Meaning with number of tile rows and columns in phase unwrapping

[marjanmarbouti]

@marjanmarbouti

Number of tile rows:1

Number of tile columns:1

Thanks for reply @ABraun .

I found this explanation

SNAPHU parameters

I don’t know of a thread online explaining the column and row overlap, so I will try to explain some here. There is an option in SNAPHU to divide a large interferogram into tiles with some number of rows and columns in the division. With the tile option, it runs the SNAPHU optimization on each tile separately, which uses less memory and time than doing the optimization on the full interferogram. At the end, it takes the unwrapped phase from each tile and uses the overlap with adjacent tiles to e…

That it explained:

With the tile option, it runs the SNAPHU optimization on each tile separately, which uses less memory and time than doing the optimization on the full interferogram. At the end, it takes the unwrapped phase from each tile and uses the overlap with adjacent tiles to estimate an overall offset for each tile relative to the other tiles and prepare a final unwrapped phase for the full interferogram.

And then you mentioned:

Tiles help to reduce unwrapping errors, but the edges need high overlap to be merged seamlessly.

So, I think if we have more tiles (I mean 10 in 10 tiles instead of 5 in 5 tiles), then it means our unwrapped result will be more accurate because it takes the unwrapped phase from smaller tile…is not it? So, then if we have error for any of this tiles, then that error would be for a smaller tiles in comparison with bigger tiles?

2. So, just imagine an interferogram is 3000*4000, so then based on SNAPHU Unwrapping - #421 by ABraun,

How we can know ‘number of tile rows and colums=10’ is better or ‘number of tile rows and colums=5’? is there any way to find optimized number?

3. Regarding your question:

What value did you set for overlap?

I put it as ‘zero’ because it was suggested by SNAP defaults.

But then why it worked with ‘number of tile rows and columns=1’ and with overlap 0? But did not work with ‘number of tile rows and columns=10’ and with overlap 0?

I think I still do not get what this overlapping is doing……

4. As you can see I got result with 1 in 1 tiles and overlap zero but how can I know this result is OK? So, maybe if I tried 10 by 10 tiles and 100 overlap then I got better result!!! How can I which result is better? more tiles or less tiles?