A new satellite laser ranging technique has been invented, software modeled and field tested at CTU. The Differential Satellite Laser Ranging (DSLR) is a technique providing highly accurate short ground baselines and relative station heights. Two satellite laser ranging systems are sharing one common laser transmitter. Recording the echo pulses arrival times at different locations, the corresponding baseline and relative station height may be evaluated. Due to the differential approach, most of the error contributors present in the conventional satellite laser ranging are minimized or not existing at all: system calibration, ground survey, satellite orbit modeling, atmospheric correction and satellite signature. Due to this fact the baseline and height difference may be determined with high accuracy on the basis of several satellite passes, only. The DSLR technique performance has been tested by a series of software modeling, the numerical experiments predicted the achievable baseline precision comparable to the satellite laser ranging normal point precision. Just two to five satellite passes well distributed over an entire sky provide sufficient amount of data for such a solution. The numerical model predictions have been verified by the real experiment - satellite laser ranging at the station Helwan, Egypt.
The presented technique may be used as a powerful tool for satellite laser ranging systems diagnostics. Of particular importance is the fact, that the system calibration constant of either system is not included in the evaluation of the baseline. The DSLR opens new perspectives: in collocation experiment it permits to check the system calibration independently on the ground target ranging. For the laser ranging systems equipped with several independent receivers the DSLR enables to evaluate the system calibration value, once the ground target ranging is inaccurate or even impossible.
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