I use an Inspire 1 to do mapping. I usually just use the DJI pilot app to control the drone and do a manual flight path. I have tried using a new app from Mapping Made Easy that allows you to plan your flight path. The problem I keep running into is after adding my control points it is not changing my picture location from altitude to an elevation. My picture altitude is 300ft. off the ground, and my ground elevation is 330ft. After processing it my flight path is below my surface since its not changing the altitude. This does not happen when taking pictures manually with the DJI pilot app. Is there something I need to change in Pix4D when using this flight app or is it a setting in the app? Thanks
I should make that a little clearer. Once I dump the images into Pix4D and do the processing it will not change the altitude to an elevation.
Was an geo data capture in the image meta data?
This is an issue with the geotagged images from the inspire which geotags the image with the height above the ground. The P4d capture app creates a file that will correct the problem. Your other option is to edit the elevation in the EXIF data.
Yes the geo information is in there. What I can’t figure out is that it works fine when using the DJI app and doing it manually. Its when I use the Mapping Made Easy app where you can plan your flight path that it doesn’t work. When looking at the geo tags on the photos they do not look any different than the other ones. When flying it manually I have had a problem with getting a even accuracy. That is why I was trying to do it with this new app. As far as I know the P4D capture app will not work with the Inspire yet.
The only thing I see that is different is the dimensions. With the new app the photos are 4000x3000. With the DJI app the photos are 4000x2250.
The capture will work on an android device with the inspire. Are you using the iOS app?
Yes IOS app
I gave up and bought an Android Device. How many images do you have to process?
What are you setting your output coordinate system and are you using any of the geoids in P4D?
I’ve been using the arbitrary coordinate system to get it on our own local system. So that’s what I used when testing this new app as well.
Are you using ground control points with the basic editor?
Yes using around six control points in this project.
Ok, the only way you are going to get it to work is by using the basic editor and not the ray cloud editor to pick your ground control points. It will look funny, but it will work. What is the Z value of your GCPs compared to MSL?
Well what I usually do is mark each GCP twice in the basic editor, and then go to the raycloud and finish marking them. If you don’t mark them on two photos they wont show up in the raycloud. Its quicker to mark them in the raycloud since it finds all of the photos for you.
So you mark two points in the Basic and the do your initial processing and then mark in the ray cloud?
No I will bring in the photos and go ahead and do the initial processing. Then import my control point locations and mark two points in the basic. Then switch to the raycloud and finish marking the control points. Once they are all marked do a reoptimize, and generate a quality report. Then I go back to output coordinates and load the optimized. I can then finish processing the point cloud. For some reason when I do the initial processing with the photos from this new app it has the flight path at 300ft. elevation. The altitude I flew it at was 300ft. off the ground. So the automatic points it generates after initial processing end up at anywhere from 9ft. to -40ft. elevations. It should be changing the flight path to a 600ft elevation.
My control points range from 320ft. to 330ft. elevation. After I put them in and reoptimize it has my flight path at a 0 to -60 elevation. So it is under my control points and automatic points generated.
The issue is the photos are giving you the elevation above the ground and not MSL. The capture app accounts for this and most other apps do not. If your point cloud is on the correct datum, why do you care? You can fix it if it really bothers you by editing the EXIF data and adding your MSL height. I have actually observed the same issue with the capture app when people use the imaged without the P4D file generated by the app.