DYE 4 - Distant early warning radar station, in Greenland, Kulusuk 1962

DYE 4 is one of nearly 60 radar sites set up during the Cold War as part of an early-warning detection system that stretched across the far north of Canada. Build in cooperation between the US and Canada, the project was a hugely expensive undertaking, and DYE-4 was one of its most vital links. System was abandoned in the late 1980s when satellites made its 200-foot-tall radar domes obsolete, but the structures are still standing-according to recent visitors, snow drifts fill most of the rooms now. DYE 4 was decommissioned 24 Sept 1991.

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Cognitive Radar Network: Cooperative Adaptive Beamsteering for Integrated Search-and-Track Application

Romero, R.A.; Goodman, N.A., "Cognitive Radar Network: Cooperative Adaptive Beamsteering for Integrated Search-and-Track Application," Aerospace and Electronic Systems, IEEE Transactions on , vol.49, no.2, pp.915,931, APRIL 2013
doi: 10.1109/TAES.2013.6494389

Abstract: Cognitive radar (CR) is a paradigm shift from a traditional radar system in that previous knowledge and current measurements obtained from the radar channel are used to form a probabilistic understanding of its environment. Moreover, CR incorporates this probabilistic knowledge into its task priorities to form illumination and probing strategies, thereby rendering it a closed-loop system. Depending on the hardware's capabilities and limitations, there are various degrees of freedom that a CR may utilize. Here we concentrate on spatial illumination as a resource, where adaptive beamsteering is used for search-and-track functions. We propose a multiplatform cognitive radar network (CRN) for integrated search-and-track application. Specifically, two radars cooperate in forming a dynamic spatial illumination strategy, where beamsteering is matched to the channel uncertainty to perform the search function. Once a target is detected and a track is initiated, track information is integrated into the beamsteering strategy as part of CR's task prioritization.

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