For scientific observation using a lunar and a planetary lander, the pinpoin
t landing technology that ambiguity is less than 100m must be needed to land
ing system. A landing radar that measure an altitude and velocity of a space
craft with microwave is very important navigation sensor to realize the pinp
oint landing. It is a mandatory sensor for any future missions of planetary
landing. This report describes that the current status of the BBM developmen
t and the result of field experiment using a helicopter.