Photogrammetry

[Hardwick1973]

I am keen to experiment with photogrammetry using my Mavic Pro.

I want to take a series of jpeg images at specific points along a pre-defined route. I will then stitch these together using Agisoft PhotScan.

I think the DJI app waypoint feature isn't going to cut it - does anyone have a better recommendation?

 

[Empie]

Drone Deploy, Precision Hawk.

 

[Hardwick1973]

Drone Deploy, Precision Hawk.

any view on which one is better?

 

[Empie]

Maybe Drone Deploy - I fly both at 120 metres / 400 feet & the pixel size seems to be fixed for both apps - both sub 5cm / 2 inches which is plenty fine enough for my purposes - however DD pixels are slightly larger than in PH - with the subsequent ramifications on memory required. I haven’t paid anything for either, so maybe having a reduced experience. Also on the last flight I did with PH the through the camera view was garbled (though photos were captured as normal). For both I need to draw in a polygon larger than the area required & ensure the edge areas I want will be in at least 2 photos (given the photo overlap) in order to get 3D information right to the edges.

I just looked at the AgriSoft site & those processed outputs seems similar to what are available on the www sites for the 2 apps I use.

 

[Hardwick1973]

Maybe Drone Deploy - I fly both at 120 metres / 400 feet & the pixel size seems to be fixed for both apps - both sub 5cm / 2 inches which is plenty fine enough for my purposes - however DD pixels are slightly larger than in PH - with the subsequent ramifications on memory required. I haven’t paid anything for either, so maybe having a reduced experience. Also on the last flight I did with PH the through the camera view was garbled (though photos were captured as normal). For both I need to draw in a polygon larger than the area required & ensure the edge areas I want will be in at least 2 photos (given the photo overlap) in order to get 3D information right to the edges.

I just looked at the AgriSoft site & those processed outputs seems similar to what are available on the www sites for the 2 apps I use.

thanks - which apps do you use and what's your workflow?

 

[Empie]

I set up the area to be captured on desktop via the www site for DD (I think in PH the area has to be set up in the app - i.e. no desktop option). In the former if going to be outside data coverage range, load up the area to the app before going out. I leave most settings as default - though set the altitude to that mentioned above (which is the maximum legal in my area). Align the flight tracks to be on the long axis of the area to minimise the turns & maximise efficiency. In consideration of the overlap % in the settings & the proposed flight track, expand the area if the edges you want won’t be in at least 2 images.

In addition to those 2 apps, I run DJI Go 4 to check the basic settings such as return to home altitude, compass calibration, etc. I then go over to one of the other 2 apps (am warming towards DD) to fly.

I think your original option to stitch the images together (AgriSoft) & anything similar should work with images captured via any control app as they will all have the x, y, z, tilt, pitch, etc. information required. On my list of things to do is capture via DD app then upload to the PH site to see how that goes.

 

[Toddvg]

I have been playing around with photogrammetry for a few months now. Trying Meshroom (free program) for my sticking and DJI go for my photo taking. Then I moved to Drone Deploy and now back to Meshroom using DJI Pilot app.

It is strictly a hoppy for me, with the Biggest challenge being able to share my Models once completed. free share websites limit the size of the file from 50MB-100MB. They are really for CADD type models, or people that create animated type characters. If you area doing a model of a building that has any good quality it is near impossible to have a model under 100MB.

I have found that the most difficult step in the photogrammetry process, is photo settings. It is not about the number of photos, but more about the actual quality of the photo.

 

[bushie]

I use Drone Harmony for photogrammetry Does a good job.

 

[JoostGT3]

In addition, I have used the POI mode of the mavic with some success; let the drone fly three circles around your subject and modify the altitude and circle diameter after each circle. Then use software to split the movie into separate pictures. This will result into a "dome" of photos, which should give you sufficient material to work with in case of a building or so.

 

[Toddvg]

Interesting, so you take a video then make that into photos. Then you upload those into what program?

Few questions:

If you were going to create a model of maybe a Ranch style home, what altitude would your 3 circles be & what distance from the center of the home would you be?

Do you have the camera set on automatic?

How many photos are you creating per circle to get the best results?

What program are you using to convert video to Jpg?

What program are you using for creating your model?

What program are you using for sharing your models?

 

[Toddvg]

I use Drone Harmony for photogrammetry Does a good job.

What is the cost for Drone Harmony??