Carbon monoxide mixing ratio inference from gas filter radiometer data.

A new algorithm has been developed which permits, for the first time, real-time data reduction of nadir measurements taken with a gas-filter correlation radiometer to determine tropospheric carbon-monoxide concentrations. The algorithm significantly reduces the complexity of the equations to be solved while providing accuracy comparable to line-by-line calculations. The method is based on a regression analysis technique using a truncated power series representation of the primary instrument output signals to infer directly a weighted average of trace gas concentration. The results produced by a microcomputer-based implementation of this technique are compared with those produced by the more rigorous line-by-line methods. This algorithm has been used in the reduction of MAPS Shuttle and aircraft data.