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Appendix F: NASA Earth-Observing Instruments 133

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134 Technology for Small Spacecraft NASA EARTH-OBSERVING INSTRUMENTS InstrumentCapabilities l\4ass Power Status Developer (kg) (W) Near-Term Instruments (up to 200S) Active Cavity Radiometer Will extend the long-term solar 39 40 Under JPL Irradiance Monitor luminosity data base, providing a development long-term precision of 5 parts per million per year in its monitoring of the variability of total solar irradiance. Atmospheric Infrared High-resolution, high-precision 140 240 Phase C/D Loral Sounder sounder employing 2,300 (since 1991) simultaneous spectral channels covering the range from 0.4 to 15.4 micrometers. Advanced Microwave Passive microwave radiometer with 100 125 Under Aerojet Sounding Unit 21 channels from 23.8 GHz to 89 development General GHz. Microwave Humidity Passive microwave radiometer 66 190 Phase B Matra Marcon Sounder tailored to the requirement for and British humidity profiling. The Microwave Aerospace and Humidity Sounder has 5 channels in will be the region from 89 GHz to 183 provided by GHz. Eumetsat Advanced Spaceborne Imaging radiometer to provide high 400 674 Under NEC with Thermal Emission and spatial resolution and radiometrically development MELCO and Reflection Radiometer precise images of the land surface, Fujitsu water, ice, and clouds. The instrument uses a relatively narrow, 60-km swath that can be pointed cross-track + 8.5 in the mid- and long-wave infrared and +24 in the visible and near infrared. The spectral coverage extends from 0.5 to 12 micrometers. The maximum spatial resolution is 15 meters in the visible and near infrared. Doppler Orbitography and Dual Doppler receiver tracking 44 17.6 Under Dessault Radiopositioning system for orbit determination. development Electronique Integrated by Satellite 11

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Appendix F 135 NASA EARTH-OBSERVING INSTRUMENTS (Continued) ~ . Instrument Capabilities Mass Power (kg) (W) Near-Term Instruments (up to 2005) Status Developer Clouds and Earth's Radiant Energy System Ocean Color Instrument Earth Observing Scanning Polarimeter Lightning Imaging Sensor Will provide an accurate, self- consistent cloud and radiation data base. Clouds and Earth's Radiant Energy System employs two broadband scanning radiometers, with each radiometer having three channels. The first channel is a total radiance channel extending from 0.3 to beyond 50 micrometers. The second is a shortwave channel extending from 0.3 to 5 micrometers. The third channel covers the longwave region from 8 to 12 micrometers. High radiometric precision data in eight spectral bands extending from 402 nanometers to 885 nanometers. Daily global coverage is provided with a maximum spatial resolution of 1. 1 kilometers. Will provide global maps of cloud and aerosol properties. The cloud properties will include optical thickness, particle size, liquid/ice phase, and cloud-top pressure. The aerosol measurements will include global distribution and optical thickness in the troposphere and stratosphere. Earth observing scanning polarimeter measures radiance and the degree of linear polarization in 12 spectral bands from 0.41 to 2.25 micrometers. Designed to investigate the global incidence of lightning, to correlate the data with rainfall, and to employ the data in investigating the relationship of lightning to the global electric circuit. A 128 x 128 charge- coupled device array locates lightning flashes within 5 kilometers over a 600 x 600 km field-of-view. 90 171 Phase C/D TRW 80 90 Data not Data not available available 19 22 Phase C/D in Data not 1 994 available 20 33 Under Marshall Space development Flight Center

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136 Technology for Small Spacecraft NASA EARTH-OBSERVING INSI1?tUMENTS (Continued) InstrumentCapabilities Mass Power Status Developer (kg) (W) Near-Term Instruments (up to 2005) Geoscience Laser Focuses solely on the laser altimetry 125 175 Phase B Data not Altimeter mission, and will enable 10-em completed available precision with a 70-meter surface Phase C/D in footprint. 1 995 High-Resolution Dynamics Employs 21 channels at infrared 150 230 Phase C/D in Loral and Limb Sounder wavelengths from 6 to 18 1991 Matra-Mareoni micrometers in a limb-scanning Space radiometer that will sound the upper troposphere, stratosphere, and mesosphere to measure temperature, concentrations of aerosols, locations of polar stratospheric clouds and cloud tops, and the concentrations of key molecules. The molecules to be studied include 03, H2O, CH4, N2O, NO2, HNO3, N2O5, CFC,,, and CFC,2. Multifrequeney Imaging Passive microwave radiometer that 223 200 Phase B Alenia Microwave Radiometer measures precipitation rate, cloud Phase C/D in water content, atmospheric water 1995 vapor, sea-surface roughness, sea surfaee temperature, global ice and snow cover, and soil moisture. It is an extension of technology currently being flown on the Defense Meteorological Satellite Program, namely the Special Sensor Microwave/Imager. Multi-frequency imaging microwave radiometer operates at six frequencies from 6.8 to 90 GHz, has a nominal 0.5-Kelvin radiometric stability with approximately a 1-Kelvin accuracy. Moderate-Resolution General purpose spectrometer end 250 275 Phase C/D in Santa Barbara Imaging imager to examine a wide variety of 1991 Research Speetro-Radiometer biological and physical processes. Its Center spatial resolution will be from 250 to 1,000 meters at nadir and its spatial coverage will extend from 0.4 to 15 micrometers in 36 discrete bands.

