Space Geodesy

Vilnius college of technologies and design. Space geodezy. List of resources Space geodezy. Introduction. What is cosmic geodesy. GPS receivers. The GPS satellites. Access System SA. Conclusions. List of resources.

Each GPS satellite transmits information about its location (coordinates), exact time and identification code to the Earth by radio signals. The GPS system consists of two parts: space and ground. Space support is very expensive. Constantly new polar beads should be launched, replacing those with orbital changes or accidents. Five-time GPS satellites are currently operating: 1. SVN1 - SVN11 satellites. Their advantages: they had 3 very precise ones atomic clocks: 1 cesium and 2 rubies. The GPS satellites of this generation are no longer used.2. SVN13 - SVN21 ​​satellites. Their advantages: they developed very strong communication signals, they could fly for 14 days in a strictly defined orbit without any further adjustments. 3. SVN22 - SVN40 satellites. Their advantages: they were able to maintain a selective access system (SA) for 180 days to fly a strictly defined orbit without additional corrections, had 4 very precise atomic clocks - 2cezium and 2 rubidium, the vitality range was 10-11 years.4. SVN41 - SVN62 satellites. Their advantages: they could have been able to fly a strictly defined orbit for 14 days without additional adjustments, using an autonomous navigation system, had the ability to measure interconnection and distance, 3 precise atomic rubidium clocks, the ability to maintain a selective access system (SA), a viability range of 9 - 11 months.5. IIR-M satellites. Their advantages: better signal quality, laser mirrors, integration with other Earth observation systems, interconnection and inter-distance measurement, life expectancy of up to 11 years. In addition to the positioning and elevation of the GPS surface, GLONASS (Russia), Galileo (ES), IRNSS (India), Beidou and Beidou 2 (China) are used. GPS receivers. These are devices that receive signals from GPS satellites. GPS receivers are used by users on the Earth's surface, on the surface of the ocean and in an atmosphere suitable for aviation, to determine the coordinates of their stay.