Effect of Earth's rotation and range foldover on space based radar performance

S. Unnikrishna Pillai, Braham Himed, Ke Yong Li

Research output: Contribution to journalConference articlepeer-review


A space based radar (SBR) 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 also adds 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. Further, it is shown that the crab angle has maximum effect for an SBR on a polar orbit that is above the equator. The crab magnitude on the other hand peaks for an SBR on an equatorial orbit. It is also shown that Earth's rotation together with range foldover phenomenon significantly degrade the clutter suppression performance of adaptive processing algorithms. Detailed derivations of these results are presented in this paper.

Original languageEnglish (US)
Article number1435808
Pages (from-to)137-142
Number of pages6
JournalIEEE National Radar Conference - Proceedings
Issue numberJanuary
StatePublished - 2005
Event2005 IEEE International Radar Conference Record, RADAR 2005 - Arlington, United States
Duration: May 9 2005May 12 2005


  • STAP
  • crab angle
  • earth's rotation
  • range foldover
  • space based radar
  • waveform diversity

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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