Alligning photos with markers failed

[ikesari]

I am a very very beginner with Agisoft.  I am working on 2500 photos of ice sheet with onle one ground control point (X,Y only).  I decided to work on chunk basis.  I created a chunk of 200 photos.  Each photo has its own coordinate (lat/long).  I tried to align these 200 photos with parameter : high accuracy and Reference for pair selection. The result was so bad, only 2 photos align.  I tried to create markers from each photo (4 at least) and did the re-allignment. The way I created markers is selecting the same features from two adjacent photos and name the macthing markers with exactly the same name.  I reset the allignment and did it again, but nothing improved.  I am wondering if I can get assistance how to improve the alignment?  All photos are overlapped with around 40-50% overlap.   Thank you.

[JMR]

You have said that have used 4 markers and given them the very same name in adjacent images. This should work.
Please make sure in the project tree that you have just one marker entry for each name. It may have happened you have renamed them to match names but in this way they are actually distinct markers. Use "place marker" instaid of "create marker" in second and sucessive instances of a marker.
Show us your photos, please

GEOBIT

[James]

You have to place the markers in at least 2 already aligned images, and also the not aligned image, so 3 in total. If you only have 40-50% overlap this might not always be possible.

[ikesari]

Yes.  I have at least 4 markers.  Let say, M1, M2, M3, M4.  In Picture 1, I created M1 and M2.  In Picture 2, I looked for the same features from Picture 1, which are M2 and M3.  I "placed marker" these points as M1 and M2.  I then "created" M3 and M4 for Picture 2.  I "placed markers" M3 and M4 for Picture 3, and so on.  So in the mid picture (in this case is Picture 2), always have 4 markers.  I then reset alignment and re-did the alignment for all unaligned pictures.  This way failed.  I then tried one-by one alignment,  I used the 2 aligned pictures, created markers, and found the same markers in adjacent unaligned pictures.  I highlighted the unaligned pictures, and re-did the alignment. Both ways failed.  Here is one kind of photos I have,   https://www.dropbox.com/s/lejp52svf0zctfq/test_image.jpg?dl=0    Thank you for all the help

[JMR]

If I understood well, there are just two points in common between two photos. This is not enough as they behave like a hinge. you'll need more, and I'd recommend 5... this is going to take long, and seems not the way to go with such a big number of photos.

I have downloaded your photo and seen that Photoscan has been able to find 82700 feature points which is beyond very good. This means you must doing something wrong unless ovelap is near 0%. So the problem in my opinion must come from a diferent source.

what can you tell about camera and lens?. Have you set a camera model with numbers that make sense?. Please, send screenshots of the camera calibration dialog showing us initial and estimated parameters.

Best,
GEOBIT

[ikesari]

I did not do camera settings.  Each photo has its own lat/long information as well as f/stop, focal length and ISO.  All values chosen for the camera was considered as reliable.  I just did import EXIF files.