# IneichenClearSkyModel

Generates the clear sky irradiance using Ineichen and Perez model 2002

## Contents

- Syntax
- Description
- Inputs
- Outputs
- Example

## Syntax

    GHI = IneichenClearSkyModel(times,latitude,longitude,elevation,Lz);

## Description

Function to generate the clear sky global horizontal irradiance for a given time period and location using the SoDa Linke Turbidity maps

## Inputs

- `times` - matlab datenum (Example: datenum(2011,2,23) ), can be an array of times
- `latitude` - site latitude (decimal degrees)
- `longitude` - site longitude (decimal degrees) (negative for West)
- `elevation` - site elevation (meters)
- `Lz` - standard times zone meridian (120 for PST, 105 for MST, 90 CST, and 75 for EST). To find the time zone meridian, just take GMT offset and multiply by -15. (e.g. Eastern time is GMT -5hrs, so the meridian is (-5)*(-15) = 75 degrees.
- Linke Turbidity images in a folder ('LinkeTurbidity'), images obtained from (http://www.helioclim.org/linke/linke_helioserve.html)

## Outputs

- `GHI` is an array of GHI values for each time in array times

## Example

Generates the 1-minute GHI profile for Albuquerque for the first week in April, 2011.

    times = datenum(2011,4,1):1/(24*60):datenum(2011,4,8);
    GHI=IneichenClearSkyModel(times, 35.04, -106.62, 1617, 105);
    plot(times, GHI,'LineWidth',2); datetick('x','mm/dd','keeplimits','keepticks');
    set(gca,'FontSize',12,'FontWeight','bold');
    ylabel('GHI (W/m^2)','FontSize',12,'FontWeight','bold');
    xlabel('Time','FontSize',12,'FontWeight','bold');