A Standard Operating Procedure
What are you monitoring for and what do you want to know or document?
The methods for reconnaissance (1) and mapping (2) are different.
1) Recon uses the video camera for filming the habitat as you fly around the study area.
2) Mapping uses either a still camera or a lidar unit and requires software that preprograms the flight and takes command of the drone to fly a grid pattern. Still images are taken straight down in an overlapping arrangement to produce a mosaic ortho photograph and a 3D topographic model of the ground.
Standard Operating Procedures are currently being worked on by the folks at UMass. A report was issued by DEP in June 2024 that lays out some parameters for consideration when documenting saltmarsh restoration projects.
The upshot in all 25 pages of DEP’s hither-to-fors is the drone pilot may document the restoration process. Before you begin any flights, find a local surveyed vertical benchmark (BM) with a known elevation in NGVD88 (Ground Control page is under construction). Set up ground control points with targets within your restoration area and GPS these points for state plane coordinates and an elevation, beginning with and ending with the known BM. Use a survey grade GPS with an accuracy of plus or minus 1 centimeter horizontally and 3 cm vertically. Now you are ready to set up a flight.
Using your drone controlling software, set up a project including all of the area under construction. For most flights an altitude of 200 feet above the ground is good and an overlap of 80% works well for 3D models and orthophotographs. Before flying, consider tide height, sun height and angle, restricted flight zones and wind. Flights near noon can acquire sun reflections in the water and confound post-processing software. Document your project parameters such as drone used, time of flight, duration of flight , number of photos, people present, weather, etc. Then hit the launch button. Unless you have a “Beyond Line of Sight” waiver, keep the drone in sight at all times.
Products from your flights should include an orthophoto and a digital elevation model.
During active restoration, a flight should be conducted once every 2 weeks.
OK