Hands-On Surveying with UAS (Drones)

Here's a video of the less-than-smooth landing of the fixed-wing drone...

[MEDIA=youtube]HLGhh-oaT1M[/MEDIA]

I will have a launch video that I'll post later after I've trimmed it down a bit.

Photos from the fixed-wing demonstration.

Here's the launch video. I decided not to trim it down after all, so you might want to skip to the actual launch.

[MEDIA=youtube]3KbqKXSeKhQ[/MEDIA]

Getting ready for the quadcopter demo.

Wendell,

It's almost as if we were there today.

Quadcopter takeoff:
[MEDIA=youtube]CtZDcLNfeHA[/MEDIA]

Quadcopter landing:
[MEDIA=youtube]PxkzKYjCoWc[/MEDIA]

Warren Smith, post: 387777, member: 9900 wrote: Wendell,

It's almost as if we were there today.

Thanks! Very cool class. I don't see myself ever surveying with drones, but it is certainly very interesting and fun. There's a lot more to it than I had expected, especially the cost!

Probably the most impressive part of it is the actual flight -- once you've setup mission planning (which is incredibly easy due to the software), you launch the drone and get it in the air, then hit Start and the software takes over. You just stand there and monitor the drone and your controller screen until it's done, then you just bring it back down to the ground. In the case of the fixed wing drone, it even lands itself.

Now they are taking questions -- one point Eric made is that you can spend $2,000 to get a basic package and get your feet wet. It will allow you to do some mapping and actually get some work done. Once you are familiar with that, then you can start looking at pro solutions like Trimble or Leica or whatever.

Full gallery with more photos available at: https://surveyorconnect.com/community/media/albums/oregon-gnss-users-group-drone-workshop-2016.1/

Wendell, post: 387722, member: 1 wrote: Fixed wing UAS can cover a much greater area and batteries last for about 50 minutes, but landing them is difficult. Greater expertise is required to operate them. For example: with quad copters, if you let go of the controls, it will just hover wherever it's at; with fixed wing, if you let go of the controls, it will just keep on going and be long gone before you know it.

Most users of fixed wing SUA would use a pre-programmed flight plan for an automatic flight, to ensure exact coverage and overlap. Trying to fly it manually for 50 minutes and get good cover would be really hard work. Such programmes normally also have an automatic landing feature, which will put it back down within a few dozen metres of the marked position. In my experience that's always a little nail biting; taking over manual control once it has turned onto the final leg is less stressful (unless you have a wide open prairie to land on).

I'm not sure what the rules are in the USA, but in Europe there is generally a safety circle limit imposed on flights, so that if you do let it go off on its own it will turn back at the safety limit and come back to circle above the take-off point (typically we would set that to be 750 metres, which allows a bit of drift on the turns beyond the legal working limit of 500 metres.

As well as the brands listed by Wendell above, you might like to look at www.questuav.com. Their SUAs are modular, so that you can swap different bodies for different payload configurations. Flight time for a 500 metre radius survey at 350 foot is about 20 minutes giving a 3cm. GSD. With proper ground control points that equates to +/- 2cm. on hard surfaces, variable on vegetation. (Depends on the filtering ability of the processing package and the density of the vegetation.) Maximum time I've had out of one set of batteries is 45 minutes, but there was quite a bit of power still to spare.

Camera size: it is important in that it controls the GSD for a given height. True, you can fly lower to achieve the required GSD with a smaller camera, but that means many more photographs and a slower flying speed to maintain the required forward overlap (difficult on a fixed wing and more flights on a rotary). If the lighting quality changes over the time of several flights then the results may suffer - orthophotos especially may be less than sparkling. We use a Sony A6000 which is 24MP - a job of 1500 photos NEEDS a really big computer to process efficiently. Shutter speed needs to suit the flying speed. Generally around 1000th second should be adequate but the lens need to be stopped down for good definition, somewhere around f6.3 to f8. Opening it right out leads to poor definition and then poor pixel matching in the processing.

The attached image shows the result of photography from 350 foot, with additional building face detail merged from a few ground photographs (you can see the line on the grass where the air and ground images change)

Wendell, post: 387698, member: 1 wrote: We're here and apparently there are about 80 folks registered for the event. Looking forward to learning more about drones, since I know very little and am intrigued. 🙂 So far, the only RPLS Today alum in attendance that I recognize is [USER=404]@John1Minor2[/USER] who is sitting right next to me.

Here is a shot of our fearless leader soaking up knowledge.

John1Minor2, post: 387986, member: 404 wrote: Here is a shot of our fearless leader soaking up knowledge.

Yeah, that's right, I'm the dude wearing the http://www.arprofessionalsurveyors.com/&apos ;">Arkansas Society of Professional Surveyors shirt (partly because it has a pocket) at an Oregon event, courtesy of our own [USER=34]@Dan B. Robison[/USER] 🙂

Nice post Wendell, thanks.

chris mills, post: 387944, member: 6244 wrote: with additional building face detail merged from a few ground photographs

What's the thing that looks like a dog running through the wall beneath the window to the right of the door?

Jim Frame, post: 388265, member: 10 wrote: What's the thing that looks like a dog running through the wall

I'm thinking it's a plastic lawn chair leaned against the wall.

Mark Mayer, post: 388273, member: 424 wrote: I'm thinking it's a plastic lawn chair leaned against the wall.

I see that now, and agree. But I rather liked the image of a dog or calf jumping through the wall.