2. Radar Basics - 1 What is Radar? Transmission and reception of Electro-Magnetic radiation via echo location.Collimated into a beam and scannedUsually pulsed and many pulses per secondDetects objects and their location.Why Radar? Radar is able to operate day or nightRadar is able to operate in all weathersRadar has very broad coverageDetects and tracks moving objectsHigh resolution ImagingObject recognitionWeather Radar Weather Radar Katrina 2005Weather Radar Sandy 2012 Terra SAR-X Image of Sydney, Australia The Future Vehicular Radar Vehicular Radar Vehicular Radar Vehicular Radar Radar Detects and tracks objects of interestMeasures the location of objects remotely in rangeand angleGeneratesimageryoftheground(andotherobjects)Abletoprovideverywidecoverage(e.g.3600,global)Operates day and night and in all weathersCanprovideinformationaboutobjecttypeandintentSchematic Diagram of aSimple Radar System Im Listening Wavelength and Frequency c = f !Phase Intensity of spherical waves Polarization The electric-eld of a wave travelling in the Z direction is in the x-y plane as dened by Ex and Ey .If Ex = 0, or Ey = 0 then the polarization is linear. If Ex= Ey and they oscillate in phase, the eld will oscillate linearly along a 450 line in the x-y plane.If Ex= Ey and are a multiple of pi/2 put of phase the polarization is circular and if Ex is not equal to Ey the polarization is elliptical.Diffraction Beams Refraction and Reflection Primary Air Traffic Control Radarat Heathrow Airport , London, UK Air Traffic Control Radar (ACTR) ALE 3X5 Maccarese, Italy Courtesy of AMS A. Farina, June 2003 Civil marine band radar used by shipping throughout the world. Allcommercialcraftarelegally obligedtocarrysuchradar systemsCivil Marine Radar Martello UK Air Long Range DefenceRadar System US E3-D Sentry Airborne Early WarningRadar System Captor Radar for TYPHOON Aircraft Airborne Intercept Radar Courtesy of BAE SYSTEMSBYSON UK Experimental Radar AEGIS AN-SPY1 Air Defence MESAR-1 Experimental Phased Array Naval Air Defence Early Bistatic Radar Experimentsat UCL Grifths, H.D. and Carter, S.M., Provision of moving target indication in an independent bistatic radar receiver; The Radio and Electronic Engineer, Vol.54, No.7/8, pp336-342, July/August 1984 .94 GHz SAR Experimental Systemsometimes used in Missile Seekers