I downloaded images with yesterday with Copernicus and get the following error message on SNAPS:
java.util.zip.ZipError: zip END header not found
My old images are working fine.
Are you able to unzip the files with tool some zip tool?
Maybe the download didn’t work well?
Is there a way to get file sizes or checksums from Copernicus? NASA’s OBDAAC has a search tool that generates lists of files with the shasums which allows you to check downloads before trying to process them. I find some complicated workflows get tied in knots when given bad inputs that can take time to unravel (and can send users down rabbit holes trying to fix non-existent bugs), so ensuring that input data are not corrupt saves time in the long run (and allows us to get away with programs that don’t respond well when given bad data).
Dear Marpet,
With 7-zip I got the message: unexpected end of data
With winRar: the file is in unknown format or damaged / unexpected end of file
Five imagens with the same problem.
So, it seems the download went wrong. I suggest to try again. Maybe you have more luck next time. If it is still not working you should report this to eosupport@copernicus.esa.int
@gnwiii a MD5 integrity check can be performed when the dhusget script is used ( Open Access Hub - Scripting)
But I think the MD5 is not available when using the webpage for downloading the data.
Dear Marpet,
Thank you
When a batch of downloads fails at the same time it is possible that the downloads have been replaced by a text or html document with error messages. If a download terminated early you may get a partial file and the size alone will indicate a problem, but I have also had files with blocks replaced by “NUL” values so you should look for ways to verify a checksum.
Linux and macOS have “file” command that inspects the first part of a file and makes a (usually correct) guess about the contents. On Windows you can get the “file” command from git’s bash terminal, Cygwin, or WSL2. Some downloaders have an option to change the extension to match the file type. You may be able to open html files with a browser to read error messages, and text files with Notepad or other simple editor. Some sites quarantine downloads and the message will tell you what is needed to retrieve your files. I have also seen messages that the remote host has been blacklisted or that some AV scanner could not process the file.
After several downloads with the same problem, I got the same images in ASF Data Search. The images there did not present any problems.
Good that you have found a workaround.
Maybe these products are already corrupted on the server. But actually, this is unlikely.
Would be good if you let Copernicus know about this. They can investigate and probably fix it.
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ok, I sent a message to eosupport@copernicus.esa.int
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