|
| MIS-01C | 1A - Reformatted Annotated Products for calibration and mechanism data categories: This contains raw MISR data that have been decommutated and annotated (e.g., with time information). These data are not used as input to any of the other MISR products. They are normally used only at the MISR SCF for calibration and instrument characterization purposes. | Standard products/parameters:
|
| MIS-01E | 1A - Reformatted Annotated Product for engineering data category: This contains raw MISR data that have been decommutated and annotated (e.g. with time information). These data are not used as input to any of the other MISR products. They are normally used only at the MISR SCF for instrument monitoring and characterization purposes. Note that the navigation data included here are raw data supplied on board the spacecraft, and do not include the corrections potentially applied to the navigation information obtained separately from the spacecraft and used at the DAAC in MISR data processing. | Standard products/parameters:
|
| MIS-01 | 1A - Reformatted Annotated Product for science data
category: This contains raw MISR data that have been
decommutated, reformatted (12-bit Level 0 data shifted to byte
boundaries, reversal of square-root encoding applied, and converted to 16
bits), and annotated (e.g., with time information). These data are used
by the Level 1B1 processing algorithm to generate calibrated radiances.
The science data output preserves the spatial sampling rate of the Level
0 raw MISR CCD science data.
CCD data are collected during routine science observations of the sunlit portion of the Earth. Each product represents one "granule" of data. A "granule" is defined to be the smallest unit of data required for MISR processing. Also, included in the Level 1A product will be pointers to calibration coefficient files provided for Level 1B processing. |
Standard products/parameters:
|
| MIS-02 | 1B1 - Radiometric Product: This contains spectral
radiances for all MISR channels (four spectral bands and nine cameras).
Each radiance value represents the incident radiance averaged over the
sensor's total band response. Processing includes both radiance scaling
and conditioning steps. Radiance scaling converts the Level 1A data from
digital counts to radiances, using coefficients derived in combination
with the On-Board Calibrator (OBC) and vicarious calibrations. The OBC
contains Spectralon calibration panels which are deployed monthly and
reflect sunlight into the cameras. The OBC detector standards then
measure this reflected light to provide the calibration. Vicarious field
campaigns are conducted less frequently but provide an independent
methodology useful for reducing systematic errors.
Radiance conditioning removes undesirable instrument effects. Image enhancement is provided by deconvolving the scene with the sensor's point-spread-function. Additionally, in-band scaling adjusts the reported radiances to correspond to a nominal band response profile. This frees the Level 2 software from the need to correct for detector element non-uniformities. No out-of-band correction is done for this product, nor are the data geometrically corrected or resampled. |
Standard products/parameters:
|
| MIS-03 | 1B2 - georectified radiance product (GRP): This consists
of parameters that have had geometric corrections applied and have been
projected to a Space Oblique Mercator (SOM) map grid. Included in this
product is the surface-projected TOA radiance which is the calibrated
radiance from the Level 1B1 data (MIS-02) that has had a geometric
correction applied to remove spacecraft position and pointing
knowledge errors as well as effects due to topography. The radiance is
then orthorectified on a reference ellipsoid at the surface. Also, part
of the GRP is the ellipsoid-projected TOA radiance which uses supplied
spacecraft position and pointing and is not corrected for topography, but
is resampled at the surface reference ellipsoid. In addition, geometric
parameters such as solar and view zenith and azimuth angles are included.
