Project:

Radar Waveforms Generation & Analysisby Matlab

 

Prepared for:

Dr. Mohammed OudaIslamic University of GAZA (IUG)

Done By:

Jalal Al-Roumy 120050239Akram Abu-Raida 120061458

*Outlines:

Choice importance . Factors of choice. Classification. Pulse shapes. Major types. Matlab Codes. References.

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* 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.

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*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.

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*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.

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* The most popular pulse shapes :

- Sinusoidal.- Rectangular.- Gaussian.- Triangular.- Sawtooth.- Exponential.

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*Pulse Shapes:

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*Main Waveforms:

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1 -CW Waveforms:

- Eqn. : Et = E0 cosw0t.

- 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.

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2 -FMCW Waveforms:

- Eqn. : f(t) = f0 + 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 dB loss in SNR.

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3 -Simple Pulse:

- Eqn. : Et = E0 cosw0t. (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.

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4 -LFM Waveforms:

- Eqn. : f(t) = f0 + 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 dB loss in SNR.13

5 -NLFM Waveforms:

- Eqn. : - Types: Symmetrical & Asymmetrical.

- Advantages :- Very low range sidelobes.- For tracking systems.

- Disadvantages:- Complex.- The limited developments.

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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.

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*Matlab Code:

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*CW Code:

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*LFMCW Code:

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*LFMCW Code:

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*NLFM Code:

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*Uncoded Pulse :

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*References: - Skolnik, Radar Handbook, 2nd Ed., McGraw-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.

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