Thinking about altitudes and such, if you just always have something in view of the images that is a known size/dimensions you can scale any view/image from that. So long as your camera is on a gimbal mount and it’s shooting level, you don’t get measurement distortion from odd angles.
There are software packages out there where they stitch together all sorts of images of a place/area. They use math to calculate the vanishing point and then use it to draw a 3D point cloud very much like a LIDAR process. The methods I had read about don’t always use GPS to tie precision location and have that good down to say a 1 foot level. I do think you can dimension off the results relative to what is in the object/cloud. I had considered this for some tower mapping projects quite a few years ago, I am sure the software and methods got better over time. There were programs that would take video footage and sample out static pictures to use as part of the process. https://www.geospatialworld.net/article/3d-modeling-of-cities-can-be-done-using-images-alone/ https://expertphotography.com/create-a-3d-model-from-photos/ http://ai.stanford.edu/~micusik/Papers/Micusik-Kosecka-CVPR09.pdf https://www.zdnet.com/article/replacing-google-street-view-with-complete-3d-models-of-cities-video/ Thank you, Brian Webster www.wirelessmapping.com From: AF [mailto:af-boun...@af.afmug.com] On Behalf Of ch...@wbmfg.com Sent: Wednesday, May 13, 2020 10:06 AM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] documenting underground marks That sounds good. I would like to know if he has to be prexact on his altitudes and what kind of software he uses for the stitching. From: David Coudron Sent: Wednesday, May 13, 2020 7:38 AM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] documenting underground marks Chuck, I was just talking to a guy that uses a drone to fly construction sites. He uses a 4 MP camera and makes multiple passes. He stitches the video together with software. Each pixel in the resulting image is 1 centimeter. The construction company uses this as sort of an asbuilt. They file this and can look later to see where rebar is in the cement floor and walls. Where plumbing goes through cement, etc. He does this at multiple stages of the construction process. You could definitely do what you are asking about according to what he is doing. David Coudron | david.coud...@advantenon.com | mobile 612-991-7474 | fax 612-454-1546 Advantenon, Inc. | <http://www.advantenon.com> www.advantenon.com |3500 Vicksburg Lane N, Suite 315, Plymouth, MN 55447 | toll free 800-704-4720 <http://blog.advantenon.com/> Advantenon Blog | Advantenon on LinkedIn <http://www.linkedin.com/company/Advantenon> | Advantenon on Twitter <http://www.twitter.com/Advantenon> _____ From: AF <af-boun...@af.afmug.com> on behalf of Chuck McCown <ch...@wbmfg.com> Sent: Wednesday, May 13, 2020 8:08 AM To: af@af.afmug.com <af@af.afmug.com> Subject: [AFMUG] documenting underground marks We strive to have video and photo evidence of marks before we start digging. Sometimes we fail but most of the time when we hit something there is no paint or flags. I am wondering if a drone video would be better than our handheld phone/camcorder footage? I have never used a drone personally but have seen some of the images. It sure would be quick and easy to fly a route. Not sure the altitude you would want to use. Not sure if it would see more than the camcorder on the ground. I am thinking that the aerial view would see the paint better but the ground view would see the flags. Be good for engineering I would think. Hopefully much better resolution than Google earth. I wonder if you can correct the perspective distortion? _____ -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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