PRECISION TIME COUNTER FOR LASER RANGING TO SATELLITES

A new design of the precision time counter for satellite laser ranging is described. The instrument features 3 ps incremental resolution within the measuring range up to 21.47 s, the short-term rms error below 30 ps, and the time drift within +/- 5 ps. To reject unwanted noise and other disturbing signals the programmable window discriminator has been employed. In order to achieve high accuracy and good long-term stability we used an automatic calibration based on the adaptive prediction. Further significant reduction of the measurement error has been achieved by self-correction of the nonlinearity error and robust estimation. Results from experimental tests are presented to demonstrate the performance of the instrument.