Accession Number : ADA309748

Title :   Aerospace Applications of Navigation Satellites,

Corporate Author : NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH

Personal Author(s) : Yu, Yao ; Liyu, Zhang

PDF Url : ADA309748

Report Date : 13 MAY 1996

Pagination or Media Count : 13

Abstract : The United States' Navstar Global Positioning System (Navstar-GPS) and Russia's Global Navigation Satellite System (Glonass) are the new-generation global satellite radio navigation systems each developed separately in the 1970s. Their appearance fundamentally changed the concept of global navigation. The GPS satellite system is composed of a constellation of 24 satellites at an altitude of approximately 20,000 kilometers, distributed in orbits at six equivalent intervals. The orbital planes are at 55 degrees relative to the included angle of the equator, and there are four satellites in each orbital plane. The satellites' orbital planes are approximately circular, and their period of revolution is about 11 hours and 58 minutes. This satellite distribution can ensure that anywhere in the world, at any time, at least four satellites are provided for observation. Similarly, the Glonass system will also deploy 24 satellites. Glonass satellites are positioned on three orbital planes at intervals of 120 degrees, their orbital altitude is approximately 19,000 kilometers, their orbital inclination is about 65 degrees, and their period of revolution is 12 hours. GPS and Glonass each have their own individual characteristics and advantages but, as of now, most users' receivers can only receive satellite signals from one of the systems. Development of an integrated receiver that can receive satellite signals from both GPS and Glonass will certainly raise navigation accuracy by a large margin. GPS and Glonass are two mutually independent systems but, in recent years, integrated use of both systems has become possible. Integrated receivers can either receive GPS or Glonass signals alone or use a combination of their signals, and can provide more complete navigation service than using only one of the systems can.

Descriptors :   *AEROSPACE SYSTEMS, *GLOBAL POSITIONING SYSTEM, *NAVIGATION SATELLITES, ANGLES, EQUATORIAL REGIONS, INCLINED ORBIT TRAJECTORIES, ORBITS, GLOBAL, INTEGRATED SYSTEMS, ACCURACY, NAVIGATION, SIGNALS, RECEIVERS, ARTIFICIAL SATELLITES, TRANSLATIONS, ALTITUDE, CHINA, INTERVALS.

Subject Categories : Navigation and Guidance
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE