Intercomparison of AirMISR, CAR, and MISR Observations of Bidirectional Reflectance Factor, Mongu Tower, Zambia, During SAFARI 2000 Dry Season Campaign

The SAFARI 2000 Dry Season Campaign was carried out across southern Africa in August and September, 2000. The campaign had as goals: (1) study of aerosol sources, transport, modification, and deposition, (2) the impact of atmospheric constituents on African ecosystems, (3) the field measurement of surface reflectance and atmospheric aerosol properties, and (4) measurement of atmospheric and surface properties from MISR and other instruments aboard TERRA. The validation of space platform measurements would permit extension in space and time of the platform measurements. An integral component was making coordinated observations by surface and aircraft measurements. The present work focussed on validation of bidirectional reflectance factor (BRF) by the Multiangle Imaging SpectroRadiometer (MISR, the TERRA Platform), the Cloud Absorption Radiometer (CAR, GSFC, CV-580 Aircraft, University of Washington), and AirMISR (ER-2, NASA DFRC, JPL). Numerous sorties were flown by both the ER-2 (20 km altitude) and CV-580 (altitude ~1 km). A single coincident flight covering miombo woodland was achieved at Mongu Tower (-15.438 deg lat, 23.253 deg long) on Sept 06, 2000 under cloud-free but hazy conditions. BRF intrcomparisons are under development between MISR (Sept 10, 2000 overpass) AirMISR and CAR. The value of CAR is that a bidirectional reflectance is measured rapidly over all azimuths and can be used to compare BRF at other azimuths of observation such as those of AirMISR and MISR. Twenty three BRF recoveries from MISR have subsequently been made covering the interval Sept. 06, 2000 - July 25, 2001. These are under screening for residual clouds to seek seasonal or other reflectance variations present. Such MISR time series provide basis for study of system impacts on a multiyear basis, a principal goal of the SAFARI 2000 experiment.