rangeres2bw

Convert range resolution to bandwidth

Description

example

bw = rangeres2bw(rangeres) returns the signal bandwidth bw corresponding to the range resolution rangeres. Signal bandwidth gives the maximum bandwidth needed to distinguish two targets in range. The propagation is assumed to be two-way, as in a monostatic radar system.

example

bw = rangeres2bw(rangeres,c) also specifies the signal propagation speed c.

Examples

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Assume you have a monostatic radar system that uses a rectangular waveform. Calculate the signal bandwidth needed to obtain a range resolution of 25 m. Use the default speed of light.

rangeres = 25.0;
bw = rangeres2bw(rangeres)
bw = 5.9958e+06

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

rangeres = 1;
c = 1520.0;
bw = rangeres2bw(rangeres,c)
bw = 760

Assume a monostatic radar system that uses a rectangular waveform. Calculate the bandwidths of two signals with range resolutions of 1 and 10 meters. The range broadening factor is 2.0.

res = [1.0,10.0];
c = physconst('Lightspeed');
bw = 1×2
108 ×

2.9979    0.2998

Input Arguments

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Range resolution, specified as a positive scalar. Units are in meters.

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 bandwidth, returned as a positive scalar. Units are in Hz.

Example: 300e6

Data Types: double

Algorithms

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