Doppler measurements of cloud profiling radar of EarthCARE

Following the successful satellite mission of CloudSat and CALIPSO to measure global cloud and aerosol, European and Japanese space agencies plan to launch a satellite called EarthCARE (Earth Clouds, Aerosols and Radiation Explorer) in 2013. A W-band Cloud Profiling Radar (CPR) is installed on this satellite as well as a high spectrum resolution lidar (ATLID). EarthCARE CPR has more sensitivity than CloudSat CPR due to larger antenna size and lower satellite orbit. Minimum detectable radar reflectivity factor is now designed as -35dBZ at top of the atmosphere with 10 km horizontal integration. Other feature of CPR/EarthCARE is a Doppler function. CPR/EarthCARE will try to measure vertical Doppler velocity of cloud echoes with higher PRF, which are important for cloud physics and drizzle detection. This is the first trial to measure the vertical Doppler velocity from space, so there are many issues on Doppler measurement accuracy. Since the satellite will fly horizontally with very high speed, small speed detection of vertical speed of cloud is difficult task and challenging work.

CPR on EarthCARE is going to develop mainly in Japan side (NICT and JAXA) in cooperation with European Space Agency (ESA). The latest status of CPR design will be introduced in this presentation.