The Mission Planning Process
Highly accurate linework and photogrammetry deliverables are dependent on the way your mission is planned and executed. The following overlying mission planning key points should be considered for every mission.
Is your site appropriate for drone survey? How big is it? Is there ground cover? These and other questions need to be asked prior to deciding if the drone is appropriate for any given site.
Knowing what accuracy you need for your project will help you determine if the drone is appropriate for your project and help you select the correct altitude to fly at.
Your flight altitude is based on the accuracy you need, and also the topographic layout of the site at hand. Image resolution deteriorates as flight height goes up and thus accuracy becomes slightly less the higher we fly. On the other hand, flying higher saves a bunch of time! Determine what altitude fits your needs best.
Ground control points are the nails that keep our projects anchored and true to the real world. Quantity, quality, and distribution are all important factors to consider when setting ground control points.
For RTK drones, we recommend 5 checkpoints for every project as the drone already has the capability to geo-reference the photos it takes down to better than .1’ accuracy. Checkpoints are shot exactly the same as ground control points, however you only need a few of them and they are mainly used to VERIFY accuracy on a project, not actually create accuracy in the photogrammetry process.
In general, for most drone aerial survey, photo overlap should be set at 75/75, and flight patterns should be flown in a “lawnmower pattern” or a back and forth sweeping flight path over your entire site.
Create your flight paths
You will need to create flight paths in what ever drone mapping software you choose. We currently work mainly with;