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# sarchirprate

Azimuth chirp rate of received signal for SAR

Since R2021a

## Syntax

``acr = sarchirprate(r,lambda,v)``
``acr = sarchirprate(r,lambda,v,dcang)``

## Description

example

````acr = sarchirprate(r,lambda,v)` computes the nominal azimuth chirp rate at which the azimuth signal changes frequency as the sensor illuminates a scatterer.```

example

````acr = sarchirprate(r,lambda,v,dcang)` specifies the Doppler cone angle that identifies the direction towards the scene relative to the direction of motion of the array.```

## Examples

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Compute the azimuth chirp rate of received signal for a side-looking airborne synthetic aperture radar (SAR) operating in broadside at a wavelength of 0.03 m with a sensor velocity of 100 m/s for a target at 10 km. The sensor illuminates the scatterer at a Doppler cone angle of ${90}^{\circ }$.

```lambda = 0.03; R = 10e3; v = 100;```

Compute the azimuth chirp rate.

`azchirp = sarchirprate(R,lambda,v)`
```azchirp = 66.6667 ```

## 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`

Sensor velocity in meters per second, specified as a positive real scalar.

Data Types: `double`

Doppler cone angle in degrees, specified as a scalar in the range [`0`, `180`]. This argument identifies the direction toward the scene relative to the direction of motion of the array.

Data Types: `double`

## Output Arguments

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Nominal azimuth chirp rate in hertz per second, returned as a matrix. The rows of `acr` correspond to the range values in `r`. The columns of `acr` correspond to the wavelength values in `lambda`.

## Version History

Introduced in R2021a