Comparison of Microwave and Infrared Land Surface Temperature Products Over the

Abstract—Two different remotely sensed land surface tem-perature (Ts) products are compared with in situ observations from the National Airborne Field Experiment research site in the western part of the Murrumbidgee catchment, Australia. The remotely sensed Ts products are retrieved from the following: 1) Ka-band passive microwave (MW) observations using several of space-based MW radiometers and 2) thermal infrared observa-tions from the Moderate Resolution Imaging Spectroradiometer (MODIS) on two satellite platforms. Both methods show similar accuracy when compared to ground observations, although the dynamic range and mean differ significantly. However, a direct comparison of the two products at the same overpass time reveals a strikingly constant relation, with a standard error of∼4 K. The results of this study indicate that a merged Ts product of both MODIS and MW observations is feasible and would decrease the amount of data gaps and increase the sampling frequency for this region to 12 observations a day. Index Terms—Land surface temperature (Ts), microwave (MW) radiometry, National Airborne Field Experiment (NAFE), thermal infrared (TIR)