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Author Topic: Power lines and suspended objects??  (Read 5138 times)

airmap3d

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Power lines and suspended objects??
« on: July 03, 2013, 05:41:18 AM »
Question...

Does anyone know how to create accurate orthos of suspended objects, such as power lines etc?  Generally anything suspended above the ground comes out very segmented.

I understand the fundamentals of aerial photogrammetry and why this is an issue but is there a way that Photoscan can potentially correct these problems?

I am doubting that there is but just thought it was worth asking.

See attached image for an example.

Cheers.

Porly

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Re: Power lines and suspended objects??
« Reply #1 on: July 03, 2013, 11:26:08 AM »
Hello airmap,

seems like you have built geometry based on point cloud??? Or low quality?? Try to build geometry on high.

Another option is, to cut the building out of the model --> close Holes, than you can choose "one" photo that contains the whole structure in a nearly orthographic projection. The scale will be correct only in terrain region. Do not delete to much of terrain, since "close hole" geometry have to be aprox the same level of the real terrain situation.

Best regards

 

airmap3d

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Re: Power lines and suspended objects??
« Reply #2 on: July 03, 2013, 11:39:40 AM »
Hi Porly,

Thanks for the reply.  That model was actually built in high setting.  I have tried all of the others also (apart from ultra) and they all do a similar thing.

Your other option is a good one though, I will give that a go.  Could be an issue for powerlines though as they will span over numerous photos?  Luckily my business is based around mapping the bare earth, otherwise I may have been in trouble!

Thanks.

Porly

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Re: Power lines and suspended objects??
« Reply #3 on: July 03, 2013, 11:54:23 AM »
Hello,

I know the problem with powerlines. It can be a little bit frustrating... The trick is to plan you flight exact in the center of powerline axis (as most as possible), so you wont recognize the transition from one photo to another. Unfortunately, it is not possible to choose the photo that is used for orthomosaic, it works automatic. You can only disable the photos you dont want to use.. that takes time but works.

Best regards
« Last Edit: July 03, 2013, 11:56:02 AM by Porly »

airmap3d

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Re: Power lines and suspended objects??
« Reply #4 on: July 03, 2013, 01:45:26 PM »
Good point.  That makes a lot of sense.