DEM alignment issue with ICP

[nahi]

Hi,
I face some issue when I am going to align two ASTER DEMs before doing differencing. I used ICP tool and my RMS between two point clouds it’s a bit high (~20-35m). I also tried point picking (choose 10-12pints) but no luck. My DEM differencing spatial pattern is not look like what I am expecting. I would appreciate if someone advise me in this regard.
Thanks

[daniel]

Before using ICP, have you roughly registered the two DEMs? And do you set the 'overlap' parameter correctly?

Don't hesitate to show us a screen capture, it's a bit hard to guess otherwise ;)

[nahi]

Hi Daniel,

Thanks for your response. I tried several ways. I roughly register the DEMS and I applied ICP but still results are same. But when I reduce overlap region to 10%, I got RMS ~1-2m but I wasn’t able to get the results I expect. Actually, what I wanna do is I align the two dem point clouds and convert it into geotiff file for estimating the difference between the both dems. I am expecting a smooth spatial patter or changes over the dem difference but my results doesn’t show any reliable spatial pattern. It would be really helpful for me if you gave some tips or suggestions.
Thanks.

[daniel]

Once again, I'll need at least a capture of the clouds, and at best the clouds themselves (you can send them to 'admin [at] cloudcompare.org')

[nahi]

Hi,

Please check your email 'admin [at] cloudcompare.org. Sent. Thanks

[daniel]

Thanks for sending the data. I'll look at it asap.