Low-Level Processing of Passive Hyperspectral Microwave Measurements from Hisrams

The High Spectral Resolution Airborne Microwave Sounder (HiSRAMS) is a pair of proof-of-concept hyperspectral radiometers. One probe targets the 183 GHz water vapour band, while the other targets the 54 GHz oxygen band. Its data can be used to infer temperature and humidity profiles in the atmosphere for the benefit of numerical weather prediction. A series of artifacts are present in HiSRAMS data, each of which must be corrected in the raw signal or in the calibrated spectra. This work presents the challenges of and the methodology applied to the Level 0 processing of HiSRAMS data, including (a) detection and removal of radio-frequency interference, (b) image rejection, and (c) spectral resampling.