The images captured by the drones and processed by 3Dsurvey software generate the product that the surveying professional needs for their project. To do a correct job, the professional drone pilot must mark a perfect flight path and take a large number of consecutive images. When the drone has covered the entire extension of land to measure, the photographs go to a software that overlaps them to assemble a three-dimensional image.
For the house in Tuscon, AZ, US which was going up for sale the information about where water was draining on the property was requested.
The project was done by Surveyors Source LLC from Arizona. They flown with a DJI Mavic 2 PRO and took approximately 400 photos with a combination of circular flights around the hill and some nadir shots to create a good orthophoto.
For autonomies flight professional drone pilot software – 3Dsurvey Pilot (flight planning software) was used. The flight took less than 10 minutes and the result were high overlap images – more than 70% in side and front overlap. After the field work was finished the processing step continued in office. For this project the most important result was accurate Digital Elevation Model (DEM) which tells us information about where water was draining on the property. DEM contour lines helped us to define the terrain characteristics and orthophoto with the combination with realistic full 3D model helped us to design additional changes.
To work efficiently the following integrated functions in 3Dsurvey software were used:
Automatic classification – to extract terrain points
Point cloud reduction – since the computer used for this processing was not the strongest one and becase there was no need to work with 63 millions of points, they were reduced to 10% with just one click
Automatic CAD points extraction – tools to extract the lowest point based on predefine radius were used to see the height on specific areas
Contour line creation