How I Mapped Hundreds of Acres with DroneDeploy

2D map generated from hundreds of photos by DroneDeploy

In September 2016 I used DroneDeploy to map 200 acres of undeveloped land using a DJI Phantom 4. DroneDeploy is a cloud service, mobile app, and web app for creating ground maps of large areas. It’s targeted towards industries such as agriculture and construction which can utilize camera drones to inspect crops, construction progress, and perform many other functions. Below are details of my experience using it along with tips about how to get great results mapping large areas with DroneDeploy.

Camera drones can save a tremendous amount of time and money over using helicopters or traditional manual inspection methods. Think about hard to reach or hazardous environments that would create safety or liability concerns for people to inspect. DroneDeploy’s fundamental set of features enable you to:

  1. Create flight plans by defining the area to fly on a Google Map and setting the flight altitude.
  2. Automatically fly your DJI drone to take a set of photos covering the target area.
  3. Upload and stitch together up to 3,000 photos to create 2D, 3D, elevation, and plant health maps. If you’re not using a DJI drone you can upload photos that you’ve taken when flying manually or through another app.

I was excited to use software that could both automatically fly my new Phantom 4 as well as stitch together hundreds of photos taken by the drone. So I tried DroneDeploy on 200 acres of undeveloped land which is currently being used for oil drilling and cattle grazing. These two uses require a fair amount of land which can take a long time to inspect from the ground. Oil wells must be spaced far apart from each other to be effective and away from the property border so as not to tap into neighbors’ resources. Also, you can’t put too many cattle on a piece of land or else they’ll overgraze and prevent the grass from regrowing.

Previously I tested DroneDeploy over a 10-acre park which only required a three-minute flight. Since this was a much larger piece of land, I had planned on spending a few hours of one day to finish this project. However, I ended up spending many hours over three days to complete a flight over the entire property and get all the images I needed. Flying over a large area meant interrupting the flight twice to change the battery, which increased the difficulty of using DroneDeploy.

Preflight

This is where the bulk of the work using DroneDeploy is done. You can use either the mobile app or website to create a flight plan. It’s helpful to scout out the target area in person beforehand to get an idea about obstacles such as construction cranes or trees which need to be avoided. Even though drones like the Phantom 4 have obstacle avoidance, you don’t want your mapping flight to fail due to obstacles. I wasn’t able to visit this location before attempting my flight so I planned the best I could using existing Google Maps satellite images.

Create a flight plan from the mobile app

Creating a flight plan is as simple as drawing a bounding box on a Google Map and setting other parameters such as altitude. I made the box larger than the area I wanted to map to make sure the edges were included and set the altitude to 302 feet. At that altitude the flight would take under 30 minutes. Since that’s only slightly longer than the life of one Phantom 4 battery I thought this would be an easy flight. I also read up on DroneDeploy’s procedures for interrupting and resuming a flight to change batteries.

Day 1

I took off at the highest point of the property and flew the first 58 of 226 acres until the battery reached 34%. Then I hit the home button to disrupt DroneDeploy’s automated flight and return home so I could change the battery. After powering the drone back up I hit Continue in the DroneDeploy app. However, it restarted the flight from the first waypoint and never gave me an option to continue the previous flight. I didn’t have enough batteries to try it all again, so for the entire day I flew less than one third of my target area. The default starting waypoint was furthest away from me, so it cost a lot of extra battery life to fly there and start from the beginning instead of starting closer to me.

After this experience I learned how to manually change the starting waypoint to where the last one left off. By changing the flight direction, I could also set the starting waypoint to be the one closest to me.

Continuing a flight from an intermediate waypoint after changing batteries

Day 2

For the second day of flying I decided to takeoff near the entrance to the property to avoid having to drive up the dirt hill again to the previous flying location. However, this caused a lot of problems with the controller disconnecting from the drone, which caused the drone to stop taking photos. The disconnections happened immediately after taking off and I burned through my three batteries by retrying the flight a few times. As a result, I didn’t complete much of the flight plan except for a small portion of the north end of the property.

Afterward I Googled this problem and found the issue. When the Phantom 4 loses signal from its controller, it stops taking photos at the two second interval preset by the DroneDeploy app. The drone is safe and continues to follow its preloaded waypoints but this problem interrupts the photos taken during the flight. It was surprising that the controller needs a constant connection for the drone to keep taking photos. Therefore, I realized that future flights would have to be made from the highest point with a clear line of sight to the entire property. Later that night I drove to Best Buy to buy a fourth battery to allow me to try two full flights over the entire property and be prepared for additional problems.

Day 3

On the third day I was determined to learn from lessons of the past two days and complete an entire flight. Equipped with four fully charged batteries, I went back up to the highest point of of the property to reduce the chance of interference interrupting the drone’s photo taking process. This time I was able to complete three flights to cover the entire property, taking 785 photos! At the highest point of the property there was no controller disconnection. Also I kept track of how many waypoints were completed to ensure that the flights could be properly resumed after switching batteries. All flights went smoothly and I was very happy to finally complete a flight over the entire property.

