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Laser Sketch Laser Sketch is an ESRI ArcMap/ArcScene extension that enables the real-time mapping of points from a laser range finder or a total station to their correct position on a photograph. Laser Sketch uses the camera lens distortion parameters to correctly place the point measured by the laser instrument. The lens distortion parameters can be obtained using free ware programs or commercial programs such as MatLab® and Photo Modeler®. The distortion parameters need to be measured only once for each camera/lens combination. The parameters are saved in the Laser Sketch directory on the laptop. The laptop is connected to a laser instrument that has a traverse and elevation capability. We currently have drivers for some Topcon® and some Laser Atlanta® instruments. A photograph of the target area is taken with the camera and loaded into Laser Sketch. Four tiepoints are selected between the target and the photograph. A graphic marker is placed in the photograph and the XYZ location of the point is measured with the laser instrument. After the four tiepoints are captured, the 3D to 2D transformation parameters that relate the target to the photograph are calculated. All subsequent points that are shot with the laser instrument are plotted on the photograph in their approximately correct position. Accuracy of less than two pixels in placement of the points is easily achieved with a total station.
The resulting points can be
displayed in 3D mode in an ArcScene window in Laser Sketch. The points can be
converted into 3D polylines and 3D polygons. For geological outcrops, the point
based tools in GeoAnalysis Tools can be used to analyze the orientations of the
features which have been sketched. Electric tower created from digitized 3D points using Topcon Total Station and Laser Sketch program
Work Flow
Software Gallery
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