How Accurate and Precise is Your Drone Map? Can You Prove It?
Many industries have started using drones for mapping related uses—everything from volumetric measurements, topographic maps, change over time, and other applications. The number of people offering these services has grown just as dramatically.
Whether you have an in-house crew that handles all mapping related projects or hire a third-party to complete the work, do you know if the final product is accurate or just a pretty picture? Are they recreational grade, mapping grade, or survey grade quality?
Before you task your in-house group or hire an outside provider to map your site, you need to determine how accurate of a map you need. Do you really need survey quality? Generally speaking, if you are using maps for measurements such as distances, areas, or volumes, you likely need survey grade quality, which is typically much more exact and costly versus recreational grade.
Not all maps are created equal. Many firms offer low-cost, attractive maps, but the measurements derived from those maps may not be valid. It’s best to ask some straightforward questions first.
A few questions to consider: Is the mapping crew using ground control points and check points? Do they understand accuracy is relative to the ground sampling distance (GSD) value? What are they using to measure these points? Is the equipment, in ground or air, limiting the accuracy and/or precision they can achieve? What photogrammetric software are they using to stitch the images and rectify the maps? How much control do they have over the processing of the data?
A mapping project can be broken down into two major phases: 1) field data collection, and 2) data processing and analysis. We have found field data collection is, while important, easier to train personnel to attain survey grade products. Data processing and analysis generally requires more survey and photogrammetry knowledge to produce quality deliverables.
Westward Environmental Inc. drone experts can audit your existing program, provide turn-key outsourcing solutions, assist in the field and/or conduct data processing/analysis, and train your staff with the most advanced technology and know-how.
Quick note: some states define surveying to include drone generated maps or measurements. Check your state’s regulations as to what they define as surveying.