Humidity Profile Retrieval from SAPHIR On-Board the Megha-Tropiques

The Megha-Tropiques (MT) satellite, a joint Indo- French mission, was launched by ISRO's PSLV-C18 on 12 October 2011 from Sriharikota, India. SAPHIR, a microwave humidity sounder on-board Megha Tropiques operates in six channels with frequencies around 183.31 GHz. A radiative transfer simulationbased operational algorithm has been developed to retrieve layer-averaged relative-humidity (LARH) for six atmospheric layers from the surface to nearly 12 km using SAPHIR observations over land and ocean under non-rainy conditions. SAPHIR-derived LARH for the period July to November 2012 has been validated with concurrent quality-controlled radiosonde observations as well as with ECMWF analysis data. Global validation with radiosonde and ECMWF data shows that ischolar_main mean square deviation in LARH for all the six layers is nearly 20% and 15% respectively, after bias correction.