Doppler Correction Algorithm for EarthCAER Cloud Profiling Radar

Engeneering tests of W-band Cloud Profiling Radar (CPR) for EarthCARE (Earth Clouds, Aerosols and Radiation Explorer) were almost finished successfully and a flight model for CPR/EarthCARE is now manufactured for satellite launch in 2015. A Doppler measurement function is one of the unique features of CPR/EarthCARE and new algorithm is needed to estimate vertical Doppler velocity with good accuracy from CPR. Since the satellite will fly horizontally with very high speed, miss beam pointing and wide Doppler spectral width cause big estimation error of small vertical velocity of cloud echo. We also noticed that horizontally inhomogeneous reflectivity make significant Doppler estimation error due to contamination of satellite velocity component. So, we are trying to develop algorithm to correct this error. We will introduce the concept of this algorithm and show its effectiveness using some examples.