Science validation of the OMI Level 0-1b processor

摘要

With the Dutch-Finnish Ozone Monitoring Instrument (OMI) hardware mounted on NASA's EOS-AURA spacecraft and the AURA planned for launch in 2004, we are working to prepare for flight. An important step in this preparation is the science validation of the software converting the instrument bit stream into (ir-) radiances, the 0-1b processor. The paper contains a description of the main elements of the 0-1b processor and it discusses the methods we have chosen for the validation process. Next it we discuss the outcomes of the various tests and thereby reveal the criticality of each of the algorithms. The algorithms we are dealing with are CCD detector corrections, algorithms to implement radiometric sensitivity of the instrument, stray light correction and the Fraunhofer lines based wavelength calibration algorithm. Because of the CCD, the stray light correction algorithm is two dimensional and the wavelength calibration algorithm is complex due to the fact that we aim at an extreme accuracy of 1/100 pixel or 2.10-3 nm. The validation partly makes use of the OMI Instrument Response Simulator and partly of on-ground performance and calibration measurement data.