24-10-2012, 12:25 PM
Non-GPS Geolocation for Space and Terrestrial Applications
ABSTRACT
Some near and far term space missions involve formation flying, which requires that the positions of multiple spacecraft
be accurately known relative to a hub spacecraft. Many such missions will be located far outside the radius of the GPS
constellation. So in such missions it will not be possible to derive position knowledge through the capabilities afforded by the
GPS service. Consequently, in such missions, it is necessary to determine relative positions by other means. Depending on how
well a position must be known, thus far it has appeared necessary to use means other than RF ranging, due to technical
limitations. Once spacecraft have been crudely positioned using RF ranging, other tools such as star trackers, ccd cameras,
and laser ranging are to be used for precise and accurate ranging. NASA Glenn is investigating an innovation in RF ranging
that could be very useful for extending the capabilities of RF ranging in many circumstances. Currently, this innovation is a
technical secret, but this paper will discuss the possibility of using RF triangulation for the purposes stated in its title, without
disclosing any proprietary information. This paper includes a simulation that successfully illustrates how this technology could
be used to perform vehicle tracking.