Spectrometers
MAPS
The Measurement of Air Pollution from satellite (MAPS) instrument was flown with the Space Radar Laboratory-1 on the Space Shuttle "Endeavor" (STS-59) launched April 9, 1994. The objectives of the MAPS instrument were to measure the global distribution of carbon monoxide (CO) in the troposphere and its role in global tropospheric chemistry. The MAPS instrument, flown on two previous Shuttle flights (1981 and 1984), is a precursor to EOS-era instruments. The MAPS instrument was able to detect CO and nitrous oxide using gas filter radiometry to measure the IR absorption wavelength band in the atmosphere for these trace gases (4.67 micrometer). The MAPS instrument viewed the Earth simultaneously through three cells, one cell filled with CO, one filled with nitrous oxide, and one filled with helium (which does not absorb at these wavelengths). The difference in the energy received as seen through cell pairs enabled researchers to derive the amount of CO and nitrous oxide in the atmosphere. The nitrous oxide measurements provided a method for automatically rejecting cloud-contaminated observations of CO. The MAPS instrument consisted of the optical subassembly, which contained the optical elements, blackbodies, gas cells, detectors, preamplifiers, and calibration unit; the electronics subassembly, which housed the signal processing and control circuits; the flight tape recorder subassembly; and the aerial camera subassembly, which provided correlative cloud cover photos during the daylight portion of the flight. MAPS is expected to fly with the SRL again in 1994 and 1995. Information on the MAPS sensor, visit the STS-59 site at "http://science.ksc.nasa.gov/shuttle/missions/sts-59/mission-sts-59.html" Information about the Space Radar Laboratory can be found on the NASA JPL WWW Home Page: "http://www.jpl.nasa.gov" Personnel: Louis Caudill (NASA HQ) - Program Manager Dr. Michael Kurylo (NASA HQ) - Program Scientist Dr. Henry G. Reichle, Jr. (NASA LaRC) - Principal Investigator John Fedors (NASA LaRC) - Project Manager