Improvement of the minimum detectable precipitation echoes with the TRMM precipitation radar and the GPM dual-frequency precipitation radar

摘要

Increasing the detectability of precipitation echoes with spaceborne weather radar is desirable, especially to detect snowfalls. This paper describes a possible method that may increase the detectability of weak precipitation echoes in received signals of the TRMM Precipitation Radar (PR) and the GPM Dual-frequency Precipitation Radar (DPR). The proposed method is based on a probabilistic consideration of existence of precipitation. In this formulation the estimate of echo power may change for a given measured received power depending on our belief of existence of precipitation. By assigning a proper a priori probability of precipitation and setting an appropriate threshold, we may be able to increase the detectability of precipitation echo without sacrificing the reliability of judgement.