"Wide area surveillance systems are becoming more important for border and homeland security, earth resources monitoring and mitigation of natural disasters such as floods and seismic activity. As the frequency spectrum is being utilized for communications and business networking, the available bandwidth for these important efforts is more difficult. Historically, airborne surveillance radars have been fielded at either UHF or S-Band for airborne vehicle detection, and at X-Band for surface vehicle imaging and moving target detection. This paper will examine the impact of new technologies on the design of L-Band surveillance radars that employ solid state active arrays, multiple phase center apertures and adaptive processing to enable fixed and moving target detection from air and space platforms. The operational advantage of the use of small apertures on business jets, medium apertures on high altitude platforms and very large apertures in space will be contrasted."
Defense Technical Information Center (DTIC): http://www.dtic.mil/dtic/