bw2rangeres

Convert bandwidth to range resolution

Description

example

rangeres = bw2rangeres(bw) returns the range resolution rangeres corresponding to the signal bandwidth bw. Range resolution gives the minimum range difference needed to distinguish two targets. The propagation is assumed to be two-way, as in a monostatic radar system.

example

rangeres = bw2rangeres(bw,c) also specifies the signal propagation speed c.

example

Examples

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Assume you have a monostatic radar system that uses a rectangular waveform. Calculate the range resolution obtained using a signal bandwidth of 20 MHz.

bw = 20e6;
rngres = bw2rangeres(bw)
rngres = 7.4948

Calculate the range resolution of a two-way sonar system that uses a rectangular waveform. The signal bandwidth is 2 kHz. The speed of sound is 1520 m/s.

bw = 2e3;
c = 1520.0;
rngres = bw2rangeres(bw,c)
rngres = 0.3800

Assume a monostatic radar system that uses a rectangular waveform. Calculate the range resolution for two signals with bandwidths of 10 and 20 MHz. Use a range broadening factor of 2.0.

bw = [10e6,20e6];
c = physconst('Lightspeed');
rngres = 1×2

29.9792   14.9896

Input Arguments

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Signal bandwidth, specified as a positive scalar. Units are in Hz.

Example: 300e6

Data Types: double

Signal propagation speed, specified as a positive scalar. Units are in m/s.

Example: 3.0e8

Data Types: double

Range impulse broadening factor, specified as a real scalar. Range broadening occurs due to data weighting or windowing for side lobe control. Range broadening is the ratio of the actual –3 dB main lobe width with respect to the nominal width. Typical window functions such as hamming or hann exhibit range broadening in the range of 1 to 1.5.

Example: 2.0

Data Types: double

Output Arguments

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Signal range resolution, returned as a positive scalar. Units are in meters.

Algorithms

The range resolution (in meters) for a rectangular pulse of bandwidth, bw, is c/bw/2, where c is the propagation speed. The range resolution broadening factor,b yields a range resolution of cb/bw/2.