Hello,
is there a way to get fragments of original Sentinel-2 images in UTM CRS?
When I configure receiving them in UTM I see that they were reprojected (from EPSG 4326?) and differ from original scenes obtained from Copernicus Dataspace.
The reprojection introduces errors…
Regards
Ints
If you use the same CRS as the one in the original image (i.e. UTM with the right datum), there is no reprojection happening. You should also make sure to align the grid correctly, but with UTM this is easy.
That is what I expected.
But somehow the images for Copernicus Dataspace and Sentinel-Hub differ.
See them at: Nextcloud
File “RigaC-20240511Shub.tiff” is obtained from Sentinel-Hub, the other one is extracted from the SAFE archive.
Both GeoTIFFs contain only 10 bands (10m and 20m resolution ones).
Request is as follows:
request =
‘{
“input”: {
“bounds”: {
“properties”: {
“crs”: “http://www.opengis.net/def/crs/EPSG/0/32635”
},
“bbox”: [
322510,
6315210,
324110,
6316120
]
},
“data”: [
{
“type”: “sentinel-2-l1c”,
“dataFilter”: {
“timeRange”: {
“from”: “2024-05-11T00:00:00Z”,
“to”: “2024-05-11T23:59:59Z”
}
}
}
]
},
“output”: {
“width”: 160,
“height”: 91,
“responses”: [
{
“identifier”: “default”,
“format”: {
“type”: “image/tiff”
}
}
]
}
}’
What could go wrong?
Ints
Checking these two samples, they seem same to me, pixels seem to be aligned, some random value as well.
What specifically should I see?
Sorry, I uploaded the wrong file- please compare ‘RigaC-20240511Snap.tiff’ with ‘RigaC-20240511Shub.tiff’ now.
Look at the bridge and you will notice distortions.
I was allowed to upload images now so you can see them below:
RigaC-20240511Snap.tiff (287.7 KB)
RigaC-20240511Shub.tiff (287.7 KB)
Just to double check - did you perhaps also compare the exact product, SAFE, directly imported in QGIS? Best to compare Sentinel Hub with that one, rather than something produced with SNAP.
If so, and you still see differences, do please send SAFE id.
Yes, sure, I did and it is fine in SNAP and QGIS:
S2A_MSIL1C_20240511T095031_N0510_R079_T35VLD_20240511T103438.SAFE
One thing I notice is the following:
“width”: 160,
“height”: 91,
The height of your area is 90, not 91. This might be an issue.
That said, how exactly do you see that “they were reprojected (from EPSG 4326?) and differ from original scenes”?
It seems that you are approaching the point.
To my understanding, the height is calculated from BBOX:
(6316120-6315210)/10 = 91
As to reprojection, that was just a guess.
I just saw the distortions and (apparently wrongly) assumed that they are the result of reprojection. Sorry for confusion.