说明：  美国GPS现代化建设现状综述 目前，GPS共有31颗组网工作卫 星，包括11颗Block IIA卫星、12颗 Block IIR卫星、7 颗Block IIR-M卫 星和1颗 Block IIF卫星。其中最新的 Block IIF首颗卫星于2010年5月27日发 射，8月投入运行，该星首次传输了GPS L5民用导航信号。
(Summarization of the U.S. GPS modernization, GPS, a total of 31 working as a network of satellite, including 11 Block IIA satellite, the 12 Block IIR satellites, 7 Block IIR-M satellite, a Block IIF satellites. Block IIF first satellite launched on May 27, 2010, put into operation in August, the star for the first time to transmit the GPS L5 civil navigation signals.)