Identifying and resolving a calibration issue with GMI

A calibration issue with the Global Precipitation Measurement (GPM) Microwave Imager (GMI) has been identified and resolved using an extended version of the vicarious warm calibration method in combination with the vicarious cold calibration method. With this extended warm-scene method, we found along-scan anomalies in GMI. The cause is determined to be an error in the existing along-scan correction. The original correction was developed using cold scene data alone, which cannot properly correct biases for warm scenes. A new correction, accounting for both cold and warm scenes, is derived and applied to the GMI data. It properly corrects for the along-scan anomalies across the full dynamic range of on-Earth TBs.