Skip to content

Creating Control Points Tutorial

Andy Neff edited this page Oct 28, 2016 · 2 revisions

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)

images/qtreader.png

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

Clone this wiki locally