Radiometric Calibration of ASTER Data

抄録

Preflight and in-flight radiometric calibration plans are described for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which is a high spatial resolution imaging spectro-radiometer. It is designed for the remote sensing from orbit of land, lakes, coastal and ocean surfaces, and clouds, and is expected to be launched in 1998 on NASA's EOS AM-1 Spacecraft. ASTER comprises three subsystems which acquire images in three separate spectral regions: the visible and near infrared (VNIR), the shortwave infrared (SWIR), and the thermal infrared (TIR). The absolute radiometric accuracy is required to be better than 4% for VNIR and SWIR radiance measurements, and 1 K to 3 K, depending on the temperature region from 200 K to 370 K, for TIR temperature measurements.
ASTER will be calibrated in the laboratory by reference to sources traceable to NRLM and NIST standards and through the use of transfer radiometers. Partial aperture on-board calibration systems will be used in the solar-reflective range and an on-board full aperture blackbody source will be used in the infrared. An important independent source of calibration data will be provided through the in-flight radiometric calibration of ASTER by reference to well-characterized scenes.
This paper very briefly describes the calibration specifications for ASTER, the on-board calibration systems, the preflight and in-flight calibration procedures to be used, and suggests a method for combining the results of the various calibration inputs.