# value

Radar cross-section at specified angle and frequency

## Description

returns the value, `rcsval`

= value(`rcssig`

,`az`

,`el`

,`freq`

)`rcsval`

, of the radar cross-section (RCS) specified
by the radar signature object, `rcssig`

, computed at the specified
azimuth `az`

, elevation `el`

, and frequency
`freq`

. If the specified azimuth and elevation is outside of the region
in which the RCS signature is defined, the RCS value, `rcsval`

, is
returned as `-Inf`

in dBsm.

## Input Arguments

## Output Arguments

## Examples

## Algorithms

The RCS signature, is first linearly interpolated at the specified azimuth,
`az`

, and elevation, `el`

, view angles for the
provided frequencies, `freq`

. The interpolated signature is then used as an
expected value of a probability distribution that generates a signature pattern value
according to the RCS fluctuation model specified by the `FluctuationModel`

property.. `az`

and `el`

are specified in degrees and
are defined in the body frame of the pattern. `freq`

is in hertz.

If `FluctuationModel`

is `'Swerling0'`

, the returned
pattern value is a deterministic constant equal to the interpolated signature.

If `FluctuationModel`

is `'Swerling1'`

, the returned
pattern value is a random variable distributed according to an exponential distribution with a
mean value equal to the interpolated signature.

If `FluctuationModel`

is `'Swerling3'`

, the returned
pattern value is a random variable distributed according to a chi-square distribution with
four degrees of freedom and a mean value equal to the interpolated signature.

## Extended Capabilities

## Version History

**Introduced in R2018b**

## See Also

`rcsSignature`

(Radar Toolbox) | `toStruct`

| `tsSignature`