Optical rangefinders are the component part  of the modern systems of global satellite  navigation. Limitation of laser average power necessitates to choose between rare high energy pulses and frequent weaker pulses. Due to high cost of experimentations with basic parameters  of satellite systems, the article describes  a possibility of theoretical evaluations  of existing variations efficiency. The given calculation method (based on the corpuscular representation of optical signals in the Poisson approximation) provides a possibility  to investigate effects of laser sounding frequency change and the amplitude discrimination  of signals. The rangefinder «Sazhen-TM»,  whose parameters are far from optimal,  is described in the article as an example.  КУРАКИН