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New Contributor
Posts: 7
Registered: ‎02-20-2017
Accepted Solution

Issue with Exterior orientation in building a DTM

deletedimageresult.PNG

 

So I have deleted all of the bad images, and ran the photogrammetry manager.

The images consist of featureless landscapes, and also dense vegetation.

 

interior.PNG

 

 

  1. Input camera details
  2. Extracted exif info from images and placed in a csv file with coordinates, yaw, kappa, roll etc.
  3. Entered the interior information, and applied to all images
  4. Exterior information was automatically generated.

I have also ran the auto-tie point generation and the results are underwhelming, despite knowing the limitations with featureless landscapes.

pointsummary.PNG

 

I'm still getting the yellow boxes for exterior. Is there something I need to consider to get this to work?

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Staff
Posts: 166
Registered: ‎06-30-2016

Re: Issue with Exterior orientation in building a DTM

If the 6 orientation parameters are good enough for the project, you can fix them by changing the status of the Exterior orientation paremeters from Initial to Fixed. You do this from the exterior orientation tab of the  Frame camera Editor.

 

Bring the Frame camera editor by clicking on the Interior orientation button (on photogrammetry ribbon tab).

 

You may not be able to extract good DTM since you said the project area is featuresless. 

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New Contributor
Posts: 7
Registered: ‎02-20-2017

Re: Issue with Exterior orientation in building a DTM

Thanks, that worked well. yeah, we know its going to be a problem, given we can't get enough tie points.

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Frequent Contributor
Posts: 153
Registered: ‎10-27-2015

Re: Issue with Exterior orientation in building a DTM

[ Edited ]

I have a bit similar case. UAV based data that works nicely in UAV tool but when brought to Imagine nothing makes sense. Orientation is picked up from UAV tools and I assume it is more or less correct. X and Y works as data lies just where it should be but still I see image frames as strange angles formatted in some sort of "flower" form

 

 

The question is - when you meet a data like this where could the problem lie and what to try.

 

The clear things I can see now is that scale at least is hugely wrong - image frames are kilometer long though they really should be less than 100m. Look angles are weird but it can be explained by fairly big Omega&Phi values for side looking scenes. Kappa rotation is not following orientation very logically but that should handle the different flight directions.

 

So question is - when you face a dataset like this - where to start figuring out assuming orientation values are correct.

 

Is it sensor model, scale, pixel sze in microns etc. What are the affect of each parameter in whole scenario. What parameter affects to what phenomena?

 

As you can see in attached jpg my "orientation" problem is more or less same as in original question.

Highlighted
Frequent Contributor
Posts: 153
Registered: ‎10-27-2015

Re: Issue with Exterior orientation in building a DTM

[ Edited ]

Actually in my case the pixel size in microns made the huge effect and I get back on track but is there any good document that explain the affect of each parameter and how to work problems out. Also the logics of Kappa makes no sense as I have thought it handles the flight direction pretty automatically but here it does not do so. My guess it is related on fact have a set up project right or lefthanded. For example are big negative kappa values valid or not for Imagine Photogrammetry?

like

So what I am looking for is a something like best practises for solving photogrammetric model when in the start they look like mine block or original posters block. So what parameters edit could be tried and what would be the expected affect from those.