Resampling of MISR data at Level 1B2 is critical because the pushbroom images from the nine cameras are obtained at widely separated locations along the subspacecraft rack. However, derivation of geophysical products requires that the multiangle, multispectral radiances for any single ground target be coregistered. |
Standard products/parameters:
|
| MIS-04 | 2TC - Top-of-Atmosphere/Cloud (TOA/Cloud) Product: This consists of TOA radiation and cloud information including: finely-sampled (2.2 km) TOA albedo, coarsely-sampled TOA albedos projected to 30-km altitude (35.2 km), TOA bidirectional reflectance factor (BRF) at 2.2 km, and Reflecting Level Reference Altitude (RLRA) for 2.2-km regions, texture indices at 2.2 km, altitude-binned (high, middle, and low) and total cloud fractions at 17.6 km. The coarse TOA albedos provided will include a restrictive albedo, derived from the nine multiangle observations of a single region, and an expansive albedo which is calculated including contributions from surrounding regions, at the appropriate angles. Nadir cloud masks on 1.1-km centers for thick and high clouds will also be included. | Standard products/parameters:
|
| MIS-05 | 2AS - Aerosol/Surface product: This contains a variety of information on the Earth's atmosphere and surface. The aerosol data include tropospheric aerosol optical depth on 17.6-km centers, archived with a compositional model identifier and retrieval residuals, ancillary data including relative humidity (RH), ozone optical depth, stratospheric aerosol optical depth, and retrieval flags. The land surface data include hemispherical directional reflectance factor, bihemispherical reflectance (i.e., albedo), bidirectional reflectance factor, directional hemispherical reflectance, BRF model parameters, FPAR, and terrain-referenced view and illumination angles. Ocean data include water-leaving equivalent reflectance and phytoplankton pigment concentration. | Standard products/parameters:
|
| MIS-06 | 3 - Global Radiation Product: This Level 3 global gridded product is derived from parts of MIS-04, and will be developed post-launch. It contains a statistical summary of spectral top-of-atmosphere BRF for various subregion classifications; and a statistical summary of spectral expansive albedos for several sky classifications. | Gridded products are planned within a year after launch, but are not available yet. |
| MIS-07 | 3 - Global Cloud Product: This Level 3 global gridded product is derived from parts of MIS-04, and will be developed post-launch. It contains a statistical summary of altitude-binned scene classifiers. | Gridded products are planned within a year after launch, but are not available yet. |
| MIS-08 | 3 - Global Aerosol Product: This Level 3 global gridded product is derived from parts of MIS-05, and will be developed post-launch. It contains a statistical summary of column aerosol 555 nm optical depth, and a monthly aerosol compositional type frequency histogram. | Gridded products are planned within a year after launch, but are not available yet. |
| MIS-09 | 3 - Global Surface Product: This Level 3 global gridded product is derived from parts of MIS-05, and will be developed post-launch. It contains a statistical summary of directional hemispherical reflectance (DHR), photosynthetically active spectral region (DHR-PAR); a statistical summary of DHR, for near-infra-red band (DHR-NIR); a statistical summary of fractional absorbed photosynthetically active radiation (FPAR); a statistical summary of DHR-based normalized difference vegetation index (NDVI); and a statistical summary for land surface BRF model parameters, classified into six vegetated and one non-vegetated types. | Gridded products are planned within a year after launch, but are not available yet. |
| MIS-10 | 1B2 - Ancillary Geographic Product (AGP): This contains terrain data, generated from a high-resolution DEM, referenced to the WGS84 referenced ellipsoid and mapped onto an SOM grid. It is an archival product generated once preflight at the MISR SCF, but which can be distributed to the scientific community as an aid in interpreting MISR retrievals. The AGP is used as input to Level 1B2 and Level 2 processing. Its contents include latitude, longitude, scene elevation (average and standard deviation), topographic shadow and obscuration mask, surface-normal zenith angle, and a land/ocean/inland water/ephemeral water/coastline mask. All parameters are given on 1.1-km centers. | Standard products/parameters: Not applicable
Associated ancillary products: Not applicable |
| MIS-11 | 1B1 - Ancillary Radiometric Product (ARP): This contains coefficients and data variables which are used in the Level 1B1 processing. Updated ARP parameters include the sensor radiometric calibration coefficients, uncertainties in calibration, signal-to-noise ratios, pixel data quality indicators, and quality assessment threshold parameters. Static ARP parameters include spectral response parameters, point-spread-functions (PSF), field-of-view, passband-weighted solar irradiance values, and PAR integration weights. The ARP is regenerated periodically at the MISR SCF to update the instrument performance report. The ARP is used as input to Level 1B1 as well as Level 2 processing. | Standard products/parameters: Not applicable
Associated ancillary products: Not applicable |
| MIS-12 | 2AS - Ancillary Climatology Product (ACP): This is generated once, at the MISR SCF, with possible infrequent updates. It is used for interpolation of the aerosol data contained in MIS-05. The ACP contains the physical and optical properties that define common atmospheric aerosol types. The parameters reported in the ACP include an aerosol model identifier (name, number, and composition); a water activity identifier (hygroscopic or not, and if so, how hydrophilic); a partial shape identifier (spherical, polyhedral, or irregular); a grid of relative humidity values for which all optical properties have been calculated; particle size distribution parameters; particle density (volume-weighted for mixtures); complex index of refraction; scattering and extinction cross-section; single scattering albedo; scattering anisotropy parameter; and phase function. It also includes the definition of the aerosol mixtures to be used during generation of MIS-05, along with climatological likelihood parameters for these mixtures. | Standard products/parameters: Not applicable
Associated ancillary products: Not applicable |
MISR products are generated with the following granularity:
The swath-based products (described in the previous subsection) are very large. Many users will be interested only in those parts of the swath that cover their region of interest. Such users may not have the facilities to handle data available in only gigabyte-sized chunks. Because of this, subsetting of the swath-based products is planned. Subsetting is currently under development, and will be available for users within the first year of the mission.
