Shadows

This transform computes the amount of shading on the land based on the location and heights of things (typically trees) specified in an input raster.

The algorithm uses the position of the sun to project a triangular shadow onto the ground based on the height of each item. The sun position can be swepth through a number of months and/or days for a specific year. The amount of shading is then accumulated into the final output raster.

The times entered into the settings dialog are acutal local times based on the local time zone.

Content Tab

Settings Tab

Year: The year to produce shadows for.

First Month: The first month to examine. Values are 0 for January, 1 for February, etc.

End Month: The last month to examine.

Start Hour: The first hour to examine in a 24 hour clock where 0 would be midnight, 12 would be noon, etc.

End Hour: The last hour to examine in a 24 hour clock where 0 would be midnight, 12 would be noon, etc.

First Day Of Month: The first day of the month to examine, with 1 being the very first day in the month.

End Day Of Month: The last day of the month to examine.

Minute Increment: The number of minutes to add between each successive shadow that is produced. 1 will produce very accurate shadows but will take a great deal of time for large rasters.

Time Zone: The time zone that the location is in. -6 is for Colorado, etc.

Elevation: The average elevation of the raster.

Latitude: The latitude to use to compute shadows. All points will use this latitude value.

Longitude: The longitude to use to compute shadows.