Issue with slope estimation

[xiyang712]

Hi kvos：
For slope estimation I used shoreline data from 2000-2023 for prediction and satellites used 'L5,L7,L8,L9',but the estimation was not too good. I searched for the reason and found that the revisit period is 16 days instead of 8 days, is it because of the reason that I chose the data after 2020? But another problem arises, as in figure 4: the range of years selected all have two satellites in operation, I hope you can help me where exactly the problem occurs.
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Figure4

[kvos]

yes something has gone wrong there, can you pls show your shoreline time-series?