Preflight test results of the ASTER TIR flight model

The thermal infrared radiometer (TIR) is one of three radiometer on advanced spaceborne thermal emission and reflection radiometer (ASTER) which will be aboard NASA's EOS- AM1 polar orbiting platform to be launched in 1998. TIR will be used for precision observations in various fields, including solid earth science, resources exploration, cloud science, hydrology, and ocean science. Measurements by TIR will be made of surface temperature and emissivity, volcano activity, cloud top temperature, cloud structure, evapotranspiration, and ocean temperature. Manufacturing and testing of the proto-flight model (PFM) has already been done. This paper gives an overview of the proto-flight data based on the proto-flight test (PFT) for the TIR. Major performances are as follows: (1) modulation transfer function (MTF) is larger than 0.25 at Nyquist frequency. (2) Noise equivalent temperature difference (NETD or NE(Delta) T) is less than 0.3 K for 300 K target. (3) Dynamic range is between 200 K and 370 K. The standard blackbody with temperature between 100 K and 400 K was used in vacuum test for NETD, dynamic range and linearity. Also, the collimater was used for MTF and so on. Test has done well and results satisfied with all specifications.