Future Radar Observation of Precipitation From Space
Abstract
A spaceborne radar has been available since December 1997. The radar is onboard a satellite "Tropical Rainfall Measuring Mission (TRMM)" satellite. Contrary to ra- diometers, the radar directly detects rain regardless of over land and ocean. Thanks to its range resolution capability, the radar gives us three dimensional rain structure. TRMM observation is, however, limited to plus or minus 38 degree latitudes. TRMM follow-on precipitation observation mission plan, called ATMOS-A1 was discussed for a long time. NASA proposed the Global Precipitation Measurement (GPM) which consists of a core satellite and many small satellites equipped with microwave ra- diometers. ATMOS-A1 has merged to GPM and takes an essential part as a core satellite in GPM. The ATMOS-A1 can provide precise and accurate rain measure- ments including three dimensional precipitation structure for the microwave radiome- ter rain retrievals. The small satellite constellation of GPM remedy limited sampling frequency of ATMOS-A1 and also gives a possibility to study precipitation evolution. Since the ATMOS-A1 mission includes global observation of liquid/solid precipita- tion structure, the radar should have higher sensitivity, better accuracy and liquid/solid discrimination capability. To meet these requirements, a 14/35 GHz dual-wavelength radar has been proposed. The swath and spatial resolution of the Ku-band (14 GHz) radar should remain as the TRMM precipitation radar. The sensitivity of the Ka-band radar is a big issue. Current idea for the Ka-band radar is to to degradate the range resolution to 500 m to attain sensitivity of nearly 10 dBZ and the swath is about 100 km.
- Publication:
-
EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27..679N