SLR2000: AN INEXPENSIVE, FULLY AUTOMATED, EYESAFE SATELLITE LASER RANGING SYSTEM

SLR2000 is an autonomous, unmanned satellite laser ranging station with an expected single shot range precision of about one centimeter and a normal point precision better than 3 mm. The system will provide continuous 24 hour tracking coverage and reduce capitalization, operating and maintenance costs by an order of magnitude relative to current outlays. Computer simulations have predicted a daylight tracking capability to GPS and lower satellites with telescope apertures under 50 cm and have demonstrated the ability of our current autotracking algorithm to extract mean signal strengths as small as 0.0001 photoelectrons per pulse from noise. The dominant cost driver in present SLR systems is the onsite and central infrastructure manpower required to operate the system, to service and maintain the complex subsystems (most notably the laser), and to ensure that the transmitted laser beam is not a hazard to onsite personnel or overflying aircraft. In designing the SLR2000 system, preference was given to simple hardware over complex, to commercially available hardware over custom, and to passive techniques over active resulting in the prototype design described here. This general approach should allow long intervals between maintenance visits and the “outsourcing” of key central engineering functions on an “as needed” basis. In unassembled “kit” form, the per system hardware costs for SLR2000 are expected to be less than $300K. A fully assembled and tested field system should be reproducible for about $500K per system in quantities of eight or more.