Instrument sensitivity and error analysis for the remote sensing of tropospheric carbon monoxide by MOPITT

Measurement of Pollution in the Troposphere (MOPITT) is an eight-channel ga s correlation radiometer selected for the Earth Observing System AM-1 platf orm to be launched in 1999. Its primary objectives are the measurement of t ropospheric carbon monoxide (CO) and methane (CH4). In this paper, the sens itivities of instrument signals and CO retrieval errors to various instrume nt parameters, especially the gas cell pressure and temperature variations, instrument radiometric noise, and ancillary data errors (such as atmospher ic temperature and water vapor profile errors), are presented and discussed . In the MOPITT pressure modulator sell pressure sensitivity study, the ins trument calibration process is considered, which leads to the relaxation of previous stringent requirements on the accuracy of in-orbit cell pressure monitoring. The approach of MOPITT CO retrieval error analysis is described , and the error analysis results are compared with retrieval simulation sta tistics. The error analysis results indicate that tropospheric CO distribut ions can be retrieved with a precision of 10% for most of the troposphere.