An Experimental System for Satellite Laser Ranging

A satellite laser ranging system has been made under cooperation with the Hydrographic Department and the Geographical Survey Institute. The receiving telescope is of a Cassegrain type with 40 cm diameter installed on 3-axes type mountings which are driven by pulse motors \nin combination with encorders in three different tracking modes : manual, programing and automatic. A 0. 1 nsec-resolution counter is prepared for measuring flight time. The system has a 500 MHz oscilloscope with a remote controlled camera which makes it possible to study the shapes of the transmitted and received light for accomplishing high ranging accuracy. According to the test operations the transmitted laser energy attains to 3. 3 Joules and the pulse width is 21 nsec. These correspond to 160 MW at peak. In the case of using an electro-optical shutter which is adopted for sharpening the transmitting light, those values become 0. 2 Joule, 6 nsec and 43 MW, respectively. It has been definitely shown by some experiments and test operations that the developed system is valid for precise ranging. \nKey words : laser ranging system