Initially, subsetting will be for the HDF EOS grid format products (Level 1B2 and higher) on a block-by-block basis.
Users may wish to select particular parameters from a MISR product rather than obtaining the entire file. This capability is planned to be availableduring the first year of the mission.
The files that constitute MISR data products are referred to by file designators called Earth Science Data Types (ESDTs). A table of ESDTs is given just below in this document (Table C). The ESDT is the smallest breakdown of a product that can be ordered by the user, and most products consist of multiple ESDTs. Users will thus find themselves ordering a collection of MISR ESDTs. As the collections may not be automated, the following table gives an indication of how the ESDTs are grouped for typical collections. Individual users, especially those with specialist knowledge of MISR, may desire to order different collections from those shown here. However, the intention here is to present the most typical case.
It should be noted that while the Ancillary Products are part of various product collections, it is usually necessary to order the Ancillary Products only once because they change infrequently.
In Table C there are numbered columns for each typical product collection, which are:
| Collection No. (columns of Table C) |
Product ID | Description of collection |
|---|---|---|
| 1 | N/A | Level 0 data. Only specialist users or other MISR data processers are expected to required this. |
| 2 | MIS-01C | Level 1A calibration/mechanism data. Required only for MISR instrument calibration. |
| 3 | MIS-01E | Level 1A engineering data. |
| 4 | MIS-01 | Level 1A science data. This contains swath-based information with Global Mode and Local Mode data intermingled. These two modes are not separated until Level 1B1. |
| 5 | MIS-02 | Level 1B1 radiometric data, Global Mode swaths |
| 6 | MIS-02 | Level 1B1 radiometric data, Local Mode scenes |
| 7 | MIS-03 | Level 1B2 georectified imagery, Global Mode swaths |
| 8 | MIS-03 | Level 1B2 radiometric camera-by-camera cloud mask, Global Mode swaths |
| 9 | MIS-03 | Level 1B2 georectified imagery, Local Mode scene |
| 10 | MIS-03 | Level 1B2 radiometric camera-by-camera cloud mask, Local Mode scene |
| 11 | MIS-04 | Level 2TC stereo-derived cloud product |
| 12 | MIS-04 | Level 2TC albedo product |
| 13 | MIS-05 | Level 2AS aerosol/surface product |
| 14 | N/A | QA files |
| Data set designator (ESDT) | Data set long name | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MI2LME | MISR Level 1B2 Local Mode Ellipsoid Radiance Data | x | |||||||||||||
| MI2LMT | MISR Level 1B2 Local Mode Terrain Radiance Data | x | |||||||||||||
| MI1AC | MISR Level 1A Calibration Data | x | |||||||||||||
| MI1AENG1 | MISR Level 1A Engineering Data File Type 1 | x | |||||||||||||
| MI1AMOT | MISR Level 1A Motor Data | x | |||||||||||||
| MI1ANAV | MISR Level 1A Navigation Data | x | |||||||||||||
| MI1AOBC | MISR Level 1A On-Board Calibration Data | x | |||||||||||||
| MI1B1 | MISR Level 1B1 Radiance Data | x | |||||||||||||
| MI1B2E | MISR Level 1B2 Ellipsoid Data | x | |||||||||||||
| MI1B2T | MISR Level 1B2 Terrain Data | x | |||||||||||||
| MIB1LM | MISR Level 1B1 Local Mode Radiance Data | x | |||||||||||||
| MIL1A | MISR Level 1A CCD Science Data, all cameras | x | |||||||||||||
| MIL2ASAE | MISR Level 2 Aerosol parameters | x | |||||||||||||
| MIL2ASLS | MISR Level 2 Land Surface parameters | x | |||||||||||||
| MIL2ASOS | MISR Level 2 Ocean Surface parameters | x | |||||||||||||
| MIL2TCAL | MISR Level 2 Top of Atmosphere/Cloud Albedo parameters | x | |||||||||||||
| MIL2TCCL | MISR Level 2 Top of Atmosphere/Cloud Classifier parameters | x | |||||||||||||
| MIL2TCST | MISR Level 2 Top of Atmosphere/Cloud Stereo parameters | x | |||||||||||||
| MIANCAGP | MISR Ancillary Geometric Product | x | x | x | x | x | x | x | |||||||
| MIANCARP | MISR Ancillary Radiometric Product | x | x | ||||||||||||
| MIANACP | MISR Aerosol Climatology Product | x | |||||||||||||
| MIB2GEOP | MISR Geometric Parameters | x | x | x | x | x | x | x | |||||||
| MIRCCM | MISR Radiometric Camera-by-Camera Cloud Mask | x | |||||||||||||
| MISQA | MISR Quality Assessment Data | x |
The following table includes all the file designators (ESDTs) for the MISR standard products and ancillary products. Each product includes one or more of these files, as explained above.
