I just completed the next phase of my work on possible elevation map improvements for DroneDeploy. In this post, I summarize some of my prior work and then highlight some conformal elevation map possibilities.
Here is the DroneDeploy Elevation Map of a 17 acres site captured with a DJI Phantom 4 Pro drone:
To illustrate other elevation map possibilities, the 3D model for this mission was exported to Rhino which created a 3D mesh of the model. Then the mesh elements were colored according to their elevation using a 70-color palette with a twice-extended color range compare to the DroneDeploy palette (1) on the low-elevation side, a magenta-to-dark_magenta gradient was added while (2) on the high-elevation side, a red-to-black-to-white gradient was added. Also less aggressive hillside shading was used in order to more clearly show the informative elevation colors and to brighten the map. To enhance color-to-elevation translation, a map-height color-key was added to the left. Click on the map to see details.
Since the elevation coloring was done on a 3D model, a perspective view of the elevation map is now possible as show below. This view provides a much clearer understanding of the overall topography of the site. In terms of coloring, the perspective view of the 3D map provides more area. Compared to a 2D view, this enables the use of a larger color palette to match the color spatial-resolution of the eye. As a consequence, the information content of the map is increased.
This site has available a LiDAR bare-earth map:
If DroneDeploy adds the capability to import LiDAR site maps, then conformal elevation maps become possible. In a conformal map, the colors show the height of objects above ground level over the entire site. Such a map can be made in two ways:
(1) The first way is by coloring the 3D model according to the elevation difference of the site and the LiDAR map. This results in a map with the same topography as the normal 3D elevation map but with colors that show the conformal elevation. The 3D conformal elevation map for this site created in this way is shown below in both top and perspective views. The conformal elevation map provides a much more informative view of the 1000+ trees on this site. The location of the tallest trees on the site can now be clearly seen. Click on the map to see details.
(2) The second way to create a conformal elevation map is by reducing the height of each point in the 3D model by its LiDAR map elevation and then coloring this conformal 3D model. The colors then show the conformal elevation. The perspective view of the conformal 3D model for this site is shown below:
This view of the site removes all of the topographical distractions. Thus it provides a clearer view of the site’s tree inventory. It also gives a much more direct feeling of the 2 million pound biomass on this site. Finally, it enables additional processing possibilities that I am exploring.
In summary, I am suggesting the following 7 improvements to the DroneDeploy elevation map:
- An extended color pallet to increase the color resolution of elevation maps so they better match the color spatial resolution of the eye. This is particularly important for 3D maps with their much larger coloring area.
- A larger, map-height color-key for easier color-to-elevation translation @
- A 3D elevation map with perspective viewing. The large vertical area in a 3D maps increases the number of colors that can be used without exceeding the color resolution of the eye. This significantly increases the information content of the map.
- Improved hillside shading for clearer viewing of the informative elevation colors and a brighter map
- Import of a LiDAR bare-earth site map
- 3D elevation map with conformal elevation colors
- 3D conformal model with conformal elevation colors
These enhancements, implemented within DroneDeploy, should provide even better looking maps than I have shown here. This is because the exported 3D model does not contain as many details as in the 3D model used to create the DroneDeploy 2D elevation map.
@ I have more enhancement suggestions for the color key. They were not include here in order to provide more focus on the elevation map itself.
Thank you for your consideration of these enhancements.