Digitally Steered Phased Antenna Array for GPS Applications

GPS signals are sparse and weak at high altitudes above the GPS constellation; this includes GEO and HEO orbit regimes. Spacecraft operating here need a high-sensitivity receiver capable of acquiring and tracking these weak signals throughout their orbits. Most space GPS receivers are designed to operate in the LEO regime below the GPS constellation and will perform poorly at high altitude. The Goddard Space Flight Center (GSFC) Navigator GPS receiver is designed for above-the-constellation applications and can provide adequate performance for many missions. The innovation described here provides large sensitivity increase through improvement of the receiver’s antenna gain. The technology can be applied to a standard LEO GPS receiver to enable adequate high-altitude performance, or to a specialized high-altitude receiver, like the GSFC Navigator, to further improve its high-altitude performance. The innovation can also be used to mitigate interference, including multipath and RF jamming signals for operation in any regime.