What an amazing and useful dataset. Satellites do not measure temperature directly. They measure radiances in various wavelength bands, from which temperature may be **inferred**. The resulting temperature profiles depend on details of the methods that are used to obtain temperatures from radiances. As a result, different groups that have analyzed the satellite data have obtained different temperature data (see Microwave Sounding Unit temperature measurements). Among these groups are Remote Sensing Systems (RSS) and the University of Alabama in Huntsville (UAH). The satellite series is not fully homogeneous - it is constructed from a series of satellites starting with the 1978 TIROS-N, where different satellites had similar but not identical instrumentation. The sensors deteriorate over time, and **corrections** are necessary for satellite drift and orbital decay. Particularly large differences between **reconstructed** temperature series occur at the few times when there is little temporal overlap between successive satellites, making intercalibration difficult.