Can’t find my coordinate system. Texas south central state plane 4204

[Apavlicek]

I’m trying to convert my exif data from my p4pro to match my the coordinates that my gcps where shot in. Nad83 Texas south central state plane 4204. Any help which one it is. I found something similar but I’m lacking 4204

[Alexey Pasumansky]

Hello Apavlicek,

Have you tried to use EPSG::2278?

[Apavlicek]

That doesn’t work. After I select epsg 2278 and then click ok InThe reference setting the cameras get all scrambled

[Alexey Pasumansky]

Hello Apavlicek,

The provided information, unfortunately, is not sufficient to understand what is wrong.

If you have source coordinate data for the cameras in WGS84 system and would like to align them with the markers' coordinate in another system, then you cold do one of the following:
- after adding images or aligning the photos use Convert button on the Reference pane toolbar to transform the coordinates of the cameras to another system, then load markers' coordinates in the same system,
- in the Reference pane settings select chunk's coordinate system (the most top line) according to the markers' system and enable separate system for the cameras to set it to WGS84.

Having the coordinates in WGS84 for the cameras and setting the coordinate information for the cameras to anything different without preliminary coordinate conversion would clearly lead to the incorrect result.

[PROBERT1968]

When I read your question. My question to you is
 ?

What do you mean convert your exif data ?

Can you provide more details on it ? Because it does not provide excatly clearly to me...

The EXIF you have should have provide you the coordinates for your area. Have you checked on it to make sure they are in correct projection ?

Take a look at here and there are comments here about that state plane :  https://epsg.io/102740

It could be why it doesn't work.  Maybe change it to WGS 84 like what Alexey is suggesting to you

[Apavlicek]

Alexey

Yes that is what I’m trying to do.  The coordinate data for the images from my p4pro are in wgs84.  My ground control points were shot in Texas south central state plane 4204. After I import the photos I click on the convert button in the reference pane and try to select the correct coordinate system. After I click ok in that window the blue dots in the model window are no longer arranged In rows like when the photos were taking. I stopped at that point. Maybe I’m doing something in the wrong order.

[Alexey Pasumansky]

Hello Apavlicek,

Can you please send export the coordinates of the original camera locations in WGS84 system via Reference pane -> Export button and send to to support@agisoft.com or add as attachment here (if the coordinate data is not sensible)?

[Apavlicek]

I got it figured out now. I wasn’t hitting the convert button. I was hitting the wrong button my apologies. I’ve now uploaded
my control points, but now I ran into a snap with filter markers by photo.   Whenever I clicked filter markers by photo it doesn’t  display any photos or marker.   The photo pane is blank?   Any ideas

[Alexey Pasumansky]

Hello Apavlicek,

Is it possible that camera locations altitude is lower that markers' altitude in the Reference pane? It may happen if the original altitude information from the image EXIF tags doesn't correspond to height above WGS84 ellipsoid.

[Apavlicek]

Yes the cameras location is lower than the markers. If I zoom out in the model pane I can see my markers, but then my model is so small I can’t see it

[Dave Martin]

Apavlicek - I don't use DJI for photogrammetry, but I know there is a well-known issue with the elevation stored by DJI, it is the height above takeoff. Have a search on here of 'DJI height' and you'll find plenty of threads and fixes.

Dave

[Alexey Pasumansky]

Yes the cameras location is lower than the markers. If I zoom out in the model pane I can see my markers, but then my model is so small I can’t see it

You can use the following script to add the fixed altitude value to all the camera locations in the Reference pane in order to bring them in accordance to the control points:
https://github.com/agisoft-llc/photoscan-scripts/blob/master/src/add_altitude_to_reference.py

[Apavlicek]

I’m new to scripts or python, and haven’t been able to get it to work. Would doing one of the following be a alternative?

Adjust the accuracy settings for ground control points and camera locations.
If you enter a very large number for camera accuracy (Photoscan default value is 10m) and a low number for marker accuracy (default is 0.005m), then the optimisation and height of the model will mainly depend on the Z value of your your ground control points/markers.

Uncheck all images/cameras in the reference pane so Photoscan will ignore their locations during Photo alignment and only use GCPs.

[Alexey Pasumansky]

Hello Apavlicek,

As an alternative you can export all the source values from the Reference pane for the cameras to the text file, then in Excel, for example, add the same fixed number to the altitude column, and import the coordinate information to the Reference pane ro substitute the EXIF data.

The approach that you are referring to assumes that the marker projections are already placed on the images. In your case, as far as I have understood, you were not yet been able to place any projections, since the markers are "floating" above the surface and even cameras.

[Apavlicek]

Yes you are correct on what you understand.

 I will try to export to excel. How do I determine what the fixed altitude is that I need to changed it to in excel.