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Photogrammetry testing in Santorini with BR2

(Othonas) #1

One of our first attempts on using BR2 for photogrammetry. Here we are in Santorini trying to scan a small sandy beach

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Underwater Mapping Applications
(Rusty) #2

@Othonas - Very nice! What software did you use to process the imagery?

(Oystein Skarholm) #3

Very Nice. Same as Rusty, I am curious of the software too. Do you have any control of where the photo is taken. Like geomarking?

(Othonas) #4

Thanks Rusty and Oystein! We use Agisoft PhotoScan for generating the model. This was our first try and we didn’t use any geomarking. However we are working on a new project near Athens where we will use control points. The problem that we are trying to work around for now (as I mention in another post) is how we will get the gps position underwater.

2 Likes
(Etienne Demers) #5

I use https://www.pix4d.com/

What is nice about it is you can license it for a month only and compile all your 3d projects.

You will need a super computer though because it takes days to compile.

I cannot share results here because of NDA clauses…

That said results are comparable to the above.

(Alan Robert Buchanan) #6

I am working on a similar projects.

I have a method for time tagging the images and then preprocessing the images to insert a georef in the exif header.

Can share if you are interested

1 Like
(Patrick José Pereira) #7

There is a really good c++ library for exif in github:

1 Like
(Luis Chavez) #8

Alan,

I am working on a similar project for underwater mapping.

can you share the method you guys used to georef your images? I am using a surface GPS (lowrance) with a Gopro underwater.

regards

(Alan Robert Buchanan) #9

Luis

What’s your email address.

I can send you some details

(Luis Chavez) #10

Please send to luis.chavez@24marine.com

(John Fisher) #11

Hi BigAl

Can you share your method with me please? My email is john.fisher@cabezon.io I would greatly appreciate it. I did speak to the folks at pix4d and they recommended imaging with (2) GoPro 5 Black units for maximum overlap but nothing for GeoRef.

Thank you

John

(Luis Chavez) #12

Alan,

Hope your are doing OK

Please send the info to luis.chavez@24marine.com

regards

(Luis Chavez) #13

Alan,

email receiver.

I have been struggling with exif installation, it need many extras to make it work.

I have found an alternative, exiftool

  • here a link for installation is a simple excecutable. and read the GPS log files straight from the GPS, I will see how is it go.

  • One more detail, the EXIFTOOL also has a GUI for the users like me who love User Grafics Interfaces.

As my action camera can not do timelipase photos, I have used this video FFMPEG tool to take frames out of the video, then I will change the timetag of them in order to match the GPS timetag.

I will launch the ROV with the camera soom at the marina, to see what do we get.

regards
Luis

(Alan Robert Buchanan) #14

Ok good luck

(Jacob) #15

@luis.chavez, You can use the waterlinked or other acoustic positioning system to get the position data in the qgc/telemetry logs: https://www.ardusub.com/developers/gps-positioning.html

It’s even possible to set up lawnmower transects over polygons drawn on the map in QGC, and to trigger cameras at regular distance or time intervals, these features are not yet stable or supported though.

(Luis Chavez) #16

Thanks for the detailed explanation.

regards