Correcting Coordinate system

So when starting out using PIX4d I just did things to experiment and didnt totally care about what coordinate systems my things were in. On one sample item I was doing as a demo the project was output in NAD83 PA S in meters, captured my GCP’s that same way. Then I imported in to Survey and marked up lots of stuff. Now that I wrapped my head around how to capture correct coordinates and how to transform correct in mapper, I’m trying to see if I can somehow correct the one survey project I marked lots of things up in.
So is there a way to either re-import a file into survey to use correct coordinates and still have it keep my markups? My client wants everything in PA state plane SF. I think if I just switch everything over that in survey it totally then has wrong coordinates because like the text says, it wont do any transforming of the data.
So whats the best way to possibly fix this one projects coordinate system to display correct and be correct ? Thanks

Hi @kevin.sauerwald,

You should be able to modify the Coordinate Reference System (CRS) in PIX4Dsurvey itself.
I suggest you first create a fake test project with PIX4Dmapper using NAD83 PA S, open it with PIX4Dsurvey, add your markings, and then convert to PA state plane SF and check the results.

(edit: this does not work)

Can you please show me a screenshot of the warning message you are seeing and what procedure you followed?

Daniele

Thanks Daniele
So here is my GCP in Meters NAD83(2011) / PA S, captured from my GNSS receiver at top


As you can see when I point to my GCP the coordinates are ok. So now I want all this to be in Survey feet and adjust my Vertical to be correct also.
So when I go to change the coordinate system from bottom left to be what I want.

It just changes the units, doesnt change it over to actual computed survey feet , which the little note at the top of the box indicates.
image
Values are totally the same as last time, just unit change

So what I need to know is how do I fix the coordinate system, I assume I might need to re-upload a point cloud again from mapper ? I want to keep my work with the layers I added to everything but switch out the point cloud Northing, Easting and elevation to be survey feet.
Can you do that ?

Hi @kevin.sauerwald,

Thank you for the clear explanation and screenshots.
These are very helpful. This shows that it is not possible to do what I suggested in my previous post. I have edited it to avoid confusion.

I’m in direct contact with the product team and will see if there is any workaround for you. I will keep you posted.
Thank you for understanding.

Daniele

ok thanks… I assume there must be a way to reimport something to keep what was annotated but bring in a new point cloud with correct coordinates or something. I hope !!! ha ha

Hi Kevin,

You can try the following procedure:

  1. Export all the annotations using the current CRS, as SHP, ZIP SHP, or GeoJSON
  2. Create a new empty project in PIX4Dsurvey
  3. Import a .las file with the new/correct CRS in the new empty project; this will set the new/correct CRS
  4. Reimport all the annotations exported in (1.), the CRS transformation will be applied

Let me know how it goes.

Daniele

ok thanks… had to import like 5 times to get the height correct.
I exported the ZIP SHP from survey where I was in NAD88 2011 PA S Meters -height NAVD88 meters
reopened the project in mapper where I had my new coordinates in NAD83 2011 PA S Survey Feet with NAVD88 w/ 112.57 feet adjustment, then I sent to Survey
Then I did the import of the ZIP SHP data
it then asks what coordinate system this is in ( this I had to mess with to get correct)
I had to tell it I was pulling these in as NAD88 2011 PA S Meters and set the height in NAVD88 and set my above ellipsoid to 34.43 meters
then it finally laid it on correct.

Thanks

Hi @kevin.sauerwald

Can you please share the data with us?
If you don’t want to share the data with the entire community, feel free to open a support ticket here:
https://support.pix4d.com/hc/en-us/requests/new?

Daniele

Sorry, what data did you need me to share ? I thought I laid out what I did to make it work.

Hi @kevin.sauerwald,

Yes, I’m happy to hear that you made it work.

However, you also mentioned that

so I was wondering if there was anything we could improve on our side to make the procedure more seamless.

Let me know what you think.

Daniele

I think it would be great if Pix4D Survey would do the calculations when you switch coordinate systems, that would make it real easy.

Hi @kevin.sauerwald,

I understand your concerns and I have shared your request with the product team.

In the meantime, PIX4Dsurvey released a new version where it is possible to select a CRS for an empty project.

This means that you can now:

  1. Create a new project
  2. Select the desired the CRS
  3. Import the annotations/shapefiles. The transformations will be applied.

I hope this will make your workflow easier.

Let me know if this helps you.