Storing and Exporting Viewsheds

Set the location for MICRODEM to save fans on the bottom of  fan properties selection window.

The names will be that of the fan selected on fan properties selection window.  If you leave it blank, the program will pick a name for you (and you will have a hard time finding the correct fan).

The program will store both a visible and a masked map, in GIF format.  These can be used to compute viewshed statistics.  Because the program actually does sub pixel computations (a lot of samples at the center of the fans, just one at the margins), it can compute three categories (fully visible, fully masked, and partial).  The two types of fan will use different colors, and the last part of the file name will be VIS or MASK.

For each fan, there will be two viewsheds, the visible and the masked.  For each there will be

1:1 map view should be used for maximum accuracy of the results.  At less than 1:1, it will go faster with less accuracy. Set the zoom factor to use for the on the viewshed algorithm form

These files can be displayed in ArcGIS.  You need the GIF and GFW files, and  a valid PRJ file.  To save fans or Export fan definitions for use in ArcGIS use the "Edit fans" choice from the popup menu and then pick "Report" and DBF table.

Export the fans to KML,but without easy re-import into MICRODEM.

Restore fans by picking GIF file from Overlay, World file images menu choice.  This option does not let you modify the fans.

You can also save the fans definition dBase table, and restore it with File, Load weapons fan menu choice.  This option lets you modify the fan parameters and redraw.

To create viewsheds from an existing file, which as a minimum must have LAT and LONG fields (NAME would be a good choice as well).  This lets you start from a file with known locations.

Last revision 3/2/2016