GCPs for Photogrammetry: How Many Do You Need?

Host: Eric Andelin, Workflow Advisor at SimActive Inc.

Guest: Hayden Howard, Executive Vice President, CompassData Inc and Philipp Hummel Vice President, PLS, CFedS, CP at CompassData


Surveying and photogrammetry are complementary technologies. While either can be done without the other, they can both benefit from the use of the other. Aerial imagery and photogrammetry will always cover more ground than traditional ground-based survey. However, without ground-based survey, the absolute accuracy of a photogrammetry project cannot be defined. Photo identifiable ground control points (GCPs) are what allows the two technologies to come together. The positioning or physical location of GCPs and the quantity required for a project are all dependent on the accuracy desired, and the user’s confidence in supporting technologies. Hayden Howard and Philipp Hummel join our host Eric Andelin to discuss these topics.

Click here to register: https://hubs.ly/Q02p4K650

Attendees with learn the following:

  • Why do placement and size of GCPs matter
  • Why is distribution important
  • How other technologies such as RTK/PPK play a role
  • How many GCPs are required