Project: Radar Waveforms Generation & Analysis by Matlab Prepared for: Dr. Mohammed Ouda Islamic University of GAZA (IUG) Done By: Jalal Al-Roumy 120050239 Akram Abu-Raida 120061458
* Outlines: v Choice importance. v Factors of choice. v Classification. v Pulse shapes. v Major types. v Matlab Codes. v References. 2
* Why is waveform’s type so important? The correct choice of waveform defines all the main characteristics of the radar as: - Performance of target detection. - Resolution (angular, range and frequency). - Measurement ( range, velocity & error). - Classification and recognition. 3
*Factors of the selection of a particular waveform : Requirements of : - Range coverage. Doppler coverage. Detection probability. Resolving capability. Measurement errors. Interference rejection. Enhanced modes of operation. Cost and complexity. 4
* waveform’s Classification : Depends on the parameter chosen for classification : - Character of variation in time domain. - Usage of intra-pulse modulation or not. - Pulse compression type. - Frequency-coded waveforms types. - Phase-coded waveforms types. - Discretization. 5
* The most popular pulse shapes : - Sinusoidal. Rectangular. Gaussian. Triangular. Sawtooth. Exponential. 6
* Pulse Shapes: 7
8
* Main Waveforms : 9
1 - CW Waveforms : - Eqn. : Et = E 0 cosw 0 t. - Used: CW , Doppler & Bistatic Radars. - Advantages : - Simplified design. - Low power. - Measure target velocity. - Disadvantages: - Need coding to determine range. - Tx & Rx separation at high power. 10
2 - FMCW Waveforms : - Eqn. : f(t) = f 0 + αt. Used: In CW radars. Generation: Active & Passive. Advantages : - Less sensitive to doppler shifts. - Disadvantages: - Has range-doppler cross coupling -> measurement errors. - Range sidelobes are high -> weighting required -> 1 -2 d. B loss in SNR. 11
3 - Simple Pulse : - Eqn. : Et = E 0 cosw 0 t. (for Ton), Et = 0 (for Toff). - Used: Old Radars, Inexpensive Radars. - Types: long & short. - Advantages : - Low cost. - Long: doppler resolution. - Short: range resolution. - Disadvantages: - Long: range resolution. - Short: doppler resolution. 12
4 - LFM Waveforms : - Eqn. : f(t) = f 0 + αt. Used: In pulse radars. Generation: Active & Passive. Advantages : - Less sensitive to doppler shifts. - The easiest to generate. - Disadvantages: - Has range-doppler cross coupling -> measurement errors. - Range sidelobes are high -> weighting required -> 1 -2 d. B loss in SNR. 13
5 - NLFM Waveforms : - Eqn. : - Types: Symmetrical & Asymmetrical. - Advantages : - Very low range sidelobes. - For tracking systems. - Disadvantages: - Complex. - The limited developments. 14
6 - Phase-coded Waveforms : - Types : binary & polyphase. - Codes: Barker, P-codes. - Advantages : - low range sidelobes. - Preferred in jamming conditions. - Disadvantages: - Poor resolution in presence of distributed clutter. - The implementation is more complex than that of LFM. 15
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* Matlab Code: 17
* CW Code: 18
* LFMCW Code: 19
* LFMCW Code: 20
* NLFM Code: 21
* Uncoded Pulse: 22
* References : - Skolnik, Radar Handbook, 2 nd Ed. , Mc. Graw-Hill, 1990. - Barton & Leonov, Radar Technology Encyclopedia, Artech House, 1998. - US Navy, Aviation Electricity And Electronics, NAVEDTRA 14339. - Mahafza & Elsherbeni, MATLAB Simulations for Radar Systems Design. - Levanon & Mozwson, Radar Signals. 23
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