Differential satellite laser ranging as a system calibration tool

We are presenting a new satellite laser ranging technique. 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 internal delay, ground survey, satellite orbit modeling, atmospheric correction and satellite signature. Due to this fact the baseline may be determined with high accuracy on the basis of several satellite passes, only. The presented technique may be used as a powerful tool for satellite laser ranging systems diagnostics. 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 double - check the system internal delay - the calibration value, once the ground target ranging is inaccurate or even impossible.