SECOR 4 (EGRS 4)
 | |
|---|---|
| Frequencies | 136.8452 MHz,136.845 MHz |
| Frequency Range | 136.845 MHz - 136.8452 MHz |
| Mode | USB |
| Modulation | IRIG |
| ACF | — |
| Emission Designator | — |
| Bandwidth | 2 kHz |
| Location | |
| Short Description | SECOR 4 (COSPAR ID: 1965-027B) was a SEquential COllation of Range series satellite, and is occasionally active when receiving adequate solar power on it's panels. It is not consistent, likely owing to a tumbling or rotating motion. |
| I/Q Raw Recording | — |
| Audio Sample | |
SECOR 4 (NORAD 01315) is one of many "zombie satellites" that will occasionally power back on and begin transmitting it's telemetry signal.
"Geodetic SECOR (Sequential Collation of Range) was an all-weather geodetic survey system which was in operational use for several years, establishing a global survey network. It used the successive positions of artificial satellites in space to determine locations on the earth's surface with exactness over long distances. The system consisted of a satellite and four ground stations. Three at geographical points where the co-ordinates had been surveyed accurately and the fourth at an unknown location. Radio waves were flashed from the ground stations to the satellite and returned. The position of the satellite at any time was fixed by the measured ranges from the three known stations. Using these precisely established satellite positions as a base, ranges from the satellite to the unknown station were used to compute the position of the unknown station. Geodetic SECOR allows continents and islands to be brought within the same geodetic global grid. Each ground station was entirely portable and contained three units: a radio frequency shelter, a data handling shelter and a storage shelter. Lighter weight, solid-state equipment was developed to replace the initial units. The satellite had a mass of 18 kg and contained a transponder, a telemetry system to monitor temperature and operating voltages, and a power unit comprised of solar panels and batteries." -
