Using Drones to Prepare Your Site Plan

Note: The following catalog of content covered in this webinar is time stamped to allow you to follow along or skip to sections of the video that are relevant to your questions. You can also search for content on this page using the FIND command in your browser (CTRL + F in Windows, Command + F in Mac OS.)

See our recommendations for which drones to use for your site photography on our System Requirements page.

• Intro
• Selecting Your Equipment
• Drone Applications
• Operating the Drone – Remote Styles
• Mission Type Options
• Flying at Different Elevations
• Uploading the Mission
• Post Flight – Processing the Images
• Creating Your Project
• Set Processing Area
• Output Settings
• Processing the Images
• Outputs
• Integrating with Your Workflow
• Recap of Benefits
• Photogrammetry Software
• Questions

0:00 – 3:45: Intro

Before you start: Be familiar with the pertinent regulations and safety laws. See the FAA website for more information.

 

For business-related drone use, you’ll need a certified operator.

3:46 – 6:09: Selecting Your Equipment

Benjamin uses:

• DJI Mavic-Pro drone (about $1,000)
• Pix4D professional drone mapping ad photogrammetry software to process the drone-captured imagery 

6:10 – 8:59: Drone Applications

• Aerial photography
• Site conditions
• Site contours
• Aerial video
• Marketing

9:00 – 10:19: Operating the Drone – Remote Styles

2 ways to control a drone:

• Manually (with joysticks and camera control buttons)
• Autopilot via an app on a smart phone

Benjamin tends to prefer the app because less can go wrong. However, on sites that have obstacles or otherwise require precision flying, the manual method may be better.

 

Best practices for flying a drone: 2 sets of eyes on the drone:

• One operator who is flying the drone
• One spotter who looks out for obstacles

10:20 – 12:34: Mission Type Options

Mission types available in the Pix4D software:

• Grid Mission (Best for 2D maps)
• Double Grid Mission (Best for 3D models)
• Circular mission (Best for single 3D model)

 

Selecting an imagery overlap (11:40)

12:35 – 14:34: Flying at Different Elevations

In general, the lower you fly, the better imagery you’ll get, but the longer it will take to fly the entire site.

 

Benjamin recommends staying between 100 and 180 feet in elevation.

14:35 – 15:57: Uploading the Mission

Mission database (14:55)

15:58 – 16:29: Post Flight – Processing the Images

It’s important to keep the orientation of the images consistent.

16:30 – 18:07: Creating Your Project

Recommendation: Keep your images organized by project and then by flight.

 

If you’re using a good drone, it should geo-tag all your images for you.

 

You’ll typically use 3D map templates to start your projects, but a 3D model may be a better option for smaller sites.

18:08 – 18:59: Set Processing Area

19:00 – 21:32: Output Settings

Photogrammetry uses the calculation of a series of known points to identify objects and calculate their sizes and shapes. Therefore, the higher resolution of the images, the more accurate these calculations will be.

21:33 – 23:39: Processing the Images

Just click Start, and the software will process the images.

Once the processing is finished, you’ll have what’s known as a point cloud. (21:55)

 

Discussion of ground control points (which are not necessary) (23:00)

23:40 – 27:34: Outputs

Measurements (24:00)

Measurements include distance, height, area, and volume.

 

2D outputs (25:20)

Aerial imagery photo mosaic (25:20)

You can create this mosaic using a program such as Photoshop if you want.

 

3D outputs (26:07)

• Point cloud
• 3D Mesh (obj, fbx) 
• SketchUp

 

27:35 – 41:29: Integrating with Your Workflow

Program workflows (27:50):

• Pix4D to AutoCAD to Land F/X to Rhino or SketchUp
• Pix4D to SketchUp + Undet4SketchUp (allows you to bring the point cloud directly into SketchUp)
• Plan rendering: imagery straight into Photoshop

 

AutoCAD & Land F/X output (30:26)

 

SketchUp output (32:10)

 

Question: When creating a high-quality aerial for a larger site, is it possible to have multiple flights (for example, when the need arises to replace the drone’s battery). Will the drone remember where the flight left off, and complete that flight (34:40)

Answer: Generally yes, but it will depend on the drone and software you’re using. Try to keep your settings (such as elevation) consistent on larger sites.

 

Question: Can I use drones to create a legal site survey? If so, what are the process and requirements? (37:25)

Answer: As far as Benjamin knows, you cannot use drones to create a legal survey (in the state of Utah, where he lives). It might be allowable to have a surveyor stamp the survey, but he isn’t sure of the legality of that practice.

 

Question: What level of processing capacity does your computer need for drone imagery processing? (39:08)

Answer: A powerful computer, but not necessarily a ridiculously powerful one. Ultimately, it will come down to processing time. Less-powerful computers will take longer to process the images. If your computer can handle Lumion, it will likely be able to handle this type of drone image processing.

41:30 – 43:29: Recap of Benefits

Benefits:

• Accuracy of 3/4 inch (2 cm)
• High-resolution imagery
• Oblique imagery
• Accurate imagery of the height at which the viewer might be
• 3D model/point cloud import directly into your design software
• DEM for GIS import

43:30 – 45:49: Photogrammetry Software

• Paid (all prices as of March 2018)
• Pix 4D ($8.700 purchase / $350 per month
• 3DF Zephyr ($4,200)
• 3D Survey ($3,600)
• AgiSoft PhotoScan ($3,500)
• ReCap 360 ($300 per year)
• Skycatch ($199 per month)

 

Free

• Drone Mapper
• Open Drone Map
• WebODM

 

Other software:

• Hangar 360: Mobile app to create drone-based 360 panos (free)
• DJI Ground Station Pro: Drone control app for DJI drones (free)
• Autopilot: Drone control app photo/video capture ($20)

45:50 – end: Questions

Question:How do you compensate for wind? (46:15)

Answer: If flying manually, you’ll need to make adjustments manually. If using an app, the app will adjust automatically. Benjamin does not recommend flying drones in winds above 30 miles per hour. Note that compensating for wind will take up more battery power. For videography, you may not be able to get the imagery you want above a certain wind level.

 

Question: Any less-expensive drones you can recommend? (48:55)

Answer: You have several options, but you get what you pay for. You may be sacrificing features such as ability to interface with an app, camera quality, or even build quality. You can also build your own drone if you have the expertise. Note also that drones will become less expensive in general over the years.

 

Question: Can AutoCAD read point clouds? (51:02)

Answer: Benjamin isn’t sure about that, but you can bring it into SketchUp and point cloud readers.

 

Question: How much time is typically spent for manual processing of the data? (51:45)

Answer: It will depend on the size of the site, but it’s pretty quick. For example, for a site that’s between 5 and 10 acres, you probably won’t spend more than an hour.

 

Question: Do you use Mac or Windows? (53:30)

Answer: Pix 4D does not have a Mac version. However, AgiSoft does have a Mac version. See the Comparison of Photogrammetry Software article on Wikipedia for a comparison of several software options.

 

Question: How much time and money is involved in gaining certification? (54:58)

Answer: Benjamin’s students take a semester-long class from the aviation department at Utah State University, but several online programs are available. The operator test costs between $100 and $150. Benjamin compares it with ham radio certification – about a month of studying, and then taking the test.

 

Question: In your experience, is there a lot of interference from power lines, utilities, etc. (57:30)

Answer: Generally, no. Just don’t run into them!

 

Question: Do you use neutral density (ND) filters at all? (58:10)

Answer: No, he doesn’t use filters at all. Information about ND filters

 

Question: Is the FAA operator license nationwide? (59:25)

Answer: Yes, it’s nationwide. You’ll just need to take the test at a certified testing center.