抄録
The spaceborne radar to measure rain has not been realized yet. In this paper, the airborne rain radar and the result of the joint experiment between USA and Japan is introduced in the beginning. Then, the plan of the Tropical Rainfall Measuring Mission (TRMM) is introduced with the results of conceptual design study and development of the BBM (Bread Board Model) of the TRMM rain radar. The radar, operating at 13.8 GHz and designed to meet TRMM mission objectives, has the minimum measurable rain rate about 0.5 mm/h with a range resolution of 250 m, a horizontal resolution of about 4 km, and a swath width of 220 km. An active phased array radar system with the 128-element is adopted to achieve a contiguous scanning within the swath. The basic characteristics of BBM were confirmed by experiments.