Is it possible to use satellite stereo images and RPC files to generate DSM in ODM or OpenDroneMap…
With enough overlap, it is theoretically possible, though one would need to be careful interpreting the output as a DEM.
Sorry… Do you refer output will be DEM., but I need output as DSM(including land features such as buildings, trees etc)
DEM I use as a general term that includes DSM and DTM. In this case, yes, DSM would be the output. See e.g. Minimum number of overlapping images for point-cloud generation
I will see. Thank you very much.
I am trying to create EDM (DTM/DSM) from a pair of Pleiades satellite images with over 90% overlap in both directions. Have tweaked the following parameters but I still get this error
[ERROR] The program could not process this dataset using the current settings. Check that the images have enough overlap, that there are enough recognizable features and that the images are in focus. You could also try to increase the --min-num-features parameter.The program will now exit.
Different parameters tested in WebODM:
depthmap_min_consistent_views: 2 (Default was 3)
min_num_features: 1000 & 10,000 & 30,000 (Default was 8000)
opensfm_depthmap_method: BRUTE_FORCE & PATCH_MAP
Here’s the link to download the original dataset including two satellite images and dependencies if anyone wants to try : https://drive.google.com/drive/folders/1fTdCxtXwi1mWLyJKuzO7btW_mLQBg86b?usp=sharing
Any suggestions on how to tweak parameters to be able to create DTM/DSM from a pair of satellite imagery?
I’m thinking maybe the problem is actually in my images. I guess we should have used stereoscopic satellite images instead of finalised georefed TIFF. Not sure …
Very interesting use case. Two things:
- Raw images are recommended rather than georeferenced tiffs. Georeferenced tifs have already had (most) elevation impacts removed
- You will need more images. 5 is generally considered the minimum, though 16-32 is a more practical minimum range. Since the tool isn’t purpose built for stereo pairs but for mult-stereo views, it starts from an assumption of having much more than two views. This means it works really well for multi-stereo view use cases, but poorly for fewer than ~20 images, and not at all for fewer than 5.
Thanks Stephen. Will try those too
Also found this service which is super expensive but cool: https://www.geoimage.com.au/DEMS/dems-overview
I was wondering if ODM is not entirely designed to process limited number of datasets such as satellite imagery, then would there be an easier way or perhaps some existing plugins to generate DEM (DTM/DSM) from just a few satellite images in QGIS?
I don’t know the other options at this point, but for sure OpenDroneMap isn’t designed for pushbroom systems, and only works with lots of image because it can approximate a camera model from them. More focused systems already have sensor/camera models built in based on known characteristics of the satellite borne sensors. This allows them to use ephemeris and those characteristics to constrain the model and produce elevation models from limited data.
In the FOSS arena, maybe something like Whitebox has some tools for this, although I haven’t tracked this area of development closely in recent years. In the closed source arena, PCI Geomatica and similar were designed for these kind of analyses, and i know Geomatica can be acquired a month at a time, which can control some for cost.