Development of the Haystack Ultrawideband Satellite Imaging Radar

The Haystack Ultrawideband Satellite Imaging Radar (HUSIR) is Lincoln Labo-ratory's latest iteration in the technological evolution of high-performance wideband radar systems. As is the case with HUSIR, the distinctive attribute of wideband radar is its ability to resolve a target's individual scattering centers in range, with resolution inversely proportional to bandwidth. If the radar is coherent and the pulse-repetition frequency is sufficiently high, the radar data can be processed to form inverse synthetic aperture radar (ISAR) images and high-resolution range profiles that can be used to identify and characterize targets of interest (Figure 1). Lincoln Laboratory's history with wideband radars dates back to the 1960s, when, motivated by the need to identify and discriminate ballistic missile warheads from other objects, Lincoln Laboratory began to develop high-power wideband radar technology. The first such radar was the Advanced Research Projects Agency (ARPA)-Lin-coln C-band Observables Radar (ALCOR), which became operational at Kwajalein Atoll, Marshall Islands, in 1970. With its 5.7 GHz center frequency, 0.5 GHz bandwidth, 50 cm range resolution, and 23 dB single-pulse signal-to-noise ratio (SNR) on a 1 m 2 target at a range of 1000 km, ALCOR pushed the envelope of then-available technology. While ALCOR was intended to support the development of discrimination techniques for ballistic missile defense, it was quickly recognized that ALCOR, among other wideband radars, could also be used to identify and characterize high-interest objects in space. The development of ISAR algorithms specifically designed for imaging space objects followed soon after [1]. Surveillance Network as the highest-resolution space-object-imaging radar in the world. Its principal mission is to collect space-object identification and characterization data in support of space situational awareness.