Map GPS Coordinates - GPS Map Coordinates ... - Global Mapper

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Global Mapper User's Manual
• Use 3D Line Features as Constraints (i.e. Breaklines) - If this option is checked, any line and area
features that have elevation values associated with them will be treated as constraints/breaklines. This
will ensure that elevation values along the line/area boundary will be consistent with the elevation that
should be along the line.
• Flatten 3D Area Features - If you have any area/polygon features with elevation in the selected layers
that you are gridding, they will be treated as flattened areas rather than just additional 3D data
points/constraints. This allows you to create flattened areas like lakes and also nice terrain surfaces
from things like building models. If only 3D area features are present, any grid locations outside of
the areas will be marked as invalid, otherwise the grid locations within areas will just be flattened to
the area heights and the remainder of the grid will be generated as usual.
• Taper 3D Area Features Using Curve Value - If you have any area/polygon features with elevation in
the selected layers that you are gridding and you also checked the option to flatten 3D area features,
the taper option allows you to specify that rather than making the areas absolutely flat, the edges
should be tapered with the area elevation existing near the centroid of the area and the elevation
applied for the area dwindling to zero as you reach the area edge. The curve value specifies the
exponent to apply to the percent distance a sample location is between the area centroid and the area
edge to adjust the height applied at that location. Values less than 1 will make the edge steepness
progressively greater (i.e. flatter at the middle, then steep edges), while values larger than one cause
the steepness to be near the area centroid and flatter towards the edges, while a value of 1 provides for
a linear taper. For example if you want to simulate a sand bunker for a golf course, a value of around
0.5 provides a decent simulation of a bunker.
• Ignore Zero Elevations - If checked, this option will cause any features with an elevation value of zero
to be ignored. This is useful if you have a data set where features with no known elevation are marked
with an elevation of zero.
• Save Triangulated Network (TIN) as a Vector Layer - If checked, this option will cause a separate
vector layer with area features for each 3D triangle created as part of the triangulation and gridding
process. This is known as the TIN surface.
• Heights Relative to Ground - If you check this option, all elevation values from the selected vector
layers will be treated as relative to the height of any loaded underlying terrain surface (like a DEM).
This is very handy for doing things like creating building models where you just know the building
height above ground and not above sea level.
• Fill Entire Bounding Box Instead of Just Inside Convex Hull - If you check this option, the generated
elevation grid will contain valid values filling the entire bounding box specified for the gridding
operation. Otherwise, the valid values will only fill out to the convex hull polygon of the data being
gridded.
• Export Grids Directly to Global Mapper Grid Files - If checked, this option will cause the generated
elevation grid file(s) to be directly exported to Global Mapper Grid (GMG) files. This is useful when
you are triangulating and gridding a very large collection of data and also using the Gridding tab to
split the operation into smaller pieces. By directly exporting the results to GMG files you can create
elevation grids that normally would not all fit into memory.
Pressing the Metadata... button displays metadata for the selected overlay. The actual metadata dialog
displayed depends on the type of the selected overlay. The metadata dialog for a SDTS DLG is shown below.
Map GPS Coordinates - GPS Map Coordinates - GPSCoordinates Map 134