HR: 14:25h
AN: H22E-03    [PDF]
TI: On-Orbit Calibration of AMSR-E
AU: * Wentz, F J
EM: wentz@remss.com
AF: Remote Sensing Systems, 438 First Street, Santa Rosa, CA 95401 United States
AU: Ashcroft, P J
EM: Ashcroft@remss.com
AF: Remote Sensing Systems, 438 First Street, Santa Rosa, CA 95401 United States
AU: Gentemann, C L
EM: gentemann@remss.com
AF: Remote Sensing Systems, 438 First Street, Santa Rosa, CA 95401 United States
AB: AMSR-E has an on-board 2-point calibration system that continuously compensates for variations in the radiometers gain and noise temperature. The two vital components of this calibration system are the cold mirror and the hot reference load. The cold mirror provides a clear view of deep space, which is at a known temperature of 2.7 K. The hot reference load acts as a black-body emitter and its temperature is measured by precision thermistors. Unfortunately, the design of the AMSR-E hot load is flawed. During the course of an orbit, large thermal gradients develop within the hot load due to solar heating making it difficult to determine the average effective temperature from the thermistor readings. A solution to the hot load problem has been found. Using the existing network of satellite radiometers, we developed a technique for estimating the effective temperature of the AMSR-E hot load. Remote Sensing Systems maintains a real-time database containing daily observations from U.S. operational satellites. These satellite observations are collocated in time and space with the AMSR-E observations. The collocated observations are then processed by a radiative transfer model that computes the intensity of radiation entering the AMSR-E feedhorns. In essence, this process provides an earth-target calibration point. A 2-point linear extrapolation based on the cold mirror and earth-target calibration points yields the desired quantity: the effective temperature for the hot load. The effective temperature is then correlated with variations in the hot load thermistors, and an expression is found that gives the effective temperature as a function of the thermistor array.
UR: http://www.remss.com
DE: 4275 Remote sensing and electromagnetic processes (0689)
DE: 6969 Remote sensing
SC: Hydrology [H]
MN: 2003 Fall Meeting