Surveying with DD

Hello everyone,

I have used drones and dronedeploy for years but I’ve recently started a new job where we are using drones for surveying. The scope is to create ortho photos to generate the planametric linework for boundary surveys, etc. We will also be using limited topographic surveys.

I have heard from several people that the Phatom 4 Pro is the best for me to start with but with it out of production and it being sort of weird to tell people to start a new corporate program with eBay, what should I get? The sites are not huge, no real need for a fixed wing. I like DJI and have used a P4P since it came out in my old job.

Any advice would be appreciated. I have gone over DD’s articles but some are sort of old. I just did my first mission, a golf course in the mountains, last week and it went ok. I just want to make sure I’m doing things right.

Unfortunately your only other real option that is even close that can fly with DroneDeploy is the Mavic Pro 2. There is currently an issue with video feed on that hopefully will be figured out soon.

That said, you can fly any drone and flight software you want and still take advantage of the DroneDeploy processing and management platform. I prefer the Yuneec H520, but there are a few other options out there.

1 Like

Thanks Michael. I very much value your expertise. Do you fly the Phantom RTK? I thought I remembered maybe you had one but didn’t remember. What app do you use to fly your drone with?

I have been flying with Phantom 4 Pro’s with Emlid GNSS Hardware in a PPK scenario. I personally do not trust RTK to be 100% reliable on a drone. There’s too many things that can happen with satellites, the environment and other interferences to just assume that what you just flew had a good solid fix throughout. With the retirement of the P4P’s we are transitioning all mapping to the Yuneec H520 platform until something that makes better sense comes along. With my distrust of the stability of RTK on a drone the DJI P4RTK makes absolutely no sense to me especially when I can buy two full H520 kits with Emlid setups. If @GregO can get his P4RTK with SDK controller to work with DroneDeploy and DJI does something to allow their data to be used more easily used in a PPK scenario then I would think about it.

2 Likes

I use the P4RTK as a hybrid system, Like @MichaelL said about RTK accuracy, the P4RTK gets about 0.19 inch @ 150 feet altitude. This is good for most folks but we also throw GCPs down which will get us 0.03 inch @ 150 feet.

So I use the RTK base station to keep the flying straight with course corrections. The base station allows me to fly close to High Power Lines, Cell Towers, and in High Winds without it drifting off course. There is a video showing the P4RTK drone hovering next to a High Power Line, when turned off it drifts around (+/- 1’) and when turned on it sits there.

2 Likes

Do you fly sites differently when trying to get contours? Do you fly nadir or do the crosshatch? I was thinking I remembered you saying you did the crosshatch a lot.

1 Like

When flying for ground contours I fly nadir only and start at 225ft AGL with 80% front and 80% side overlaps. If it’s right on the edge and I want to try to keep it at one battery I will raise the altitude up to as much as 240ft and the sidelaps down to as low as 75%, but that’s where I draw the line.

oh ok great. I was thinking I needed to be a lot lower, like 150 AGL. That will help my flight time considerably!

1 Like

You can definitely fly that low, but I have not seen any advantages in creating contour maps. The downside is that it does create an opportunity for poor stitching and warping if you don’t have enough overlaps and GCP’s. Most of my maps are between 0.5 and 1.0in/px and I haven’t seen any accuracy jumps by going any lower than that.

Makes sense. I will go to 225 then. it’s .5in/pix at 150 and .8 at 225 so I don’t see the extra hours worth of effort or so to make that work it. Just using it as a quick estimate to see if we need to do another ground run topo based on limited site changes.

2 Likes

I generally fly 150’ @ 80 front / 65 side.

Getting good maps is a art form, as you go up the more side overlap will be needed. As you go down the less side overlap.

Forward overlap is free data since your already going that direction, so grab it.

If I fly flat sites I generally will fly a one pass but if I’m fly a stockpile/basin I will fly a crosshatch with high side overlaps.

I generally have 14+ photos/pixel for 65 side overlap. When I crosshatch I get up to 25+ photos/pixel.

My accuracy reports generally have 98 to 100 stitching.

With GCPs I hit 0.03", I hit a XYZ with 0’s last week, the actuals were 0.0047", I guess that’s within tolerance.

The more flights you do the more you understand which settings will effect your results.