This is the first time I have ordered satellite imagery via the NOAA CLASS system using the shopping cart, so I am a complete novice.

I have requested and downloaded old GOES-1 images from May 1979, but the problem is it seems the way in which the files are named perhaps and I don't know how to fix this, as it is affecting the file extension which creates something you subsequently can't open.

For example, the files I have downloaded (whether over ftp or www option) are called:


And when you save them, it says you are saving a file with the '.AREA_IR' and '.AREA_VIS' file extension, which is of course not what I want, as how do you open it?

Now, under user preferences, there are only two options for these old images - AREA format or RAW format. So, I choose .raw format which I know I can open. I request another download and I get these two files for downloading:


and, this time it wants to download a '.a' file and a '.1200' file which is obviously not what it's supposed to be.

I have tried renaming the files (especially the second set) to no avail -- I have tried .raw on the end, and I saw they use the word dataset so I have even tried .tar and .tar.gz in case it might be an archive -- nothing works.

When you go into the details of your order, they do say it is .tar file initially, but I tried to download it by adding the .tar extension upon saving even, and still nothing -- won't open in archive software.

Has anyone encountered this? How do I use these files?

  • 2
    $\begingroup$ why not just use SatPy ? $\endgroup$
    – user1066
    Commented Dec 13, 2019 at 7:40
  • 1
    $\begingroup$ @gansub I have no idea how to do anything in Python. I'm basically just looking for the images themselves in a known image format. To me it looks like the extensions are incorrect anyway - there ought to be something beyond the end of the file name - but what is the question. $\endgroup$
    – Adrian
    Commented Dec 13, 2019 at 9:35
  • $\begingroup$ When you say you could not open the files, which software did you try? Have you tried NOAA's weather and climate toolkit? ncdc.noaa.gov/wct $\endgroup$ Commented Dec 13, 2019 at 10:38
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    $\begingroup$ @gansub I endorse your idea, but unfortunately, Satpy doesn't have a reader for GOES VISSR at the moment, and I don't think anyone is developing one. Most Satpy users and developers are focussed on operational use, so current and future satellites. $\endgroup$
    – gerrit
    Commented Dec 13, 2019 at 12:57
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    $\begingroup$ @Jean-MariePrival If you can confirm that one can read GOES-1–3 VISSR data, you can post that as an answer; but it would not surprise me if those data are too old for this toolkit. $\endgroup$
    – gerrit
    Commented Dec 13, 2019 at 13:35

2 Answers 2


Unfortunately, the older weather satellite data is, the harder it is to read. Perhaps NOAA's Weather and Climate Toolkit can open it.

The old stuff usually comes in tightly packed binary formats that may or may not be well documented (these satellites were designed to take pictures of clouds for weather forecasters to use, us future generations were more or less an afterthought). Just to illustrate the difficulty: I've previously worked with data from the NOAA HIRS instrument from the late 1970s/early 1980s, and found that the headers contained a mixture of ASCII and EBCDIC information, and that some necessary calibration parameters for the thermistors on the on-board internal warm calibration target were simply lost, and that for some satellites, the available header documentation did not match what was actually in there, and I couldn't read most of the headers. Other information useful for interpretation existed in the NOAA library, but was unavailable to me due to export restrictions (ITAR).

The imager on the first generation GOES satellites is the Visible-Infrared Spin Scan Radiometer (VISSR, flown on GOES-1–3 between 1975 and 1993. A similar instrument with the same name has flown on several Japanese HIMAWARI GMS satellites between 1977 and 2000.

Pytroll is a series of Python packages to read and process satellite data. It includes Satpy, which can read a large number of meteorological satellite imager data formats. Anything that can be read by Satpy can be opened by the Satellite Information Familiarization Toolkit (SIFT), developed by the University of Wisconsin-Madison and EUMETSAT.

Unfortunately, I don't think Satpy has a reader for GOES-1 VISSR (most focus is on current and future instruments), although it can read VISSR on GMS-5 and GOES-9 since Satpy 0.43 (released July 2023). Considering the similarity of the instruments, a reader for GOES-1 VISSR should hopefully be similar to the one for GMS VISSR. For GOES VISSR, some information appears retained at CEDA, but unfortunately that appears to be lacking in the detail you would need.

If you plan to develop a reading routine (you'd need to learn Python first if you don't know it already), do hop in to the Pytroll slack for advice. There are also Pytroll workshops (normally twice a year) that are a great resource if you intend to work on a new satellite reader.

There might exist propriety software that can read this data, but unless you work at an employer that holds a license for such, that is going to be difficult to access.


Since version 0.43.0 Satpy is able to read GMS-05 and GOES-09 data in VISSR archive format: https://satpy.readthedocs.io/en/stable/api/satpy.readers.gms.gms5_vissr_l1b.html


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