| Designator (ESDT) | Data Set Long Name | Description | Format |
|---|---|---|---|
| MB2LME | MISR Level 1B2 Local Mode Ellipsoid Radiance Data | Ellipsoid projected TOA parameters for the single local mode scene, resampled to WGS84 ellipsoid. | HDF-EOS Grid |
| MB2LMT | MISR Level 1B2 Local Mode Terrain Radiance Data | Terrain-projected TOA radiance for the single local mode scene, resampled at the surface and topographically corrected. | HDF-EOS Grid |
| MI1AC | MISR Level 1A Calibration Data | Level 1A calibration data in DN. The data numbers have been commuted from 12-bit numbers to 16-bit, byte aligned half-words. | HDF-EOS Swath |
| MI1AENG1 | MISR Level 1A Engineering Data File Type 1 | Reformatted Annotated Level 1A product for the camera engineering data, which represents indicators of sampled measurements. | HDF |
| MI1AMOT | MISR Level 1A Motor Data | Output for the Level 1A Motor data. | HDF-EOS Swath |
| MI1ANAV | MISR Level 1A Navigation Data | Reformatted Annotated Level 1A Product for the Navigation Data, which contains samples of the Terra Platform position and attitude data. | HDF-EOS Swath |
| MI1AOBC | MISR Level 1A On-Board Calibration Data | Contains the output for the Level 1A On-Board Calibration Data. | HDF-EOS Swath |
| MI1B1 | MISR Level 1B1 Radiance Data | The Level 1B1 Product containing the DNs radiometrically-scaled to radiances with no geometric resampling. | HDF-EOS Swath |
| MI1B2E | MISR Level 1B2 Ellipsoid Data | Contains the ellipsoid projected TOA radiance, resampled to WGS84 ellipsoid corrected. | HDF-EOS Swath |
| MI1B2T | MISR Level 1B2 Terrain Data | Contains the terrain projected TOA radiance, resampled at the surface and topographically corrected. | HDF-EOS Swath |
| MIB1LM | MISR Level 1B1 Local Mode Radiance Data | Contains the DNs radiometrically scaled to radiances with no geometric resampling. | HDF-EOS Swath |
| MIL1A | MISR Level 1A CCD Science Data, all cameras | The Reformatted Annotated Level 1A product of the CCD science data. The data numbers (DN) have been commuted from 12-bit numbers to 16-bit byte aligned half-words. | HDF-EOS Swath |
| MIL2ASAE | MISR Level 2 Aerosol parameters | Contains aerosol optical depth and particle type, with associated atmospheric data. | HDF-EOS Grid |
| MIL2ASLS | MISR Level 2 Land Surface parameters | Contains information on load directional reflectance properties, albedos (spectral and PAR-integrated), FPAR, associated radiation parameters and terrain-referenced geometric parameters. | HDF-EOS Grid |
| MIL2ASOS | MISR Level 2 Ocean Surface parameters | Contains water-leaving equivalent reflectance and phytoplankton pigment concentration over tropical ocean. | HDF-EOS Grid |
| MIL2TCAL | MISR Level 2 Top of Atmosphere/Cloud Albedo parameters | Contains local, restrictive, and expansive albedo, with associated data. | HDF-EOS Grid |
| MIL2TCCL | MISR Level 2 Top of Atmosphere/Cloud Classifier parameters | Contains the Angular Signature Cloud Mask (ASCM), Regional Cloud Classifiers, Cloud Shadow Mask, and Topographic Shadow Mask, with associated data. | HDF-EOS Grid |
| MIL2TCST | MISR Level 2 Top of Atmosphere/Cloud Stereo parameters | Contains the Stereoscopically Derived Cloud Mask (SDCM), cloud winds, Reflecting Level Reference Altitude (RLRA), with associated data. | HDF-EOS Grid |
| MIANCAGP | MISR Ancillary Geometric Product | This file consists primarily of terrain data on a SOM Grid. It has 233 parts, corresponding to the 233 repeat orbits of the Terra spacecraft. | HDF-EOS Grid |
| MIANCARP | MISR Ancillary Radiometric Product | Comprises 4 files covering instrument characterization data, preflight calibration data, in-flight calibration data, and configuration parameters. | HDF-EOS Grid |
| MIANACP | MISR Aerosol Climatology Product | This product is 1) the microphysical and scattering characteristics of pure aerosol upon which routine retrievals are based; 2) mixtures of pure aerosol to be compared with MISR observations; and 3) likelihood value assigned to each mode geographically. | Binary |
