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Control techniques of delay-time jitter from the echo-transponder satellite laser ranging

Because of the familiar R2 dependence of signal strength on range and overcoming the prohibitively large R4 losses of conventional passive satellite laser ranging(SLR), the operational distance of echo-transponder satellite laser ranging is much farther. Echo-transponder SLR can be used for satellite ranging at great distance, and even for deep-space probe ranging. Echo-transponder SLR uses a laser transponder instead of the retro-reflector on the satellite, and implements ranging by means of echoing the ranging signal from the master station. However, ranging accuracy of echo-transponder SLR is reduced, because the jitter of additional delay-time occurs in the process of the transponder’s response. The principle of laser echo-transponder was introduced, the causes of delay-time and its jitter were analyzed, and the control technique of delay-time jitter in responsion was studied. An experimental platform of the laser echo-transponder was constructed, in order to validate the availability of the control technique of delay-time jitter, and to detect control accuracy of the delay-time jitter. As the experimental result indicated, the delay-time jitter of the laser echo-transponder could be controlled effectively within 1 ns, thereby it was determined that the corresponding ranging error was less than 15 cm, if the laser transmitter was suitably selected, and the techniques about precise temperature control, automatic power control, precise Q-switched, and accurate detection of the pulse moment were reasonably put to use in the system design of the laser echo-transponder. Meanwhile the feasibility of echo-transponder SLR was validated.