How to address Drone2Map GCP warning? Points interpolated from 2m DEM

565
1
06-18-2019 10:03 AM
MaribethMilner
New Contributor III

I'm trying to process ag field data for which I don't have control points.

- Identified relatively stable areas in a 2m resolution USGS DEM (presumably NAVD88)

- ArcGIS interpolated elevation values for points located at those ~stable areas

- Created csv file of x,y,z values

- Imported the file to D2M and a yellow triangle warning appeared by each entry

- Report says the points aren't being used.

- Used default gravity model for CGPs.

I've attached a report from one of the more "successful" runs that shows a fictitious deep hole at the east edge of the field.

The USGS DEM suggests a road used to run along (and inside) the east field's edge. The linear feature is slightly depressed from the rest of the field. I positioned 3 GCPs along that likely road to assist the analysis... but the GCPs weren't used.

Second, related question... could such a linear feature "confuse" D2M's algorithms?

0 Kudos
1 Reply
CodyBenkelman
Esri Regular Contributor

Maribeth

it sounds like you did not link the control points to specific locations in multiple images.  GCPs have known ground coordinates, but can't be used until the locations of those points are identified in at least some of the images (raw image coordinates).

see https://doc.arcgis.com/en/drone2map/projects/manage-gcps.htm

Cody

0 Kudos