Development results of the precipitation radar on TRMM

Abstract

Precipitation Radar (PR) is a key instrument on the Tropical Rainfall Measuring MIssion (TRMM), which is a joint US/Japan space program. The PR is the first rain radar in space. The characteristics of the PR are high sensitivity, low side lobe level an the high speed electrical beam scanning. On- orbit calibration of the PR instrument will be performed by temperature monitoring of the components, internal loop calibration, and the overall system gain calibration using Active Radar Calibrator placed on the ground. Development and protoflight testing of PR has been completed. PR is now integrated to the TRMM spacecraft and TRMM observatory testing is now under way at Goddard Space Flight Center of NASA. In this paper, systems design, system parameters, on- orbit operation, calibration and the performance test results of PR are reported.