When you're on the GeoNadir platform, you have the option to view drone mapping data as three different types of processed products.
Orthomosaic - This is the image that we create by 'stitching together' all of the individual original overlapping drone images.
Digital surface model (DSM) - This is a visualisation of the surface of the different features in the area that has been captured. Imagine throwing a sheet over the surface of the earth and viewing all the lumps and bumps from above. That's the DSM. It includes trees and buildings in those bumps.
Digital terrain model (DTM) - This is a visualisation of the ground. It attempts to remove the extra lumps and bumps from the trees and buildings to show what the terrain itself looks like.
You can switch between these three visualisations in any map view as below.
Note that not all datasets have been captured with the appropriate parameters to derive these three products.
Further, some older datasets may have orthomosaics, but not a DSM or DTM. We will populate these over time. Feel free to contact us if there is a particular dataset that you are interested in that doesn't have the product you need.
For more information about DSMs and DTMs, here's our blog about 3D drone models.