The GPM Operational Radiometer Algorithm - Changes for 2021
<p>The Global Precipitation Measurement (GPM) mission was launched in February 2014 as a joint mission between JAXA from Japan and NASA from the United States.&#160; GPM carries a state of the art dual-frequency precipitation radar and a multi-channel passive microwave radiometer that acts not only to enhance the radar&#8217;s retrieval capability, but also as a reference for a constellation of existing satellites carrying passive microwave sensors.&#160; In May of 2017, GPM released Version 5 of its precipitation products starting with GMI and continuing with the constellation of radiometers.&#160; The precipitation products from these sensors are consistent by design and show relatively minor differences in the mean global sense.&#160; Since this release, the Combined Algorithm hydrometeor profiles have shown good consistency with surface observations and computed brightness temperatures agree reasonably well with GMI observations in precipitating regions.&#160; The same is true for MIRS profiles in non-precipitating regions.&#160; Version 7 of the GPROF code will therefore make use of these operational products to construct it's a-priori databases.&#160; This will allow continuous improvements in the a-priori database as these operational products are reprocessed with newer versions, while allowing the user community to better focus on the algorithm&#8217;s error covariance matrix and its validation. &#160;Results from early versions of this algorithm will be presented.&#160; In addition to creating an a-priori database that can be more directly updated with improvement to the raining and non-raining scenes, GPROF is also undertaking steps to improve the orographic representation of snow and a Neural Network based Convective/Stratiform classification of precipitation that will both help improve instantaneous correlations with in-situ observations.</p>