Geometry-Related ATMS Signal Pattern Analyses

When integrating data from multiple satellites, a basic assumption is that the observations from
different instruments have the same physical representation. However, a satellite observation is the
observed physical observation with an additional instrument response. The instrument response
introduces non-physical information on to the observation creating inconsistencies between integrated
satellite datasets from different sensors. It is important to quantity and understand this effect. The
Advanced Technology Microwave Sounder (ATMS) is a cross-track scanner with 22 channels on the JPSS
polar orbiting satellite series. ATMS microwave observations provide atmospheric information in both
clear and cloudy conditions and provide continuity with those earlier observations from the heritage
AMSU-A/B and MHS instruments on the POES and MetOp series satellites. The along-scan asymmetrical
patterns have been characterized using real data, but there is no well-defined formulation and analysis
of the uncertainty this creates. Using the general Stokes antenna temperature formulation, the
expression for the modified Stokes vector of the ATMS antenna temperature is derived. The ATMS plane
reflector emissivity effect and antenna pattern are included. The contribution factors for the ATMS
asymmetrical scanning are analyzed and discussed. The goal of this research is to provide a better
understanding of uncertainty in collocated ATMS data.