# aperture2swath

Swath extent for radar on ground plane

## Syntax

``[swlen,swwidth] = aperture2swath(r,lambda,d,grazang)``

## Description

example

````[swlen,swwidth] = aperture2swath(r,lambda,d,grazang)` returns the swath length and width for a radar system at its maximum extent, assuming a flat Earth.```

## Examples

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Estimate the maximum swath length and width of side-looking airborne synthetic aperture radar (SAR) operating at 16.7 GHz for a target range of 10 km. The radar has an aperture length of 3 m in the elevation dimension and of 4 m in the azimuth dimension. Assume a nominal grazing angle of ${30}^{\circ }$.

```lambda = freq2wavelen(16.7e9); R = 10e3; elaz = [3 4]; grazang = 30;```

Compute the swath length and the swath width.

`[swl,swwid] = aperture2swath(R,lambda,elaz,grazang)`
```swl = 119.6776 ```
```swwid = 44.8791 ```

## Input Arguments

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Range from target to antenna in meters, specified as a positive real scalar or a vector.

Data Types: `double`

Radar wavelength in meters, specified as a positive real scalar or a vector.

Data Types: `double`

Antenna dimensions in meters, specified as a positive real scalar or a 1-by-2 row vector.

• If you specify `d` as a two-element vector, the first element of `d` represents the antenna dimension in elevation and the second element represents the antenna dimension in azimuth.

• If you specify `d` as a scalar, `aperture2swath` assumes the antenna has equal elevation and azimuth dimensions.

Data Types: `double`

Grazing angle in degrees, specified as a scalar in the range [`0`, `90`].

Data Types: `double`

## Output Arguments

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Swath length and width in meters, returned as matrices.

• The rows of the swath length `swlength` correspond to the range values in `r`. The columns of `swlength` correspond to the wavelength values in `lambda`.

• The rows of the swath width `swwidth` correspond to the range values in `r`. The columns of `swwidth` correspond to the wavelength values in `lambda`.

The swath width also corresponds to the azimuth or cross-range resolution of a real aperture antenna.