Cartography

MICRODEM offers options for understanding cartography, map making, and map properties. These can be turned on using the Menu choices tab on the options form if they are not visible.

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

New Vector Map on the main toolbar, or  "File, Open, New Vector map" menu choice lets you open multiple projections at once.

Cartography menu choice when a map window is active.

  • Map distortion (pick Tissot locations):  
  • Datum (horizontal) shift:  works on any map with different primary and secondary datums. If the option is disabled, you must pick a different secondary datum.  Shows the shift as you roam, and displays full information when you double click. You can also plot the absolute value of the shift when you double click. To pick the font color and size, use the Font option on the Overlay menu.  You will get a datbase table for the selected points.   You can export the values to a database with the Export computations option.
  • Sunrise/sunset times: You can select what to plot, and the time zone to use for the times.
  • Magnetic variation values: using WMM model.  Export values to a database with Export computations option.
  • UTM grid to true north declination:
  • Horizontal earth curvature
  • Magnetic declination overlay: The length of the field lines are arbitrary and constant, but they align with the earth's magnetic field calculated using the WMM model.  You are responsible for drawing this on a map with true north to the top.  You can export the values to a database with the Export computations option.
  • True north lines
  • Magnetic north lines
  • Tissot indicatrix (grid): this works only on vector maps and shows the pattern of map distortion.
  • State plane coordinate system: pick the projecton (conformal conic or transverse Mercator) and then the zone to use, and the program will show the corners of the current map.
  • Latitudinal scalebars: scalebars on the right side of the map, at the top, middle, and bottom
  • LCC standard parallels
  • Map projection zones
    • MGRS/USNG 6x8 zones: uses NGA shapefiles
    • UTM 100K zones.  These are split at the 6x8 degrees boundaries.  Uses NGA shapefiles
    • Combined MGRS Polygons
    • US SPCS zones (requires that you have the shapefile in the correct location, c:\mapdata\database\carto\us_spcs\us_spcs_zones.shp)
    • DEMIX 10K Tiles
  • Export computations: saves a number of fields to a database on a regular grid, which you can plot.  This can be a better visualization than a smaller number of points
  • Grid spacing and rotation: you can see the spacing and the grid rotation angle, either for the corners and center, or for points spacing a specified number of pixels apart.
  • Earth rotation: rotate the map, with an option to color code it from a number of world data sets.  You can overlay the world outlines, with an option set on the "Vector Maps" tab of the options form.  Only available with stereographic, orthographic, and Lambert Azimuthal equal area projections
 

Map Overlays can show:

Map projection gallery. With the vector map choice, you can get a large number of projections. The default projection is a Mercator ellipsoidal; you can change this by right clicking, and then selecting the "Modify projection" menu choice. There may be problems blowing up some of the more exotic projections.

Cartography principles.

Last revision 9/14/2021