The measurement accuracy of range original segment is very important for the safety of a launching site. This paper, starting from radar environment of the launching site, analyzes the principle of MTT (moving-target-tracking) and the problem of moving target's Doppler modulation. In order to guarantee the measuring accuracy, radar system must be compensated. By means of the data analysis of the computer simulation and engineering model at range, it shows that compensation technique is an effective measure which implements original segment measurement of carriers (satellite, rocket, missile).
