On-Orbit Performance of the Improved GPS Block IIR Antenna Panel

摘要

The Block IIR Space Vehicle (SV) is currently in the process of being modernized. The new IIR-M will add three new signals and three new codes (L1M, L2M, L2C), providing the civil community with the capability to correct for ionospheric errors and providing the authorized user with new jam-resistant signals. As a stepping-stone toward the modernized IIR, Lockheed Martin has developed and deployed an improved satellite antenna panel. It includes redesigned L-Band elements and new UHF antennae for the on-orbit crosslink. This antenna panel provides greater signal strength on both the L1 and L2 bands. This paper will describe the new antenna panel, its performance observed in factory testing, and its on-orbit performance. The final four "Classic" Block IIR SVs were retrofitted with the new panel and placed on-orbit in 2004. Ground power measurements reflect the increased antenna gain shown by the factory measurements. The L1 band shows an increase of 1 dBW in received power at edge of earth and L2 shows an increase of 2 dBW in received power at edge of earth. All users will benefit from this enhanced power profile.