# pvl_extraradiation

Determine extraterrestrial radiation from day of year

## Contents

- Syntax
- Description
- Inputs
- Outputs
- Example
- References
- See Also

## Syntax

`Ea = pvl_extraradiation(doy)`

## Description

Determine the amount of extraterrestrial solar radiation.

## Inputs

- `doy` - an array specifying the day of year. Valid values are >=1 and <367.

## Outputs

- `Ea` - extraterrestrial radiation present in W/m^2 on a surface which is normal to the sun. `Ea` is of the same size as the input `doy`.

## Example

Calculate extraterrestrial radiation for doy = 60;

    Ea = pvl_extraradiation(60)

    Ea =

       1.3922e+03

## References

[1] http://solardat.uoregon.edu/SolarRadiationBasics.html, Eqs. SR1 from [2] and SR2 from [3].

[2] Partridge, G. W. and Platt, C. M. R, Radiative Processes in Meteorology and Climatology, 1976.

[3] Duffie, J. A. and Beckman, W. A., Solar Engineering of Thermal Processes, 2nd edn. J. Wiley and Sons, New York, 1991.

## See Also

`pvl_date2doy`

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