Precision of satellite laser ranging calibration of the Naval Space Surveillance System

The Naval Space Surveillance System is a network of radio frequency interfe rometer stations designed to detect satellites. Angular metric data from th e system are used in real time to update the catalog of known space objects maintained by the U.S. Air Force and Naval components of United States Spa ce Command. For many years the system has operated with a near real-time ca libration of the detector electronics but without a rigorous tie to an exte rnal reference frame. One way to establish such a tie is by comparing syste m measurements with data derived by satellite laser ranging. In principle, public-domain laser ranging data on geodetic satellites can always be used to generate a few high-precision reference orbits whose ephemerides can be compared with surveillance measurements. In the right circumstances special laser tracking data on any suitable satellite can be taken simultaneously with surveillance measurements and compared directly. Both approaches offer benefit to space surveillance operations, and both have been demonstrated in previous work. This analysis initiates the analytical investigation of h ow precisely errors can be resolved in the surveillance measurements, using laser ranging derived data. Equations are presented, which relate Naval sp ace surveillance uncertainties to reference data uncertainties in explicit terms. Simple geometric measurement models are considered, rather than deta iled physical measurement models, in order to provide fundamental understan ding of how errors transform in the two types of calibration considered. Th e resulting formulas are suitable for deriving calibration requirements and simplified error budgets, either analytically or by numerical simulation.