MAPS Level 2
Entry Title: Measurement of Air Pollution from Satellites (MAPS) Office of Space and Terrestrial Applications - 3 (OSTA3) Carbon Monoxide Second by Second data
Entry ID: MAPS_OSTA3_COSEC_HDF_1
Tropospheric Composition
Description
MAPS Overview The MAPS experiment measures the global distribution of carbon monoxide (CO) mixing ratios in the free troposphere. Because of MAPS' previous flights on board the Space Shuttle, Earth system scientists now know that carbon monoxide concentrations in the troposphere are highly variable around the planet, and that widespread burning in the South American Amazon Basin and southern cerrados, the African savannahs,and the Australian grasslands and ranches are major sources of carbon monoxide in the southern hemisphere and tropical troposphere.InstrumentThe MAPS instrument is based on a technique called gas filter radiometry. Thermal energy from the Earth passes through the atmosphere and enters the viewport of the downlooking MAPS instrument. Carbon monoxide and nitrous oxide (N2O) in the atmosphere produce unique absorption lines in the transmitted energy. The energy which enters the MAPS instrument is split into three beams. One beam passes through a cell containing CO and falls onto a detector. This CO gas cell acts as a filter for the effects of CO present in the middle troposphere. A second beam falls directly onto a detector without passing through any gas filter. The difference in the voltage of the signals from these two detectors can be used to determine the amount of CO present in the atmosphere at an altitude of 7-8 km. A third beam of the incident energy passes through a cell containing N2O and falls onto a detector. This N2O gas cell acts as a filter for the effects of N2O present in the atmosphere. The global distribution of N2O is well known, so the N2O signal can be used to detect the presence of clouds in the field of view and to correct the simultaneous CO measurement for systematic errors in the data.The data that are available from MAPS OSTA3 include a 5 by 5 degree gridded box (MAPS_OSTA3_5X5_HDF) and a second by second data product (MAPS_OSTA3_COSEC_HDF). These data sets are available from the Langley DAAC.
Resources and Documentation
PROFESSIONAL HOME PAGE
VIEW RELATED INFORMATION
- How to cite ASDC data
DATA CITATION POLICY
- ASDC Data and Information for MAPS
- MAPS Second by Second Langley DAAC Data Set Document
GENERAL DOCUMENTATION
- NASA Langley Factsheet for MAPS
MICRO ARTICLE
- Sample read program for MAPS_SRL1_COSEC_HDF, MAPS_SRL2_COSEC_HDF, and MAPS_OSTA3_COSEC_HDF - Direct File Download (.c)
- Script that compiles the C code necessary to read the following MAPS HDF data files: 1) MAPS_OSTA3_COSEC_HDF, 2) MAPS_SRL1_COSEC_HDF, 3) MAPS_SRL2_COSEC_HDF
SCIENCE DATA PRODUCT SOFTWARE DOCUMENTATION
Keywords
From GCMD Science Keywords:
- CARBON MONOXIDE
- NITROUS OXIDE > NITROGEN COMPOUNDS
- Large-Scale Biosphere-Atmosphere (LBA)
Data Distribution
File Format(s):
HDF4
Note: "Get Dataset" is a link to our recommended order method. The down arrow will show you additional options.
Spatial Information
Spatial Coverage Type: Horizontal
Coordinate System: Cartesian
Granule Spatial Representation: Geodetic
Locations
TROPOSPHERE
Temporal Information
Temporal Coverage: 1984-10-06 - 1984-10-13
Temporal Resolution: 1 second