Residential house
Objective and outcome of the task
These missions were to further refine mission planning and aircraft & camera settings. They were also to fly over a residential house in an urban or suburban environment to develop operational capability and safety also applicable to urban and suburban environments.
The mapping missions were flown as planned and without any technical or operational issues, giving confidence for performing similar missions in urban environments. The 2D maps presented below show the areas where the mission area has caused the absence of photos to sufficiently capture the entirety of the subject house. All three missions were flown using the smart oblique mission type and captured very similar numbers of photos over similar elapsed flying times, showing that trying to reduce the area overflown too much and not gather a complete data set is not worth the risk.
The zoomed 2D map for the large mission area photos clearly show a substantial amount of detail regarding the condition and potential damage to a roof. These missions were flown at over 35m (to clear the trees close to the property boundary) and at a relatively high airspeed (to minimise mission elapsed time). This roof has some staining around the vent pipe, moss growth, cracking in the chimney pot cement and some vegetation in flashing gulleys & gutters, but it is otherwise generally in good condition after 20 years' service.
The mission profile screenshots show that this mission type extends substantially beyond the area of interest, and selection of this mission type for mapping of a more urban subject should be carefully considered with respect to uninvolved people, tall trees, other buildings, roads, privacy, etc. Because of the proximity of buildings and trees it was also a planning and operational challenge to always keep the aircraft within sight.
How the data was gathered and processed
Three missions were flown over the residential house to test the effect of proximity of the mission area to the boundary walls of the subject on the time & distance flown, number of photos, and the quality of photographs, 2D map and 3D model.
Large area - mission area extending beyond building boundary
Reduced area - mission area closer to building boundary
Building boundary - mission area at building boundary
The missions all took approx. 2 minutes elapsed flying time and 38, 40 & 35 photos (respectively) were captured during the three passes over the site. The photos were processed using the DJI Terra app, all taking between 5 & 6 (respectively) minutes of processing time on a Windows 11 PC with a 32-core Intel Core i9-14900 processor, 64GB of RAM and an Asus Nvidia 4060 GPU.
2D Map
The 2D map was output by DJI Terra app as a GeoTIFF file. The GeoTIFF was used to create PDF and JPG files of the 2D ortho-mosaic and uploaded into Google Earth Pro to create a geo-referenced tile overlay on the Google Earth globe. This can help visualise the subject in its surroundings.
The GeoTIFF is also a very detailed ortho-mosaic image and can be examined to understand the condition of the subject, e.g. damage to woodwork, masonry, brickwork, roof tiles/panels, etc.
Large area - mission area extending beyond building boundary
Reduced area - mission area closer to building boundary
Building boundary - mission area at building boundary
3D model & animation
The 3D model can be examined to enable measurements of distance, area, volume and slope to be taken; these have been verified to be within millimetres of the actual values.
The 3D model was shared as a link from the DJI Modify app, to be viewed in a web browser. Animation of the model in the viewer was screen recorded. (The viewer can navigate around the model using the mouse. The 3D model can also be output to a number of formats compatible with various CAD, GIS, etc. apps.)
If you are interested in any of our services click here to email us
Airborne Insights is a trading name of Logistics Partners Consultancy Limited
