A reconnaissance satellite (AKA- a 'spy satellite', 'eaves dropping satellite' or 'spies in the skies system') is an orbiting Earth observation on to the planet's surface type space satellite or communications interception and/or dispersal satellite deployed for military or intelligence gathering and/or dispersal applications. The USA began drawing up the first plans for one in 1955 and the USSR started there own plans a year later.
Some examples of reconnaissance satellite missions are:
- High resolution photography (IMINT).
- Measurement and Signature Intelligence (MASINT).
- Communications eavesdropping (SIGINT).
- Covert communications.
- Monitoring of Comprehensive Test Ban Treaty compliance (by 'National Technical Means').
- Enforcing ceasefires by watching the movement of aircraft, armour and ships.
- Detection of missile launches.
- Missile [Launching] Early warning provides warning of an attack by detecting ballistic missile launches.
- Nuclear explosion detection identifies and characterizes nuclear explosions in space.
- Photo surveillance has images taken of Earth so theycan be a survey or close-look telephoto is the earliest known. Spectral imaging is now commonplace.
- Electronic-reconnaissance and Signals intelligence intercepts stray radio waves.
- Radar imaging use space-based radars use synthetic aperture radar to take scrimmages at night or through heavy fog and cloud cover.
Earth observation satellites' transmission frequencies
|Terra||8212.5 MHz||X band|
|Aqua||8160.0 MHz||X band|
|National Oceanic and Atmospheric Administration (NOAA) 17,18||1707.0 MHz||L band|
|European Remote Sensing Satellite (ERS-2) (High rate)||8140.0 MHz||X band|
|SPOT 4,5||8253.0MHz||X band|
|EROS A1||8150.0 and 8250.0 MHz||X band|
|Landsat 5, Landsat 7||8212.5 MHz||X band|
|China-Brazil Earth Resources Satellite program (CBERS) 2B||8103.0, 8321.0 and 8212.0 MHz||X band|
|Comisión Nacional de Actividades Espaciales (SAC-C)||8386.0 MHz||X band|
- Spy plane
- Lockheed U-2
- Reconnaissance aircraft
- Secret service radio stations
- Electromagnetic spectrum