Search for: All records

Electromagnetic waves excited by satellites and space debris moving through the earth’s plasma in low earth orbit can be detected in situ by a technique called Space Object Identification by Measurements of Orbit-Driven Waves (SOIMOW). Proximity measurements of space objects with plasma waves may allow tracking of space debris below the normal detection thresholds traditionally accomplished by optical telescopes and radar ranging sensors. SOIMOW uses in situ plasma receivers to identify space objects during orbital conjunctions. Satellites and other space objects moving through the near-earth ionosphere between 200 and 1000 km altitude become electrically charged by both electron collection and photo emission in sunlight. These hypersonic, charged objects excite a wide range of plasma waves. The SOIMOW technique has shown that electromagnetic plasma waves from known objects may be observed out to ranges of tens of kilometers, providing information on presence of the space objects. The SOIMOW concept has been demonstrated with the Radio Receiver Instrument (RRI) on the Swarm-E satellite. The amplitude, spectral, and polarization changes of the RRI data are consistent with electromagnetic, compressional Alfvén waves that are launched by charged space objects traveling across magnetic field lines. In addition, electrostatic waves at the space object can be generated by a lower hybrid drift or an ion acoustic wave instability. Both in situ electric field probes and remote detection of scattered satellite waves are being investigated to determine the location of orbiting objects.