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

Global Mapper User's Manual
• Nearest Neighbor - simply uses the value of the sample that a location is in. When resampling or
reprojected an image this can result in a stair-step effect, but will maintain exactly the original
elevation values of the source file.
• Bilinear Interpolation - determines the value of a new sample based on a weighted average of the 4
samples in the nearest 2 x 2 neighborhood of the sample in the original image. The averaging has an
anti-aliasing effect and therefore produces relatively smooth edges with hardly any jaggies.
• Bicubic Interpolation - a more sophisticated method that produces smoother edges than bilinear
interpolation. Here, a new pixel is a bicubic function using 16 samples in the nearest 4 x 4
neighborhood of the sample in the original image.
• Box Average (3x3, 4x4, 5x5, and 7x7) - the box average methods simply find the average values of the
nearest 9 (for 3x3), 16 (for 4x4), 25 (for 5x5), or 49 (for 7x7) samples and use that as the value of the
sample location. These methods are very good for resampling data at lower resolutions. The lower the
resolution of your export is as compared to the original, the larger "box" size you should use.
The Shader option allows you to choose which elevation shader is to be used for coloring the cell values
within this layer. By default, all gridded layers will share the elevation shader selected on the toolbar, but
there may be certain situations where you want to color one layer differently than the others and exclude it
from the loaded elevation range. One common example is a gridded layer that actually has non-elevation data.
The Alter Elevation Values tab (pictured below) allows you to modify how elevation values from the selected
layer(s) are interpreted, providing you a means to offset all of the elevations in the layer(s) by a given value
and to restrict the range of elevation values that are treated as valid.
Map GPS Coordinates - GPS Map Coordinates - GPSCoordinates Map 150