Rebuilding homes after a natural disaster like a wildfire can be tough. And while it’s hardest on the homeowner, it can be a difficult process for those who have to work on the project as well, including land surveyors. Thankfully, drone technology can help make this process smoother. This article goes over the more technical steps for how to use a drone for land surveying after a wildfire. To learn more about how this data can actually help the people involved, check out our previous blog post. All of the data shown below was collected by Aerotas customer WM Surveys in response to the devastating Thomas Fire in California.
1: Know what drone survey data you need
Good business is done by doing exactly what you need to do the first time. The single most common mistake in using drones to collect data is to gather gigabytes of data and then see what good can come out of this. Inevitably, this leads to enormous amounts of wasted time, and often doesn’t even result in good deliverables. An emergency isn’t when you want to be experimenting with what drones are capable of. You need to know this before going out into the field. In this case, WM Surveys flew the mission knowing that the goal was to gather planimetrics and topographic CAD data of the sites, as well as basic data about the house footprint, concrete and street edges, as well as any other walls or features on the site. It would be easy to spend hours doing analysis on the type of vegetation, quantity of debris, path of the fire, or analysis of the damage caused, but that would have taken an enormous amount of time and money. Given the thousands of homes that need to be surveyed, focusing only on exactly what you need will help keep costs low and turnaround time quick, and this is exactly the type of data that the Aerotas Mapping System is optimized for.
2: Be prepared with drone survey Standard Operating Procedures
There are dozens of minor tasks that need to be taken care of before any drone mission. In order to get the right data the first time, and to be safe, you need to take care of drone insurance, pilot training, mission planning, safety procedures, pilot licenses, and airspace authorizations just to name a few things. Checking airspace after a fire is especially important as there might be flight restrictions to allow emergency firefighting aircraft to fly, meaning that drones are strictly prohibited. These tasks are easy to forget when heading out in a rush. Professional standard operating procedures means knowing the data that you need, planning your mission beforehand, and preparing all of your equipment and paperwork so that field operations go smoothly. This will also ensure that you don’t have to make a site revisit. Having to make multiple visits to a site can erase the time savings you get from using a drone, but good SOPs will make sure you never have to make a second visit to a site.
3: Collect your drone survey data in the field
With proper planning and operations, time spent in the field is very minimal. In the case of the fire damaged property surveys, it amounts to gathering 5 ground control points set strategically throughout the site, and then pressing “go” on a roughly 10 minute autopilot mission that was planned in the office. Total time spent in the field was usually 30 minutes depending on whether or not the site required any other work on the ground. Most of the work happens both before and after field operations, not when you are out in the field. This means that an efficient surveyor can potentially survey 10 or more sites in a single day.
4: Process your drone survey data into final line-work
Data processing is where the largest amount of time can be wasted. In fact, it is not uncommon to lose all of the time advantages saved in the field with time spent struggling with data in the office. The steps to good data involve processing the data through photogrammetry software, running QA/QC on the results to make sure the model is accurate, and then drafting linework from the validated 3D model, before importing it into existing CAD software such as Civil3D or Carlson Surveyor. These steps are very difficult to master, which is why Aerotas has created the first service to offer professionally drafted CAD line work from drone data.WM Surveys only had to set ground control targets and fly the drone, then Aerotas produced complete CAD line work, not just point clouds or 3D models, within just a few days. By leveraging Aerotas’ expertise and economies of scale, WM Surveys received completed line work faster and more affordably than doing it by themselves. Faster, better data means more work and higher profit margins for the surveyor, all while helping the homeowners rebuild faster than they ever could before.
Start drone surveying today
Aerotas is proud to have developed a system that is helping people through such hard times. But it is companies like WM Surveys that is doing the real work, and we are proud to support them. To learn how your team can start drone surveying, visit aerotas.com/map