Drone Surveying for Beginners – DJI Phantom 4
This right here is the dji phantom 4., its one of the most popular drones used in the mapping industry, and this drone has the ability to do aerial mapping and using the data that we can extract from the images. We can then survey that information now aerial mapping has been around for nearly 100 years. It was first used in world war, one when the allies took airplanes and mounted high resolution cameras in order to infiltrate their enemies territory. They would fly these planes with cameras, pointed in a nadir position at 90 degrees in order to do aerial mapping on their enemies land. This gave the allies a huge advantage because they knew exactly where all the features for their enemies lands were located. Using these aerial maps, now, of course, since the early 1900s, the technology has advanced tremendously and now we have drones, and these drones have high resolution cameras that we can use to fly and take imagery. Now, a traditional aerial mapping is still very relevant. We still send pilots on airplanes, carrying very expensive high resolution, cameras that are taking airborne imagery for us, the cost to operate a manned aircraft with a half. A million dollar camera is extremely expensive, not to mention the resources and the ability to find someone whos skilled enough to do it are very scarce, but now with drones, we have the ability to buy a drone as cheap as one thousand dollars and fly it in The air only a few hundred feet above the ground and capture extremely high resolution imagery and the images that are captured by this drone can be orthorectified and we can use it to do surveying in the office and today, im going to be showing you how you Can use a normal consumer grade drone in order to perform aerial mapping missions for surveying now, if youre interested in learning about surveying aerial mapping remote sensing, all this great technology be sure to subscribe to my youtube channel as ill be releasing several videos talking about this Great new advanced technology and how us surveyors can benefit from it and use it in a proper way.
Now there are a lot of important things that you have to account for when youre doing aerial mapping. However, as surveyors the most important the top priority, the one thing that we care most about is accuracy if the data looks pretty but its not accurate, then its just a pretty picture its, not a map. This is what gives aerial mapping a bad reputation. A lot of people dont fully understand how they can utilize aerial mapping by incorporating surveying practices in order to have accurate data. Now there are a lot of methods that you can use in order to achieve a higher accuracy map. The most common and fundamental method would be the use of ground control points as surveyors. We use total stations, levels and gnss receivers to collect data and to set high accuracy control points. So by incorporating these control points to aerial mapping were able to use something known as geo referencing to reference. These control points to our data sets these ground control points are set using targets, so were able to observe the position of the points up in the sky. The science of combining aerial images with ground control points to produce high accuracy, imagery is known as photogrammetry. Now today were going to be surveying. This cul de sac, using photogrammetry, well set several ground control points on this site and then georeference their coordinates to the imagery and generate an orthorectified map that we can then survey from heres a google earth image of the cul de sac.
So you have a better idea of what the parameters are that were going to survey now. Ground control points are also complemented with something known as checkpoints. Checkpoints are observed in the same way as ground control points are, however, they are not included in the solution. Checkpoints are not used to adjust the data that we capture from the drone. These points are only used to merely check our work and to make sure that the coordinates of the imagery lines up with the checkpoint, without actually adjusting to the point now for this project. Im going to be using a gnss receiver to set five ground control points and two checkpoints. Now, if you want to learn more about gnss receivers, ive made a playlist with several videos talking about it and make sure you check that out. If you want to learn more about these receivers now, when it comes to setting ground control points, you definitely want to spread them out as much as possible and put them on the exteriors of your project. Being that i only want to survey the right away of the cul de sac ill, probably set one point over here. Another point in the back a point on the opposite side in the back another point up front as well, and then one more ground control point in the center ill place. One checkpoint on this side, one checkpoint on that side, and that will be my control network for reference, heres, a google earth image showing where ill place the ground control points, as well as the checkpoints.
Now, before we start, i want to thank our sponsor for todays video e38 survey solutions if youre looking to incorporate aerial mapping into your work or if you have an existing aerial mapping company, you want to improve the accuracy e38 survey solutions can step in and help You improve your existing business or help you start incorporating aerial mapping. They are the premier us distributor for gnss receivers and drones across the united states, theyre based out of ohio and carry inlet, gnss receivers and dji drones. If you want to learn more about e38 survey, solutions check out the link in the description and make sure you let them know that rami sent you all right. Lets get started all right. Im going to place the first ground control point right here, all right! Im going to take my gnss receiver and im going to place the pole, the center of the target make sure this is plumb all right. I have my job loaded up on my gnss receiver and our output. Coordinate system is nad, 83 michigan south and our elevations will be navd 88 using ellipsoid 12b. How quick add a point – and i want my point number to be one description: gcp save my poll height is 6.56 feet, which is equivalent to 2 meters im going to be averaging shots for 10 seconds. I want to make sure my observation has a fixed solution. Okay measure, all right now we have coordinates of our first ground control.
