Multi-temporal Sentinel-1 data registration problem

Microwave Toolbox
#1

Hi all，
I have a question:
I processed 30 scenes of Sentinel-1 GRD data in SNAP, and the preprocessing flowchart is as follows：

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image873×41 19.2 KB

Because I want to see the changing characteristics of crops in time series images, I want to register the images. So I used the tool: Radar > Coregistration > Stack Tools > Create Stack.

After that, there are still some images with positional deviation：

image
image1138×847 52.8 KB

How do I register the image? Or is there something wrong with my previous processing steps?
Please help me.
Thanks a lot for any help!

#2

are the images from different looking angles (ascending and descending)?

If you have already geocoded the images I recommend using “Product Geolocation” as initial offset method instead of “Orbit”.