bw2rangeres

Convert bandwidth to range resolution

Since R2021a

Syntax

``rangeres = bw2rangeres(bw)``
``rangeres = bw2rangeres(bw,c)``
``rangeres = bw2rangeres(___,'RangeBroadening',rb)``

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

````rangeres = bw2rangeres(___,'RangeBroadening',rb)` also specifies the range broadening factor `rb`.```

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 = bw2rangeres(bw,c,'RangeBroadening',2.0)```
```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 (c × b)/(bw × 2).

Version History

Introduced in R2021a