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I acquired several Landsat 5-8 images corrected at Level 1T. I also have aerial ortophotos of the same area. From a visual assessment the co-registration between the images seems good, but I need to quantify the registration accuracy. My approach is to simply find some Check Points and calculate the average RMSE, but which transformation type should I choose to compute the residuals? In the Landsat product specifications and user handbooks I can't seem to find specific info about what they use. (I am using QGis 2.10)

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The standard for computing the registration accuracy is to consider the euclidian distance between homologous check points to estimate your RMSE (they are the residuals of the underlying model used to geometrically correct your image).

Those check points should be selected on location that are stable in time (e.g. avoid the boundaries of temporary water bodies) and (except for true ortho from high precision DSM) where there is no abrupt elevation difference with the neighbours.

As mentionned in the comments, the final RMSE is independent from the underlying model used to create the orthorectified image.

  • Thank you, but the point is that I don't know which is the underlying model used to correct the image because it was already corrected. I want to do my own independent check of the registration accuracy to see how good the registration is with images acquired from other sources, but as far as I know the Landsat metadata file only indicates the number of GCP used and the combined RMSE, not the transformation model used. So obviously when I create new check points between my two images, the residuals and consequently the mean RMSE have different values depending on the transformation I choose. – Simona Aug 13 '15 at 12:45
  • If you want the relative co-registration, you should not use a transformation. If you want to know more about Landsat processing, Landsat L1T is terrain corrected (using DEM, sensor model and GCP's from the GLS). see gis.stackexchange.com/questions/62961/… for more details. – radouxju Aug 13 '15 at 13:03

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