| MIB2GEOP | MISR Geometric Parameters | Contains the geometric parameters which measure the sun and view angles at the reference ellipsoid. | HDF-EOS Grid |
| MIRCCM | MISR Radiometric Camera-by-Camera Cloud Mask | Contains the radiometric camera-by-camera cloud mask. It is used to determine whether a scene is classified as clear or cloudy. | HDF-EOS Grid |
| MISBR | MISR Browse Data | This is the browse data associated with a particular granule. (Although its purpose is as search tool in the on-line user interface, it is designed such that it can be a separately orderable product if so required by the user.) | HDF-EOS Grid |
| MISQA | MISR Quality Assessment Data | This is the quality information associated with a particular granule. | ASCII |
The following table includes all the file designators (ESDTs) for the ancillary data sets used in generating MISR standard products and ancillary products. As explained above, these files are not designed specifically for distribution but may be available on request except for a few cases that are restricted.
| Designator (ESDT) | Data Set Long Name | Description | Format |
|---|---|---|---|
| MIRFOI | MISR Reference Orbit Images | Unresampled MISR Imagery (Radiometric Product - L1B1) associated with the Projection Parameters. An ROI is a composite of several orbit passes in order to reduce the cloud cover. | HDF-EOS Swath |
| MIANCSSC | MISR Cloud Screening Surface Classification | Contains the MISR Cloud Screening Classification Data Set used in Level 2 processing. | HDF-EOS Grid |
| MIANSMT | MISR Simulated MISR Ancillary Transfer | Produced by the MISR SCF and shipped to the DAAC for generating Level 2 products. | HDF-EOS Grid |
| MIANTASC | MISR Terrestrial Atmosphere and Surface Climatology | Produced by the MISR SCF and shipped to the DAAC for generating Level 2 products. | HDF-EOS Grid |
| MIANTOAC | MISR Tropical Ocean Atmosphere Correction | Data set used as an ancillary input file to the Level 2 processing. | Binary |
| MIASH | MISR Angular Signature Histogram | Data set used in Level 2 processing. | HDF-EOS Grid |
| MIAST1 | MISR Angular Signature Threshold - Biweekly File | Used in Level 2 processing. Biweekly updated file. | Binary |
| MIAST2 | MISR Angular Signature Threshold - Seasonal File | Used in Level 2 processing. Seasonal updated file. | Binary |
| MIAST3 | MISR Angular Signature Threshold - Static File | Used in Level 2 processing. Static file. | Binary |
| MIANAZM | MISR Azimuthal Model Data Set | Contains the azimuthal model data set. | HDF-EOS Grid |
| MIANLDBM | MISR Ancillary Land Biome Data Set | Consists of a Land Surface Classification by Biome Types. | HDF-EOS Grid |
| MIANPP | MISR Projection Parameters | The image coordinates which relate SOM map projection grid centers (275m resolution) to the Reference Orbit Imagery. (This data is restricted.) | HDF-EOS Grid |
| MIANRCCH | MISR Radiometric Camera-by-Camera Histogram Data Set | Contains histogram hits associated with a particular orbit and camera to be added to the Radiometric Camera-by-Camera Histogram Data Set. | HDF-EOS Grid |
| MICNFG | MISR Configuration File | Configuration constants for all PGEs. | ASCII |
| MIRCCT | MISR Radiometric Camera-by-Camera Threshold Data Set File | Contains the radiometric camera-by-camera threshold data set. | Binary |
| MISANCGM | MISR Camera Geometric Model | A parametric model describing the internal geometry of the nine cameras relative to the spacecraft frame of reference. | ASCII |
|
For those who are interested in or need to know greater detail, here are two diagrams that give graphical illustrations of the complete associations between individual MISR standard products and the respective ancillary data sets and ancillary data products. Select the left hand thumbnail to see a full-sized diagram of the Level 1 file relationships. Select the right-hand thumbnail to see a full-sized diagram of the Level 2 file relationships. Note that there is no illustration for Level 3 as these products are still under development. |
|
Data will be made available to the user via 8mm tape or by FTP (see Data Access section below).
