Open Vector Maps

Quick vector map: open single vector map with default projection and extent. The default is a Mercator projection; you can change it on the Directories tab of the options form.

Vector maps on the main toolbar, or  "File, Open submenu, New Vector map" menu choice brings up this form.


Projections (see Map projection gallery):

  • Only projections in bold should be used for detailed mapping.  The ability to blow up and subset the others varies; they are intended only for overall views of the earth, and teaching the basics of computer mapping.
  • Projections are divided by the geometric basis.

Central latitude and longitude. Set "override defaults" checkbox to modify these.

UTM zone (only affects UTM projection)

Tissot indicatrix: automatically draw distortion measures on the map. They will have a default radius in pixels.

h&k decimals: the number of decimals when you double click on the map and get the values for distortion. The default 2 works well for small scale maps where the distortion varies significantly; for large scale maps, 4 or even 6 may be more appropriate to show patterns of very small distortion.

Options to automatically add

  • MGRS zone
  • UTM 1:100K squares
  • Outlines: control display for global rivers, coasts, and boundaries.

Grayscale, subdue map 

Open multiple maps: allows selection of multiple maps, to compare projections.

Close form on opening a new map

User Projection: defined in PRJ file specified on the Directories tab of the Options form.  Default is a Mercator projection of the world.

Pick the LCC locality.  For other regions, open the map and then Modify projection

OK: open selected maps.

 Change the projection by:

Buttons on map toolbar, especially key buttons.

Use spcified projection to display a DEM.

Last revision 11/1/2017