Article Posted on : - Jul 31, 2009

The two space agencies will partner in making the GPM mission a success.

CAPE CANAVERAL (BNS): US space agency NASA and Japan Aerospace Exploration Agency (JAXA) have joined hands to work on the Global Precipitation Measurement (GPM) mission.

The GPM mission is aimed at providing uniformly calibrated precipitation measurement globally for two to four hours daily. This will help in scientific research and other societal purposes, the US space agency said on Thursday.

The two space agencies have earlier worked on the Tropical Rainfall Measuring Mission (TRMM). Based on its success, the GPM mission – a key climate factor – will be implemented, NASA said, adding that the international collaboration will also use data provided by other global partners in the project.

GPM is also the cornerstone of the multinational Committee on Earth Observation Satellites Precipitation Constellation that addresses one of the key observations of the Global Earth Observation System of Systems.

The heart of the GPM mission is a space-borne core observatory which serves as a reference standard to unify measurements from a constellation of multinational research and operational satellites carrying microwave sensors, according to NASA.

For the first time, the GPM core observatory sensor measurements will make detailed observations of precipitation particle size distribution, which is key to improving the accuracy of precipitation estimates by microwave radiometers and radars.

The core observatory will carry a dual-frequency precipitation radar (DPR), which operates at Ku and Ka band frequencies, and a multi-channel GPM microwave imager (GMI). The DPR will measure light rain and snowfall more effectively than the TRMM radar. The GMI uses a set of frequencies that have been optimized to retrieve heavy, moderate, and light precipitation estimates.

As per the agreement, NASA will look after the GPM core observatory spacecraft bus, the GMI carried by it, and a second GMI to be flown on a partner-provided Low-Inclination Observatory. JAXA will supply the DPR for the core observatory, an H-IIA rocket for the core observatory's launch in July 2013 and data from a conical-scanning microwave imager on the upcoming Global Change Observation Mission satellite.