Topic: Orthorectifying ASTER L1B imagery

Hi guys, as well as using Landsat 7 imagery to look at the Susitna glacier I also have acquired two ASTER images from 2008 and 2009, so I can compare the accuracy of both for my dissertation.

However ASTER L1B already has some spatial reference, so when I come to creating tie points in the orthorectification process the RMSE error doesn't log. Is there a way to remove the spatial reference from the L1B imagery so I can orthorectify it?




Re: Orthorectifying ASTER L1B imagery

Hey Duncan,

I don't remember having answered your post, so sorry.

You cannot ortho-rectify 1B ASTER imagery with COSI-Corr. It's not a matter of removing the spatial reference, the 1B images are already projected and resampled, and we cannot rigorously work with them. You have to get the L1A ASTER images if you want to create ortho-images with COSI-Corr.



Re: Orthorectifying ASTER L1B imagery

Is it necessary to orthorectify with Cosi-Corr in order to get accurate correlations? For ASTER imagery, I have used SILC in the past.


Re: Orthorectifying ASTER L1B imagery

Well, run the COSI-Corr correlation between ASTER images that have no expected displacement. If the displacement retrieved is indeed zero (or at least centered at zero), then you're fine. Otherwise, you need something else.