# rangeres2bw

Convert range resolution to bandwidth

## Syntax

``bw = rangeres2bw(rangeres)``
``bw = rangeres2bw(rangeres,c)``
``bw = rangeres2bw(___,'RangeBroadening',rb)``

## 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`.```
````bw = rangeres2bw(___,'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 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 = rangeres2bw(res,c,'RangeBroadening',2.0)```
```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.

## Version History

Introduced in R2021a