Who can use this feature
Dataset owners within a Professional or Pro + workspace.
Selection requirements for tool to work
Drone dataset
This feature lets you apply a constant vertical adjustment to your DSM and DTM across an entire drone mapping dataset. It’s a simple way to standardise elevation values to match known reference points, correct small systematic offsets, or align outputs between different surveys. This is especially useful for multi-temporal analysis, where consistent height baselines are essential for accurately measuring change over time (e.g. erosion, vegetation growth, or site progression) without introducing errors from differing elevation starting points.
Note that this action cannot be undone, but you can offset it by applying an equal adjustment in the opposite direction.
To perform the DEM adjustment in GeoNadir:
Hover over your dataset in the table of contents to bring up the 'kebab' options menu
Click the kebab
Go to Enhancements > Adjust DEMs (or use the toolbox from the top menu bar to open those options)
Enter the adjustment value (negative numbers will be subtracted from the DSM and DTM; positive numbers will be added to it)
Click to run the adjustment
The time to perform this adjustment will depend on the size of your dataset, but it's likely to be a few minutes. While this is running, you won't be able to do any analysis on that dataset.
This is a permanent change and will also apply to all instances of that dataset in other projects, as well as any future downloads of your DSM/DTM.
Determining the adjustment amount
Not sure of the adjustment value? Try these options:
Use the inspect tool to view the elevation in your DSM/DTM at a known point. Find the difference between this value and the known value.
Select one dataset to be your reference. Use the inspect tool to evaluate the DSM/DTM values of the reference dataset, and the dataset to be modified. Adjust for the difference. Make sure that the location is the same in both datasets and that the elevation would not have changed between dates (e.g. pick a road intersection rather than a sandy beach).
If the values vary somewhat between you reference and data to be adjusted, you might like to choose a number of points and calculate the average.
You can also calculate the average values within a polygon area for better representation. Use the calculate statistics tool to obtain summary values.
Verifying the adjustment
Use the inspect tool to check the new DSM/DTM values in your dataset
Use the terrain profile tool and check that your values are as expected vertical or y-axis
Open the dataset details to confirm the value you used for the adjustment (default will be 0 for a non-adjusted dataset)