Design Block Boundaries

Design Block Boundaries tool creates shape elements that can be used as block boundaries for a TerraScan project. The block boundary creation can start from line or shape elements. If points are loaded in TerraScan, the tool can also compute the amount of points inside each block boundary. The line elements used as starting elements…

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Display by elevation difference tool (dZ or DeltaZ)

The elevation difference tool will display, or generate images, based upon the settings that you select. For display those settings are located in the LAS properties -> Symbology -> Delta Z tab. The colors used by default usually indicate a good fit with green and a mismatch in red. Hence, open terrain areas generally appear…

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TerraMatch Airborne Laser Data

Calibration workflow TerraMatch can be used to solve the mirror scale parameter and the misalignment between the laser scanner and the inertial measurement unit (IMU). The misalignment is expressed as heading, roll and pitch angular correction values which need to be known for every laser scanner system. Different laser scanners may require additional calibration parameters…

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Fluctuating corrections with tie lines

Besides the correction of systematic shifts, tie lines can be used for applying corrections that change over time (fluctuating corrections, drifts). This is essential for correcting local drifts of the trajectory solution which occur, for example, if there is a failure of GPS signal during a flight or drive. Fluctuating corrections are the most important…

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TerraMatch Mobile Laser Data

Calibration workflow The task of mobile scanner calibration includes solving misalignment angles heading, roll and pitch for each scanner in a system. Misalignment issues are visible in the point cloud as differences between points of different drive paths and points of different scanners. The misalignment is more and more noticeable in the data the longer…

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RMSE and Minimum Contour Interval

The latest ASPRS Positional Accuracy Standards for Digital Geospatial Data shows the correlation between vertical RMSE and contour interval. The updated ASPRS standard uses accuracy based upon the RMSE (Root Mean Square Error) at the ground scale. The ASPRS Accuracy Standards for Large Scale Maps from 1990 used RMSE, however the difference comes in how the standards represent the accuracy…

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Process Flightlines Separately

Within the Macro Dialog when should a user check the option to process flightlines separately? A user would want to check this option when classifying ground for the following scenarios: Surface Matching If the option is not checked when ground is classified for surface matching, then the surface matching routine will converge but the corrections…

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Point Cloud Statistics Extractor CRS Codes

The results of extracting the LAS header information from the Point Cloud Statistics Extractor or LDDump may contain EPSG, GeoTIFF or other codes for coordinate systems, datums, units, etc. For GeoTIFF tag or codes: http://geotiff.maptools.org/spec/geotiff6.html#6.3.1.3 In here you’ll find for example the codes used for Linear Units: Linear Unit Values (See the ESPG/POSC tables for…

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Smooth Corner Vertex Spacing

The smooth corners contour option in LP360 is basically a choice between drawing contours as line strings or drawing them as curves. The Smooth Corner Vertex Spacing parameter is the number of vertices to be added between the existing vertices that are found where the contour crosses the triangle edge. Those vertices on the triangle…

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