Eager to check the results of the flights I immediately downloaded all of the photos to my laptop. It was quickly apparent that the exposure and white balance settings were very different across all three flights. Since the terrain was the same across the entire property they should have looked similar. I had encountered this problem during previous tests and DroneDeploy’s support team told me that this is a problem specifically with their software and the Phantom 4’s camera. With limited battery life left, I flew the third flight again to capture a new set of photos which ended up closely matching photos from the second flight.

Automatic camera settings produced very different results across flights

With the remaining battery life, I flew a different flight plan at an altitude of 100 feet to capture more detail over some oil & saltwater tanks. Even though I was less than 150 feet away from the drone it still encountered problems with the controller disconnecting from the drone and ending the photo taking process prematurely. I was a bit confused as to why this was happening so close to the drone until I realized that power lines or pumping equipment nearby were generating electromagnetic field (EMF) interference which interrupted the controller’s signal.

Post-flight

Using Adobe Lightroom, I manually adjusted the photos from the second and third flights to match the properly exposed photos from the first flight. Then I uploaded all of the photos to dronedeploy.com and waited for the cloud service to work its magic. Within a couple hours I received an email telling me that the processing was done. The 2D, elevation, and plant health maps along with the 3D model were ready for viewing.

2D map, elevation, plant health, and 3D model views generated by DroneDeploy

When I first saw the 2D map that was generated I thought it looked similar to a Google Maps satellite view. The benefit of using DroneDeploy is that you can fly and generate these maps as often as you’d like, and you can generate really high resolution maps by flying at a low altitude. The 3D model, elevation, and plant health maps are also tremendously useful for various industries. The DroneDeploy web interface provides many tools for interacting with the views such as taking area measurements, rotating the 3D model, and adjusting color bands for the elevation & plant health views.

Measuring and annotating an object on the 2D map

Tips for Great Results

Based on this experience mapping a large property with DroneDeploy I have come up with some tips to follow in the future.

Manual Camera Settings

Use DJI Go beforehand to manually fly over your target area, take photos, and adjust the camera settings. For DJI drones make sure to choose 4:3, JPG, and the shutter speed you want. Note that most of the cameras on drones have a fixed aperture so you don’t have the option to adjust that. Leave the drone on manual camera settings before quitting DJI Go and launching the DroneDeploy app.

Extra Batteries

Bring plenty of batteries for you to retry your flight in case something goes wrong. Battery life shouldn’t be an issue for most construction sites that take only minutes to fly over. However, for large farmland that takes over 20 minutes to fly over, you’ll probably need to use multiple batteries per flight. If there’s a problem and you need to repeat the flight, you’ll want to bring enough power with you. I originally brought three batteries but ended up buying a fourth while traveling which allowed me to get more photos. Having a car charger handy is also a good idea, although your car engine may have to be running for the charger to work.

Takeoff Location

Stand with the controller in a location that is at the highest point of the land you’re mapping and has a clear line of site to the drone for all segments of the flight. Watch out for power lines or other sources of electromagnetic field (EMF) interference which could interrupt the signal between the controller and drone. Note that the waypoints are preloaded into the drone so that the actual flight won’t be interrupted if signal is lost, just the photo taking.

Starting Point & Flight Direction

Think about where the starting waypoint on the flight plan should be, which is different from where your drone physically takes off. By default, DroneDeploy chooses the southwest corner of the flight plan. However, depending on where the takeoff point is and how much ground your flight map covers, a good amount of battery life may be spent flying to the starting point before the drone even starts to take photos. Therefore, you can adjust the flight direction which also rotates the starting point around the center of the flight plan and bring it close to the takeoff point. This will enable the drone to take photos right away so you can encounter potential problems quicker. On the other hand, you may want the starting point to be furthest away from the takeoff point so that if there are any problems with range they will show up immediately.

Choose Your Time of Day to Fly

The best results can be obtained when the sun is high overhead and casts the least amount of shadows, typically from 10 AM to 2 PM. However, this can very based on location and time of year so check it out ahead of time. In the plant health map that my flight generated there were too many shadows and they mistakenly showed up as unhealthy areas.

Closely Watch Flight Progress

The DroneDeploy app shows a lot of information while executing the flight plan. Pay close attention to how many photos it’s taken and ensure the number keeps increasing. Also, keep track of the latest waypoint which was passed so that you can easily resume later after flight interruptions such as changing batteries or losing the connection from the controller.

Install Updates Before Flying

Check for drone firmware and DroneDeploy app updates in an area with a Wi-Fi or cellular network signal the same day you plan to fly. I do this either from home or my hotel room if I’m traveling. Turning on the drone and taking a photo is a great way to check that everything is updated and working before trekking out to the flying site.

Summary

DroneDeploy is a great tool which provides features which would otherwise be difficult to do on your own with multiple other tools. After following the tips I’ve detailed here and devising your own best practices you can create large maps while still having fun!

Drones love sunsets
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