The exploitation of a mode locked train laser pulse for satellite ranging has been used. The Nd YAG oscillator/amplifier/frequency doubler/laser generates a mode locked train at 0.53um, most of the energy is contained in three pulses, the individual pulse duration is 70psec. During the 1963 Merit Campaign, within 4 months, 10 low satellite passes and 31 Lageos passes have been ranged. When tho mode locked substructure has been resolved for the received signal (50 % of passes), the BMS was 6-8 cm.
To range the satellite, we are using the train of picosecond pulses generated by Nd YAG oscillator / amplifier / second harmonic generator laser system. To establish an optimum discriminatior / timing system, the indoor and the short baseline outdoor calibration experiments were used. The experimental results indicate a limit single shot uncertainty 6cm PMS.
One of the limiting factors in decreasing the systematic error of laser ranging is the influence of the atmospheric refraction. Two colour ranging may contribute useful information for more precise refraction factor modelling and calculation. We will describe two wavelength experiment using streak camera as a high resolution detector for ground target distance measurement.