Point all right well, go ahead and set the second control point here. Okay measuring point number two looks good Music, okay and good point number three. Okay, point number four: okay, good and point number five, which im going to be setting on the center of this island and measure. Awesome weve now set all of our ground control points. Now, im gon na set point number six, which is our first checkpoint. Okay and im gon na go and edit the description of point number six and change it to chk, which stands for check done, save measure, okay, good and well set the second checkpoint point number seven over here: okay – and we are now measuring the point. Okay, great were all set, and there we go. Weve now established our control network that were going to be using for our aerial mapping, project and now its finally time to set up the drone, make sure you guys check out surveyshirts.com. We have a bunch of different designed survey shirts for you to pick out from they come in a bunch of different colors and sizes. We do ship internationally, so make sure you check out surveyshirts.com and buy yourself a survey shirt now when it comes to drone mapping. Every drone is a little different. Some of them like this one have obstacle avoidance so that it doesnt crash into anything. Some of them have a fixed camera that you cant take off other drones like the matrice 300.
You can change out the sensors, so you can put on a camera a lidar sensor, a thermal sensor. You can even put multiple sensors on at the same time, mine comes with this rtk enabled antenna which ill talk about in a future video. But i just want you to understand that in this video im going to be giving you the most general information that you can use in order to do, aerial mapping with the most basic drone, even drones, that are under 1 000, can do what im going to Show you now there are two methods in flying a drone. The first method is to manually operate it while setting a timed image interval, say every one second take an image while youre flying the drone manually around your site. The second and more practical way is automated mission planning mission planning utilizes. The drones built in gnss receiver and by finding its location on earth can fly in a pattern that you preset in the controller. So in essence, we would be setting the parameters and telling the drone what it needs to do on the controller and then itll autonomously fly the mission for us and then return home. Thats right, theres no need to manually fly the drone, its all autonomous and im, going to show you exactly how to do it now again: im flying a dji phantom 4. So if youre using a different brand, it might be a little bit different, so just follow along and try to understand the concept as best as possible.
The first thing i like to do is take four cones and establish the home point from where my drone will take off now. Take the drone and set it in the middle of the cones now youre going to want to power on the drone. Applause next were going to be powering on the controller. Okay, the controller and the drone are communicating all right so now lets go over setting up this project and doing the mission planning now. The first thing youre going to want to do is click on plan and youre, going to be given a selection of different planning methods, depending on the type of work youre going to do. You can select any of these options, so were just going to do 2d. Photogrammetry now to the left, youll have an aerial map of where youre at. If we zoom in here – and we take a look, the red triangle is the drone, and the blue circle is the controller. Now, before we can set the mission parameters, we need to define some settings for the drone and the camera. The first one is the flying height above ground level, its automatically set to 100, but im going to change it to 25 meters. The speed of the drone is automatically set to 9 meters per second, which is fine im going to keep the shooting mode at timed shooting and after the mission is complete, i will have the drone return to home the relative height in meters im going to keep It set to zero because i want to maintain 25 feet above ground level.
Under camera settings im going to change the photo ratio to 4.3 the white balance because its a sunny day ill keep it set to sunny ill, keep metering mode set to average and ill keep the gimbal angle set to 90, so that the camera is pointing straight Down in nadir mode under advanced settings, i can adjust the horizontal overlap and the vertical overlap im going to increase this to 80 percent, and that just means that theres going to be 80 overlap between each of the images taken margin. Settings im going to manually set it to five meters and thats just going to create mapping five meters outside of my set parameters. Ill click save and im going to define my project limits. Im going to start here go here up here and over here now you can see this yellow pattern and that is going to be the pattern that the drone flies in. I can move these over if i want to create more mapping, so maybe well move that up there. Maybe maybe i can straighten this one out a little bit move this over just a tad okay. This looks great im gon na go ahead and click save and im going to name this mission. Drone job done confirm home point recorded. Okay, the home point has been recorded and everything looks good, so im gon na click on invoke. If we look in the top here, it says ready to go gnss, and if we tap here, we get a live feed of our drone camera.
All right everything looks good so now its time to take off just need to slide to execute there. It is theres the drone taking a look here. We can see the drone in its location on the map where it is in the mission. We also have a live view of the drone and what it can see from above on its camera. We can also see that the mission is 64 complete and that weve taken 80 images. So far. Applause return to home, rth operation, complete Applause and thats it taking a look at the screen. Here we get some nice information. We cover 21 000 square feet, which is just under half an acre. The flight time was 5 minutes and 38 seconds and we finished 100 of the project. I can hit confirm and if we look here, this white path is the path that the drone took, and that is how you survey using a drone. Now, if youre interested in learning how to process this data, make sure you like this video and subscribe to the youtube channel and turn on that bell notification because im going to be releasing so much content relating to drone mapping as it relates to surveying, were going To be talking about data acquisition, data processing, managing data sets doing post, processing work and creating deliverables with survey great accuracy if youre into drone mapping and surveying make sure you join our facebook group and share pictures of your projects.