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 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 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
- LCC standard parallels
- Map projection zones
- US SPCS zones (requires that you have the shapefile in the correct location,
c:\mapdata\database\carto\us_spcs\us_spcs_zones.shp)
- MGRS/USNG 6x8 zones
- UTM 100K zones. These are split at the 6x8 degrees boundaries
- 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 point
- 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
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Map Overlays can show:
- MGRS grids zones:
6x8 degree MGRS zones. The first part,
a number, is the UTM zone between 1-60, and the second
part, a letter, is a latitude band.
- MGRS 100K squares:
the two letter designator for 100,000 m squares. These will
behave much like a Tissot indicatrix; if the map is conformal, these
should be squares, and if the map is equal area, they will all be the same
size.
- Tissot indicatrices: show
patterns of map distortion.
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 8/30/2011