Playing with Drone Mapping and M2P

[Mike6158]

Out of curiosity I mapped my property using Pix4DCapture and an old program called AutoPanoGiga (no longer available) today. The results were ""not horrible". The M2P flew exactly how it was supposed to. I kind of hosed up the route when I created it. I think that contributed to the "curvy bits" along one edge. I flew at 150'. Detail isn't too bad. I can't upload it to my file hosting service because it's too big. Acreage covered was over 13 acres (actual property is slightly under 13 acres) so not a small lot. There were 370 images. It took 16 minutes to fly the route and 4-5 hours to process the files. The final file size is 557MB (jpg). A good bit of the software out there that I've found to process the images is cost prohibitive for a hobbyist. When I started this thread I was going put a link to the file here... but I don't have a place to upload it to.

 

[53-63-6f-74-74]

Panorama software won't get you a true ortho image. Have you looked at WebODM/OpenDroneMap? It's not cost prohibitive because it's open source and if you process on your own machine there is no fee. There is an installer package available for $57 if you choose not to install it yourself. The WebODM Lightning Network is available for pay-as-you-go cloud processing. If your computer is limited on RAM then you're best to use the cloud and pay the fee. You're also flying too low. I would be closer to 200 feet.

 

[Mike6158]

I just had a look at their site. My Mac has 32Gb of ram. I don't recall what RAM I have in my PC but since I run Photoshop, Premier Pro, X-plane, etc it's probably at least 32Gb. So RAM isn't an issue. 150' came from some post somewhere. I'll try 200' the next time I fly. Auto Pano Giga lets me do manual corrections but those are just a guess.

Here's a greatly reduced version, just so people can see the distortion that comes from using pano software. This is the corrected version. The only curved fence line the one on the bottom. The rest of the curvature is distortion (and that's after correction).

Pix4D is expiring soon so I don't know how much more of this I will do.

 

[Keule]

Pix4D is expiring soon so I don't know how much more of this I will do.

Have a look at Metashape. With the Standard Edition ($179), you will produce also good results.

Agisoft Metashape: Agisoft Metashape

 

[53-63-6f-74-74]

FYI the Pix4d app doesn't expire. None of the other flight apps do, either. The trial processing is the only thing that does. You can still use the apps to fly and capture, then process with other software. Metashape, formerly Photoscan, is the best software for processing. I have been using it professionally for a couple of years to produce orthoimagery and elevation models.

 

[Mike6158]

I am running my files through AgiSoft Metashape. I'm not 100% sure I'm doing it right. The software is quite a bit more sophisticated than the stuff I was using so definitely not a 1-click solution (which is fine).

I have a few more questions:
When I flew my test I did not point the camera straight down. Should I have pointed the camera down or did Pix4D do that for me?

I selected raw format before I switched to Pix4D but ended up with jpg's. Is that the default format for Pix4D or did I miss something in the settings?

I have a private pilot license so I did the Drone pilot add-on to my license. It was pretty easy compared to what it took to get my ticket. Basically my two drones are registered and I'm licensed. However, I don't have enough time on the sticks to do commercial work and I really don't know if I would want to do commercial drone work.

I have some mapping projects in mind but they are for personal use (and to share with educational concerns if they are interested). I just checked the location for one of the sites on Air Map and it doesn't show that its restricted in any way. It's not feasible to map it in the winter. Access is only possible with a 4WD truck, lots of clearance, and chains for mud and I'm not really up for the challenge (already went there once this winter and it was an ordeal). I'll have to wait for late spring.

The following is one of many sites that I'd like to map. Again, yes, I checked and it's not restricted. No hash marks, no warnings. I guess they aren't old enough (occupied in the mid-1800's). There are plenty of sites in the general area (think 200 mile radius) that are restricted that I'd like to get permission to work in but I'm not optimistic that it's even doable. Some are NPS sites. Some are National Monuments. All have a nice red hash marks over them in Air Map. I kind of get it. Prior to owning a drone I might've been opposed to drones being allowed in NPS system or at National Monuments (due to some of the dumb things people have done in the past) but now it's a little frustrating (perspective and all that jazz).

 

[53-63-6f-74-74]

I am running my files through AgiSoft Metashape. I'm not 100% sure I'm doing it right. The software is quite a bit more sophisticated than the stuff I was using so definitely not a 1-click solution (which is fine).

I have a few more questions:
When I flew my test I did not point the camera straight down. Should I have pointed the camera down or did Pix4D do that for me?

I selected raw format before I switched to Pix4D but ended up with jpg's. Is that the default format for Pix4D or did I miss something in the settings?

I have a private pilot license so I did the Drone pilot add-on to my license. It was pretty easy compared to what it took to get my ticket. Basically my two drones are registered and I'm licensed. However, I don't have enough time on the sticks to do commercial work and I really don't know if I would want to do commercial drone work.

I have some mapping projects in mind but they are for personal use (and to share with educational concerns if they are interested). I just checked the location for one of the sites on Air Map and it doesn't show that its restricted in any way. It's not feasible to map it in the winter. Access is only possible with a 4WD truck, lots of clearance, and chains for mud and I'm not really up for the challenge (already went there once this winter and it was an ordeal). I'll have to wait for late spring.

The following is one of many sites that I'd like to map. Again, yes, I checked and it's not restricted. No hash marks, no warnings. I guess they aren't old enough (occupied in the mid-1800's). There are plenty of sites in the general area (think 200 mile radius) that are restricted that I'd like to get permission to work in but I'm not optimistic that it's even doable. Some are NPS sites. Some are National Monuments. All have a nice red hash marks over them in Air Map. I kind of get it. Prior to owning a drone I might've been opposed to drones being allowed in NPS system or at National Monuments (due to some of the dumb things people have done in the past) but now it's a little frustrating (perspective and all that jazz).

