Yang, B.; Hawthorne, T.L.; Hessing-Lewis, M.; Duffy, E.J.; Reshitnyk, L.Y.; Feinman, M.; Searson, H. Developing an Introductory UAV/Drone Mapping Training Program for Seagrass Monitoring and Research. Drones 2020, 4, 70.DOI:10.3390/drones4040070
Unoccupied Aerial Vehicles (UAV), also known as small Unmanned Aerial Systems (sUASs), Unmanned Aerial Systems (UAS) or drones, with their high spatial resolution, temporal flexibility, and ability to repeat photogrammetry, afford advancements in other remote sensing approaches for coastal mapping, habitat monitoring, and environmental management. This open-access drone mapping training course is designed to use drones to collect remote sensing data for coastal mapping and seagrass conservation. We create this training course for research partners and broader communities to learn how to fly drones, and perform data processing in Geographical Information Science (GIS) method. This training course contains topics of flying drones, Preflight & Planning, FAA part 107 examination, Drone2map user guide, and GIS based drone image analyses.
Basic knowledge of Drone, setup, and maintenance.
Learn how to fly drones, manual manipulation and auto-pilot.
Operate the UAV efficiently, safely, ethically and consistent with FAA regulations.
Learn FAA part 107 exam, e.g., airspace regulations, sectional charts, and etc.
Safety guidelines when flying drones.
Learn to use DJI GS Pro for auto-pilot flying and collecting field data.
Collecting field data and Ground Control Points (GCPs).
Use Esri Drone2Map to stitch and geo-referencing the drone images.
Data management and cloud storage of drone imagery
Basic GIS analysis on drone imagery, digitizing, multi-spectral band math, vegetation index, and image classification.
The training program is divided into 5 training sections and one post-training self-study guide to prepare participants for the FAA Part 107 examination. This examination is necessary for commercial-based drone operators to conduct flights in the United States.
1. Drone Basics
The first training module includes a tutorial to introduce basic manipulation, assembly, setup software, and calibration of the quadcopter drone. The DJI Phantom 4 Pro were used as an example. The training contents includes a lecture-based review of the drone, its basic flight manipulation, rules and regulations for drone flights. Through the lecture and tutorial, safe drone assembly techniques were reviewed as well as safety requirements. We covered pre-flight planning and in-flight precautions, including maintaining UAV within visual line of sight of the remote pilot.
Read the Phantom 4 manual to learn basic manipulation, assembly, setup software, and calibration of the quadcopter drone.
Review the drone, its basic flight manipulation, rules and regulations for drone flights.
Following the overview of drone basics, there is a 1.5-hour manual flying session. Through this interactive exercise, participants gained experience in basic drone operations.
Remote pilot checks for safety equipment including gloves, eye protection, safety vests, radio, and life jackets if taking off from a boat
The flight is not permitted directly over non-participating people.
Because coastal mapping with drones often includes taking off and landing on a boat, hand catching of the drone on a boat needs to be practiced for both takeoff and landing.
Focus on maintaining visibility and line of sight with the drone and avoiding hazards.
Open training course for drone mapping: (3/5) Calibrate the drone and setup the software
Air Space Regulation
All drones are required to be registered with the FAA if they weigh more than 0.55 lbs (250 grams) and less than 55 lbs (25 kg).
Maintain UAV within visual line of sight of the remote pilot. a) standard flight altitude (< 400 feet above ground level (AGL); b) minimum distance from clouds (> 500 feet below the cloud and 2,000 feet horizontally from the cloud); and c) maintaining a safe distance from bystanders.
The minimum distance of the UAS from clouds must be no less than 500 feet below the cloud and 2,000 feet horizontally from the cloud.
U.S. Part 107 (FAA sUAS Part 107) specifies regulations to fly a UAV in the National Airspace System (NAS). Jurisdictional differences across study sites affected some flight restrictions under FAA regulations. For sites within controlled airspace, Low Altitude Authorization and Notification Capability (LAANC) and Certificates of Authorization (COAs) needed to be considered and planned for well in advance of drone operations.
Note: There are similar regulations in Canada. All drones that weigh between 250 g and 25 kg must be registered with Transport Canada. FAA certification (U.S.) is not applicable in Canada, and drone pilots must follow the rules in the Canadian Aviation Regulations (CARs) Part IX—Remotely Piloted Aircraft Systems.
Autonomous mapping provides an advantage over manual flight operations by ensuring that data collection is efficient and replicable at each site. In this module we learn how to use autonomous functions to capture hundreds of images that were pre-programmed to be evenly distributed with nadir view over the mapping area.
Read the [CSGIS_Preflight_Planning_Document] (/Documents/CSGIS_Preflight_Planning_Document.pdf) in the course material, learn to use DJI GS Pro app for auto-pilot and safety guidelines.
Learn how to plan and create autonomous flights with different mapping parameters.
We recommend UAV flight path set to be parallel with the long side of the mapping area in order to minimize the UAV turning points and maximize battery efficiency.