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Apperldix F NASA EARTH-OBSERV~G INSTRUMENTS (Continued) 137 InstrumentCapabilities l\'Iass Power Status Developer (kg) (W) Near-Term Instruments (up to 2005) Multi-AngleImaging Will provide top-of-the-atmosphere, 106 107 Phase C/D in JPL Spectro-Radiometer cloud, and surface angular 1991 reflectance properties. The time between multidirectional observations of each scene will be within a few minutes, ensuring that the observations are done with essentially the same atmospheric conditions. Nine separate charge coupled device pushbroom cameras observe the earth at nine angles at nadir and fore and aft of the spacecraft's track. Images are made in four spectral bands from 0.443 to 0.865 micrometers. The instrument swathwidth is 356 km and the ground sampling is commendable to be 240, 480, 960, or 1,920 meters. Microwave Limb Sounder Will employ a microwave limb 500 540 Under JPL sounding radiometer-spectrometer to development study the chemistry of the lower stratosphere and upper troposphere for the effects on changes in greenhouse and related gases (H2O, 03, C1O, HCL, OH, HNO3, NO, N2O, HE, and CO), radiative forcing of climate change, and ozone depletion. It will also examine the ozone chemistry of the middle and upper stratosphere. The microwave limb sounder will measure SO2 and other gases in volcanic plumes. It contains five heterodyne radiometers at 215 GHz, 440 GHz, 640 GHz, 1.2 THz, and 2.5 THz. Solar Stellar Irradiance Four-channelprecision ultraviolet 99.5 42 Phase C/D start National Comparison Experiment II spectrometer that provides daily date has not Center for measurements of the full-disk solar been set Atmospheric ultraviolet irradiance with calibration Research maintained by comparison of the signal with that from bright, early type stars. The spectral coverage of the instrument is from 5 to 440 nanometers.

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138 Technology for Small Spacecraft NASA EARTH-OBSERVING INSTRUMENTS (Continued) Instrument Capabilities Mass Power (kg) (W) Status Developer Near-Term Instruments (up to 2005) . . Measurements of Pollution in the Troposphere NASA Scatterometer II Stratospheric Aerosol and Gas Experiment III Will measure emitted and reflected infrared radiance in the atmospheric column. This will permit the determination of tropospheric CO profiles and total column concentrations of CH4. Measurements of Pollution in the Troposphere is a correlation spectrometer that employs an on- board pressure-modulated cell containing a sample of the gas to be measured. Will acquire all-weather measurements of near-surface vector winds over the ice-free oceans. The instrument produces two 600- kilometer swaths separated by a 325- kilometer nadir gap. It has a spatial resolution of 25 kilometers. Stratospheric Aerosol and Gas Experiment III will improve upon global profiles of atmospheric aerosols, ozone, water vapor, NO2, NO3, OCIO, temperature, and pressure in the mesosphere, stratosphere, and troposphere. The instrument will also characterize upper tropospheric and stratospheric clouds and extend the solar occultation data sets begun in 1978. The instrument uses solar and lunar occultations to measure aerosols and gases in the atmosphere, measuring extinction of transmitted energy in the spectral region from 0.29 to 1.55 micrometers. 120 20~) Under Canadian development Space Agency 270 290 Phase C/D start JPL date has not been set 40 60 Under Ball Aerospace development

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Appendix F 139 NASA EARTH-OBSERVING INSTRUMENTS (Continued) Instrument Capabilities Mass Power Status Developer (kg) (W) Near-Term Instruments (up to 2005) Tropospheric Emission Provides very high spectral 340 460 Data not Data not Spectrometer resolution measurements from 2.3 to available available 15.4 micrometers using an infrared imaging Fourier transform technique. Its objective is to produce global three-dimensional profiles of nearly all infrared active gases from the Earth's surface to the lower stratosphere. Mid-Term Sensors and Beyond 2005 Earth-Observing System All-weather, day-night, high-spatial- 1,300 5,800 N/A N/A Synthetic Aperture Radar resolution imagery. It offers the means to study dynamic phenomena (e.g., flooding) in all seasons and at all latitudes, as well as in areas such as the tropics where cloud cover is prevalent. In addition, synthetic aperture radar offers the capability to measure soil, snow, and canopy moisture. High ResolutionImaging Spectral coveragafrom 0.4 to 2.45 450 600 N/A N/A Spectrometer micrometers in 192 bands with 10 nanometer resolution. It provides a 30-meter spatial resolution at nadir and a 24 km swathwidth. Laser Atmospheric Wind Employs a Doppler lidar system that 800 2,200 N/A N/A Sounder is to make direct wind measurements in the troposphere. . SOURCE: Asrar and Dokken, 1993.

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