This menu option for a map window allows
calculation of various parameters and graphics.
Area: outline the desired area. You do not have to close the
area. Select either with stream or point
digitizing, whichever you have active.
Distance: double click on points and get the distance between
them and the cumulative distance. This option remains
active until you decline to add another point to the
- Geodetic bearing
- Bearing: calculate bearing (angle)
between two points using the Vincenty (1975) geodetic algorithm. This will
use a geographic angle (from true
north). The line and bearing of the two ends will be plotted on
- Elevations/ grid values
- Point classification: Ridges/valleys
- Peaks, pits, and spires
- Building edges/roofs (requires DSM as current grid)
- Peak/island area
plot longitudinal profile of a stream valley by
clicking on points.
- Extract points:
Digitize the profile, and then pick the point separation interval, and
whether you want the points to be exactly on DEM grid points or
interpolated between them. Creates a
- Area of single color: This will be done at screen resolution.
If the map covers a large area with a geographic projection, this will be
- DEM/Grid area: uses the DEM or grid, with the potentially
variable spacing in the x direction. This will use all non-missing
pixels in the grid, so if you want to find areas meeting a particular
criterion, edit the grid first and mark missing points that do not match
- Point parameters
- Offset: enter a distance and up to 5 bearings, and the
computer will plot the location relative to a starting
point that you select.
- Rhumb line
- Age from depth (MGT): calculate age from the depth. This
assumes normal seafloor subsidence, with a ridge depth of 2.5 km. It will
give approximate results, but will not be valid on land, continental shelves
or slopes, or near trenches. After selecting this option, the calculated age
will appear at the bottom of the map when you roam with the mouse until you
select another option that employs the mouse.
- Derivative grid
- Topographic grain
- Average by latitude: plot a graph with latitude on the y axis, and the
average value in the grid on the x axis.
- Flight coverage
- Map window corners--get a text box with the map window corners,
and the center.
- Point categories
- Image palette
- PLSS from Lat/Long--click on map, and get the PLSS location
- PLSS from Lat/Long keyboard entry
- Lat/Long from PLSS
- US properties (requires that
shapefiles be correctly located)
- 7½' Quad Names
- Roaming Z values from 2d grid: pick a second open grid, and while you
roam, its z value will appear in in the status bar. This will show
only that single DEM, instead of all DEMs (which might not fit if you enough
open and a small monitor).
- Where is? (keyboard)
- RGB values
- Max/mean/min grids from point data:
- Vegetation density layers
- Abort current operation
Last revision 6/7/2022