Proceedings with Extended Abstracts (single PDF file) - Radio ...

4 Discussion and ConclusionWe have briefly described the circumstances in which one might use transmittersof opportunity to synthesize fairly sensitive MST radars with relativelylow cost receive-only systems. This idea is motivated by success in using passiveradar to observe ionospheric turbulence at high latitudes by observingbistatic scatter of commercial FM broadcasts at 100 MHz.Two key experimental issues need to be addressed: the proximity ofground clutter to the desired scatter; and the geometric dilution of precision(GDOP) on the forward scatter path. However, the GDOP provides anopportunity to use higher frequency, UHF television broadcasts, both currentNTSC and future digital waveforms. These signals have very high averagepower and should provide net altitude resolution of about 250 m.Ultimately such systems are unlikely to offer the resolution and sensitivityof conventional active MST systems. However, the low cost, safety, andsimplicity of passive systems may make them very useful for networked coverageover wide areas. As computing becomes larger and internet connectivitybecomes more ubiquitous and faster, the passive or parasitic radar becomesmore and more attractive.AcknowledgementThe author wishes to express his gratitude to the US National ScienceFoundation for its support of this work.478