Rain, wind, and fog all frequently occur in coastal areas and influence drone flights. To address that, flights need to be conducted with wind speeds less than 10m/s, no heavy rain and no fog. FAA Part 107 regulations state that the UAV should not be flown in fog or other situations where the operator loses line of sight.
Open training course for drone mapping: (4/5) Create drone mapping task using DJI GS Pro
Mapping planning & settings
Participants learned how to plan and create a new flight area using autonomous flights with different mapping parameters. Considerations for autonomous parameters included:
Tradeoffs between spatial coverage and spatial resolution (e.g., if drones fly at a higher elevation, the image coverage is larger, but the spatial resolution is coarser and vice versa);
Appropriate settings of the camera model for a proper shooting angle to minimize sun glint;
How flight direction and capture mode vary depending on the shape of the site and the wind directions;
How front/side overlap ratio is related to flying time and the number of batteries needed.
Open training course for drone mapping: (5/5) Unlock fly zone and Using DJI GS Pro for autonomous mapping
The general steps reviewed in this course included: image stitching, geo-referencing, derivation of orthomosaics and elevation models and image correction. Also, we will review the importance of visually inspecting all drone images to rule out low-quality images (e.g., blurry or oblique) and minimize measurement error in the final data products. This module will also cover the use of Esri Drone2Map software to stitch together hundreds of separate images collected by drones in the field and geo-register them into orthomosaics.
Findable, Accessible, Interoperable and Reusable (FAIR) science data principles. (Wilkinson et al., 2016),
Note: Drone2Map software package could be downloaded from the course material resources folder. Sample data are provided in the course folder.
One of the biggest challenges of coastal drone mapping is that a relatively homogeneous water surface leads to difficulties in registering images because the image mosaic algorithm usually needs some target on the image as a matching point to stitch together images with overlaying parts.
For points on land, we used obvious objects, such as red buckets that could be easily identified in the drone image. For image referencing over the water, we used light-colored buoys with anchors fixed on the water surface to serve as the Ground Control Point (GCP). It is recommended to collect 10 points at each monitoring site. On land, use colorful objects, such as red buckets, that could be easily identified in the drone image. Over water, use light-colored buoys with anchors fixed on the water. When collecting GCP points, we recommended starting the GPS and wait until there were more than 12 satellites available for calculating the position. For each GCP location, we encourage to wait at least 90 seconds until the GPS signal became stable. Usually, GPS accuracy can reach 30-50 cm under cloudless weather conditions. For each GCP location, collecte 20 repeated measurements and use the average value as the input coordinates for geo-referencing.
GIS analysis includes: geodatabase management, digitizing raster imagery, pixel/object based classification methods, band math, and calculations of vegetation indexes (e.g., Green Leaf Index and NDVI). The canopy information, such as Leaf Area Index (LAI) can be derived from drone imagery as well (Roth et al 2018).
Note: ArcGIS and Drone2Map software packages could be downloaded from Esri.
UAV/drone high-resolution 3D fly-through video for Bodega Marine Laboratory (BML)
Furthermore, drone mapping can generate additional elevation data products, such as Digital TerrainModels (DTM) and Digital Surface Models (DSM). Such products are useful for topography analysis and 3D visualization. Above video shows the high-resolution orthomosaic imagery combined with the high-resolution Digital Elevation Model can be further processed to a 3D visualization.
10-hour self-paced study guide to assist partners with the Federal Aviation Administration (FAA) Part 107 examination. In order to fly drones for research purposes under the FAA’s Small UAS Rule (Part 107) in the U.S., one must obtain a Remote Pilot Certificate from the FAA. This certificate demonstrates that the remote pilot understands the regulations, operating requirements, and procedures for safely flying drones.
Above training document reviewed content from the course modules as well as additional material necessary to prepare for the drone examination, including airspace concepts, weather sources, radio communications, sectional charts, and drone physics. It also includes additional online resources and sample questions for the examination.
Before Flight Check-list
Registered the drone with FAA, checked the airmap or B4Ufly that the mapping area is approved by FAA.
Install “DJI Go 4” and “DJI GS Pro”. Note GS pro only available on iPad (no iphone version).
Charge both controller and drone batteries. Each battery takes about 1 hour and 20 minutes to charge to full, the controller needs about 3 hours. There are two charging ports on the original charger, one for the controller and one for battery.
There is a 32gb sd card coming with the drone. Make sure to clear it before going to the field. If using a computer to format, use the fat32.
Take a test fly to confirm everything is good and the drone can take off. If the drone is good to be taken off, that will save lots of the time when doing the mapping in the field.
Check everything is good using DJI GO 4 before use GS pro, then go to GS Pro and click to fly. The take-off location is better to be flat, dry and close to the mapping area as much as possible to save the battery.
When the drone fly to the area and start mapping, make sure turn on the sound of the ipad and hear the shutter sounds every 2-3s. Sometimes if accidentally clicked video shooting at some point before the mapping, the drone will pretend to do the mapping, but keep shooting video without the notice.