You would want the camera pointed straight down and would fly a single, parallel line mission for an orthophoto, but if you are generating a 3d model/point cloud you would have a much better result with a "double grid" mission, and the camera would NOT be straight down. There are automatic and manual settings for this in Pix4d so check them before flight. You'll probably want significant overlap if you are generating models.

There is no benefit to shooting RAW format for these projects and I don't think you even can.

Below is a link to a step by step tutorial for an old version of Photoscan, but it still applies.

https://www.agisoft.com/pdf/PS_1.1%20-Tutorial%20(BL)%20-%20Orthophoto,%20DEM%20(without%20GCP).pdf

 

[Mike6158]

Looking at the EXIF of the JPG's it appears that the camera was pointed straight down. I think I'll work on getting a good orthophoto before I worry about 3D, point clouds, etc. We have a $100k laser scanner that we use for developing piping drawings and doing virtual walkthru's of construction projects at work. I work with the group that does the work but up to now I haven't paid attention to how the guy that runs the scanner and does all of the CAD work gets his results (but they are amazing). I may pick his brain a little when I get back to work.

A lot of the menu items in the Photoscan document don't seem to exist in Metashape. I stopped what I was doing this afternoon because I was pretty sure that what I had done wasn't the way to create the file I wanted to see. Metscan (demo mode) is currently generating depth maps and it appears that's going to take a while (3 hours and increasing on the time remaining). If nothing else this has been educational.

 

[Bramavic2]

You will find plenty tutorials for metashape in youtube. I'm also very new at this. You mentioned not worrying about point clouds for now, but they are a required step to get orthophotos.

For something not professional you could easily add some GCPs (Ground Control Points) to you model to get rid of those errors.
I have also tested Drone Harmony app which lets you adjust speed (slower should me more precise) and even stop the drone completely for every shot.That will bring even more precision as Mavic 2 camera has a rolling shutter which is not the best for photogrametry. If you want to know more you can read this posts by a pro using Mavic 2 for a highly precise project:

https://www.reddit.com/r/UAVmapping/comments/9cnbnv

https://www.reddit.com/r/UAVmapping/comments/ean6ho

He/She uses Ground Station Pro app that also allows to stop for every photo, but it only runs on Ipads.

 

[Mike6158]

Once I got back to work and I had the chance to discuss what I've learned (small amount that it is) with our 3D drafting guy I've decided to up the game a little. We can use the capabilities of the drone to map some of our facilities, remotely view hard to access sites, and a few other things. We have 3D software that is used with the 3D scanner that we have (all I know about the scanner is that it and the software cost well over $100k). We also have a CAD guy that is well versed in the language of 3D modeling (point clouds, etc) and is very capable when it comes to creating 2D and 3D imagery. We are going to team up in the near future and do some aerial scans. I did 0 research on the Mavic 2 Pro because none of the things that drones can do were on my radar (I had no idea in other words). The rolling shutter is a bummer. I'll read the article and check out Drone Harmony (edit) Drone Harmony is only for Android. I'll have to wait for an IOS version.

 

[Keule]

Drone Harmony is only for Android. I'll have to wait for an IOS version.

Use either Pix4d capture or MapPilot to capture images. Both are available on IOS.

 

[Bramavic2]

Once I got back to work and I had the chance to discuss what I've learned (small amount that it is) with our 3D drafting guy I've decided to up the game a little. We can use the capabilities of the drone to map some of our facilities, remotely view hard to access sites, and a few other things. We have 3D software that is used with the 3D scanner that we have (all I know about the scanner is that it and the software cost well over $100k). We also have a CAD guy that is well versed in the language of 3D modeling (point clouds, etc) and is very capable when it comes to creating 2D and 3D imagery. We are going to team up in the near future and do some aerial scans. I did 0 research on the Mavic 2 Pro because none of the things that drones can do were on my radar (I had no idea in other words). The rolling shutter is a bummer. I'll read the article and check out Drone Harmony (edit) Drone Harmony is only for Android. I'll have to wait for an IOS version.

If the IOS device you have is an Ipad you can use Ground Station Pro by DJI, it's free and should be the better alternative (I haven't tried). But the rolling shutter should only be a concern if more precision is needed. As the article says, you can compensate it by stopping, whch should make mission lasts twice as long (that might not be a issue). Depending on the size of the job, it might make sense to buy a Phantom 4 Pro as they are just back in stock at DJI, and they have a global shutter.

 

[Mike6158]

Depending on the size of the job, it might make sense to buy a Phantom 4 Pro as they are just back in stock at DJI, and they have a global shutter.

Apparently DJI makes a Mavic 2 Pro Enterprise edition that can have a camera with a global shutter, dual cameras (on IR), lights, etc. It's based on the Mavic 2 Pro. Pricing didn't look horrible

 

[Bramavic2]

Apparently DJI makes a Mavic 2 Pro Enterprise edition that can have a camera with a global shutter, dual cameras (on IR), lights, etc. It's based on the Mavic 2 Pro. Pricing didn't look horrible

I didn't know that, but it would also be wise to check the mapping apps for support for this particular camera. The others a much more common.

 

[Mike6158]

True. I found it when I searched for a camera for the Mavic 2 Pro. It occured to me (later) that the electronics and software that controls the camera are an equally important factor. At this time I'm not considering the Enterprise edition but I thought it was interesting