1. Tracking Radar Measures the coordinate of a target for determining thetarget path as well as to predict its future coordinates Based on the measured coordinated error signal will be generated Antenna should be moved based on error signal to maintain the target within the beam. Tracking of range, angle, Doppler frequency shift and radial velocity Uses pencil beam

2. Angle tracking Two beams are squinted Crossover of two beam:boresight Boresight always maintained in the direction of the target Relative amplitude of two beam determines how far the target is from boresight Also direction in which beam needs to be repositioned 2 beams in both the coordinate 3. Methods of generating error signal Conical scan or sequential lobing tracker Time shares a single beam Antenna beam is switched between two positionsSimultaneous lobing or monopulse More than one simultaneous beam is used for tracking Usually 4 simultaneous beams to perform 2dimensional tracking 4. MonopulseTracking Radar Radar in which information concerning the angularlocation of the target is obtained by comparing the signal received in two or more simultaneous beams. Two offset antenna beams are combined to obtain both sum and difference signal This signals are multiplied in a phase sensitive detector to obtain both magnitude and direction 5. Amplitude comparison monopulse 6. Amplitude comparison monopulse Twoadjacent antenna feeds are connected to the 2 input arms of a hybrid junction Sum and difference signal Difference channel produce error voltage appro proportional to the angular deviation of the target from the boresight 7. Amplitude comparison monopulse By comparing the phase of sum and difference signaldirection of angle error is found Depending on these information's the servo meter will drive the antenna back to the target Phase sensitive detector is used to compare the phase of two signals 8. Monopulse in two angle coordinate 9. Monopulse in two angle coordinate 10. Monopulse in two angle coordinate All four feeds are used to generate sum pattern i.e A+B+C+D Azimuth difference channel: (A+B) (C+D) Elevation difference channel: (B+D) (A+C) Two angle errors Elevation angle error : o/p of phase comparison b/wsum channel and Elevation difference channel Azimuth angle error : o/p of phase comparison b/w sum channel and Azimuth difference channel 11. Phase comparison monopulse Instead of comparing the amplitude of the echoesfrom two squinted beams , the angle of arrival from a target is determined by comparing the phase difference between two signals Uses two separate beams from two separate antenna looking in same direction 12. Phase comparison monopulse An echo on boresight will arriveat the two antennas at the same time and therefore the phase difference will be zero An echo from a target at an angle q to boresight will arrive at one antenna later than the other due to the extra distance it travels. 13. Phase comparison monopulse Extra distance travelledby one echo w.r.t other is given byOr expressed as phasedifferencePhase detector is usedto find the angle error 14. Phase comparison monopulse 15. Comparison Amplitude-comparisonPhase compariosonHas high SNRGrating effect : highTwo feeds at the focus ofsingle antenna Squinted beams usedsidelobes are produced in the sum pattern resulting in angle measurement ambiguities two separate antenna are used Beams are not squinted but look in same direction