Creating Control Points Tutorial - ngageoint/voxel-globe GitHub Wiki
To create control points, a csv file must be generated in this format. The source can come from surveyors, common GPS, advanced DGPS, or LiDAR. This tutorial will cover an example using a Rhode Island LiDAR and the Windows Application QTReader to create a control point file.
Go to the RIGIS page and download the 19_02984632_las file (47.3 MB). Extract the las file and open it in QTReader
Open the LAS file in QTReader.
- Use Click and Drag to rotate
- Right Click and Drag to pan
- Mouse wheel to zoom in and out
Move over to some of the downtown buildings, and create some Markers (Thumbtack Icon)
When you have created all of your markers, (their names can be changed by the Markers->Edit Marker... menu), save the markers to disk using the Markers->Save Markers... menu. Select All, Choose the ASCII Format, then click OK, and save the markers.
Use a script like this gist to convert the points to the csv format. Then follow the Control Point Upload Tutorial to upload the control points. See the Tie Point Creator Tutorial for further information
Example Marker File:
Geodetic (World Geodetic System 1984)
Name, X, Y, Z, R, G, B
Super_West_Corner,41.824551000 -71.411548000 60.680 255 0 0
Super_South_Corner,41.824168000 -71.411070000 60.290 0 255 174
Super_East_Corner,41.824398000 -71.410738000 60.570 255 0 161
Super_North_Corner,41.824783000 -71.411220000 60.440 0 255 12
Equivalent example CSV file:
Super_West_Corner,4326,-71.411548000,41.824551000,60.680
Super_South_Corner,4326,-71.411070000,41.824168000,60.290
Super_East_Corner,4326,-71.410738000,41.824398000,60.570
Super_North_Corner,4326,-71.411220000,41.824783000,60.440