The method of tracking space objects by optical surveillance is known as photo-optical reading technique. In this technique, images of space objects and stars are shown at the same time. Then, proper image analysis can distinguish between the stars and space objects
When the distances of several basic stars around the space object are measured, they can be used to determine the direction of the space object’s motion.
Optical surveillance of space objects is very similar to the types of astronomical observations which can be made using visible light. This is because both natural and artificial space objects reflect sunlight and are, therefore, able to be seen using only the visible region of the electromagnetic spectrum.
The relative brightness of the space object to an observer on the ground is determined by the distance between the space object and the sun, the distance between the space object and the observer, and the size and reflectivity of the space object.
Dozens of satellites and space debris are detected on one picture
Marco Langbroek, SatTrackCam Leiden (cospar 4363)
Meteoroid Surveillance
- Meteoroids are monitored by taking advantage of a phenomenon in which air is ionized by the meteoroid.
- By making optical observations through a high speed video sensor, it is possible to obtain the coordinates of the meteor’s trajectory, projected onto the celestial sphere.
- If observations are made of the same meteorite trajectory at many stations installed at different locations, changes in the 3D position of the meteoroid over time can be calculated.
- Therefore, it is possible to measure the position of a meteor entering the earth’s atmosphere, to track its path, and to measure changes in its speed. From this information, it is also possible to determine the orbit of the meteor before it fell to Earth. For real-time monitoring of meteoroids, this technique can be used in conjunction with optical and radar surveillance monitoring.
All-sky multiple cameras for surveillance
- All-sky multiple cameras for surveillance use optical monitoring equipment to detect large space objects that reflect sunlight at night. This equipment can scan the entire sky every second and identify the route of the space object.
- This can simultaneously detect multiple non-specific space objects even when no information is known about their orbit.
