Using subset in snappy and SNAP (Why different result)

Microwave Toolbox
#1

Dear all
I am working with snappy and tried to do below steps in it over one example of GRD data:
Subset
Apply orbit removal
Thermal noise removal
Calibration to beta
Speckle filtering
Radiometric terrain flattering
Terrain correction
Convert to db

In subset, I used:

def do_subset(source, wkt):
    print('\tSubsetting...')
    parameters = HashMap()
    geom = WKTReader().read(wkt)
    parameters.put('copyMetadata', True)
    parameters.put('geoRegion',geom)
    output = GPF.createProduct('Subset', parameters, source)
    return output

and then,

    ## well-known-text (WKT) file for subsetting (can be obtained from SNAP by drawing a polygon) 
    LONMIN=str(28.329)
    LATMIN=str(65.336)
    LONMAX=str(29.264)
    LATMAX=str(65.841)   
    wkt='POLYGON(('+LONMIN+' '+LATMIN+','+LONMAX+' '+LATMIN+','+LONMAX+' '+LATMAX+','+LONMIN+' '+LATMAX+','+LONMIN+' '+LATMIN+'))'

Then I did same steps in SNAP software because I wanted to compare both results.
I exactly used same geo information in SNAP software. I mean in subset from raster tool:
North latitude bound: 65.336
West longitude bound: 28.329
South latitude bound: 65.841
East longitude bound: 29.264

But I do not know why my result from SNAP are smaller than snappy. Please look at below images in SNAP (figure 1) and also QGIS (figure 2) that I put both. I would be thankful, if someone can help me.

snap and snappy2_snap2.PNG
snap and snappy2_snap2.PNG1404×790 99.5 KB

Figure1.

snap and snappy_qgis2.PNG
snap and snappy_qgis2.PNG881×721 60.5 KB

Figure 2.

#2

At the moment I have no idea why this might happen.
But I see that the SNAP result is als more rotated as the SNAPPY result, which is strange.
Which of the results matches more your expectation?

#3

Sometimes when entering numerical values in SNAP the data entry box hides left-over or pre-filled numbers. You may enter say 50, but don’t notice the hidden 09 so SNAP actually uses 50.09. Comparing the metadata for the two images may reveal some surprising values.

#4

Thanks for reply. Actually, when I use QGIS, then they are matched except my result from snappy is bigger than SNAP.
I also found this topic which I think it is related to mine.
Change in polygon size when reading a WKT with snappy - development / python - STEP Forum (esa.int)