Remote sensing using space based radar

A Space-Based Radar (SBR) is a reconnaissance, surveillance, and target acquisition system capable of supporting a wide variety of joint missions and tasks simultaneously, including battle management, command and control, target detection and tracking, wide area surveillance and attack operations. SBR also supports traditional intelligence, surveillance and reconnaissance missions such as indications, warning, and assessment. These mission areas cover the strategic, operational, and tactical levels of operations of interest. SBR systems are also used for earth science projects. However, an SBR system, by virtue of its motion, generates a Doppler frequency component to the clutter return from any point on the earth as a function of the SBR-earth geometry. The effect of earth's rotation around its own axis is shown to add an additional component to this Doppler frequency. The overall effect of the earth's rotation on the Doppler turns out to be two correction factors in terms of a crab angle affecting the azimuth angle, and a crab magnitude scaling the Doppler magnitude of the clutter patch. Interestingly both factors depend only on the SBR orbit inclination and its latitude and not on the specific location of the clutter patch of interest.