GCP Coordinate system

Jason_Wright · February 6, 2018, 6:55pm

I am trying to add GCPs to my project using data collected from a GPS sytem that uses NAD-1983 Datum, and editing the datum while importing thre GCP file. My project appears in the correct location on the map, but my GCPs are landing a great deal away, in the ocean. Please help.

Jaakko_Laihola · February 7, 2018, 5:27am

Hi Jason

Have you tried to change the Coordinate Order?

Aaron_Woods2 · February 11, 2018, 1:54am

Hi Jason.

Could you provide a copy of your quality report? A bit more information about your selected coordinate systems would be helpful. Pix4D uses there different ones,

Image Coordinate system determined by info in image EXIF header files, (i.e.Geotags from drone camera)
GCP Coordinate system. Coordinate system of Ground Control Point (GCP) data provided to Pix4D.
Image output Coordinate System. - Can be set by user, or defaults to GCP Coordinate system.

Reading the quality report would reflect the values chosen.

Best Wishes,

Aaron Woods

Jason_Wright · February 12, 2018, 10:35pm

Aaron,

The entire report is too large, is this what you were looking for?

Aaron_Woods2 · February 13, 2018, 5:22pm

Hi Jason,

The information you posted appears to be identical to your initial post.

A couple of support articles that may be helpful to you are:

How to select / change the Image / GCP / Output Coordinate System

How to add / import GCPs in the GCP/MTP Manager

How are you entering the GCP data? Your report only lists information on the Image Coordinate System and Output Coordinate System, but doesn’t list any GCP Coordinate System.

Jason_Wright · February 13, 2018, 5:43pm

Aaron,

The GCPs are being imported using the GCP/MTP Manager, using the same coordinate system as you see assigned to the output.

Nicholas_Stephens · February 15, 2018, 4:32pm

Jason,

A lot of surveyors tend to truncate their coordinates. Ensure that your GCP coordinates are not truncated. This may account for them showing up in the ocean.

Jason_Wright · February 19, 2018, 3:23pm

Nicholas,

If the coordinates are truncated, what is the work around to bring them back into the project area?

Nicholas_Stephens · February 20, 2018, 5:02pm

Truncating is just when the surveyor takes off the first few digits of the coordinates to make them less unwieldy. You can just add the appropriate digits to the beginning.

Example: if coordinates are 123456.789 but yours show up as 23456.789 just add the 1 to the front of the coordinate listing.

I noticed truncated coordinates on one of my projects and simply changing the GCP coordinates fixed the problem. I hope that is all that it is.