Problem with SNAPHU import

Microwave Toolbox Problem Reports
1

I observed a problem with the SNAPHU import, that occurs in two variations: importing wrong data and giving the imported data a wrong band name.

The background is that I want to do correction of ionosphere for a stack of ALOS2 data. I start with a stack of interferograms and form a subset that includes my ROI and I discard the HV bands. First, I did the SNAPHU export and import from the dim containing the stack, but got weird results. To simplify the situation, I formed a subset that includes my ROI and retains only the HH bands for a selected interferogram. After exporting for SNAPHU and applying SNAPHU, the problem stated at the beginning could be observed. The first variation of the problem occured, when I browsed for the unwrapped data starting from the second tab of the import function. The generated .dim now contained a band UnwPhase… with wrong data - I do not know from where - and the name contained a wrong date (the first of the stack). The second variation of the problem occured, when I accessed the unwrapped data differently. I first used File->Import->Generic Formats->ENVI to load the unwrapped data in the Product Explorer. Then, when doing the SNAPHU import, in the second tab I took the unwrapped data from the Product Explorer. In this case, the band contained the correct data but it still had the wrong name (which can be changed over the properties of the band).
Could you please mend this?

2

For the first variation, where you end up with a band labeled ‘UnwPhase…’ with off data and a mismatched date, it seems like something’s going haywire in the data import process. And for the second, getting the correct data but with an incorrect band name, it’s a bit curious that the name doesn’t match up even though the data does.

What I would do is double-check the export settings and the steps you take during the SNAPHU export and import. Sometimes, a minor miss in the process can lead to these kinds of errors. Also, have you tried updating SNAP to the latest version? Might help