Here is one of the first GPS-RO temperature profiles ever recorded, acquired by GPS/MET on April 5, 1995 -- just one day after launch. The RO profile is compared against a nearby weather balloon (radiosonde) profile and a weather model estimate from the European Center for Medium-range Weather Forecasts (ECMWF). Note that the model profile cannot capture the detail of the other two.  (GPS retrieval by JPL, 1995)