There is no proprietary status for the data sets currently on-line at the Langley DAAC, except for certain restricted data sets of non-NASA origin, as indicated above.
The MISR data is accessible by contacting the NASA Langley DAAC.
The EOS Data Gateway system will serve as the main search and order service for the EOSDIS Core System (ECS) which is being built to accommodate the tremendous amount of data expected from the new series of EOS instruments.
The EOS Gateway allows users to search science data holdings, retrieve high-level descriptions of data sets and detailed descriptions of the data inventory, view browse images, and place orders for data products.
Search methods are available to aid the user in obtaining the desired data. A general search is made by specifying geographic areas of interest along with either geophysical parameter, data set name, or sensor name. Three different search types provide increasingly detailed information about the science data available through the system. A directory search provides summary information about EOSDIS data sets. This type of search accesses the Global Change Master Directory (GCMD), a multidisciplinary database of information about Earth science data. A guide search provides detailed descriptions about data sets, data sources, instruments, projects, and data centers; it may include algorithm descriptions and calibration information. The inventory search gives descriptions of specific observations or collections of observations of data (granules) that are available from a data center.
The Gateway system includes a coverage map which is a graphical representation of the geographic coverage of selected data observations (data granules).
A browse function is also included which allows the user to view data (possibly reduced in resolution) as an aid for selecting many of the products available from the data centers. Such data may be viewed in the EOS Data Gateway interface or retrieved via File Transfer Protocol (FTP).
The order function allows the user to select the desired data processing options and media, and allows the user to specify contact, billing, and shipping addresses.
Langley Atmospheric Science Data Center
NASA Langley Research Center
Currently, there is no cost associated with this data.
Please direct inquiries to NASA Langley User Services: larc@eos.nasa.gov
Please direct inquiries to NASA Langley User Services: larc@eos.nasa.gov
Here are several references to papers that give an instrument overview and an introduction to the aerosol and surface retrievals.
Diner, D.J., J.C. Beckert, T.H. Reilly, C.J. Bruegge, J.E. Conel, R. Kahn, J.V. Martonchik, T.P. Ackerman, R. Davies, S.A.W. Gerstl, H.R. Gordon, J-P. Muller, R.B. Myneni, R.J. Sellers, B. Pinty, and M.M. Verstraete (1988). Multiangle Imaging SpectroRadiometer (MISR) description and experiment overview. IEEE Trans. Geosci. Rem. Sens., Vol. 36, pp 1072-1087.
Martonchik, J.V., D.J. Diner, R. Kahn, T.P. Ackerman, M.M. Verstraete, B. Pinty, and H.R. Gordon (1988). Techniques for the retrieval of aerosol properties over land and ocean using multi-angle imaging, IEEE Trans. Geosci. Rem. Sens., VOl. 36, pp 1212-1227.
Martonchik, J.V., D.J. Diner, B. Pinty, M.M. Verstraete, R.B. Myneni, Yu. Knyazikhin, and H.R. Gordon (1988). Determination of land and ocean reflectance, radiative, and biophysical properties using multi-angle imaging, IEEE Trans. Teosci. Rem. Sens., Vol. 36, pp 1266-1281.
A complete list of references can be found on the MISR web site's Publications page.
See the EOSDIS glossary.
See also the EOSDIS acronyms list.
