Update NOAA Level-1B file format support

[arb]

The file frmts/l1bdataset.cpp appears to have stagnated and an update is required to support NOAA-18 and MetOp-A.

NOAA-18 has been around for a few years, as has MetOp. First, these (and future) satellites need to be recognised. Second, the file format has changed slightly a few times.

It is important to check the file format version number stored in the file since files in both old and new format will exist.

The NOAA KLM Users Guide is the definitive reference. There is an Amendments page which will help you find out what has changed. ​http://www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/klm/index.htm

However there a couple of helpful documents available here: ​http://www.sat.dundee.ac.uk/AVHRR1bFormat.doc ​http://www.sat.dundee.ac.uk/AVHRR1bDiffs.doc The first may be out of date now but may be easy to read and search. The second is a short description of the main changes made to add support for NOAA-N, NOAA-Nprime and MetOp. You may want to read this document first. (The documents were obtained from a now-defunct NOAA FTP site) This page may also contain some of the required numbers: ​http://www.sat.dundee.ac.uk/satids.html

[warmerdam]

I've added Andrey as a cc: as he is the primary author of the L1B driver and may be interested in extending it. I don't anticipate address this myself in the near term.

[dron]

This is related to ticket #1569.

[dron]

Andrew,

What about some samples? I need as many samples as possible for every new file type (N, N', METOP). Or point me to the archive where these data are available. SAA archive seems to be not available anymore.

Best regards, Andrey

[dron]

Nevermind my last comment, I have found something called CLASS that seems to be a replacement for old SAA system. I have ordered few samples. Will see how it works.

Best regards, Andrey

[dron]

Well, now I have a bunch of samples, but there is another problem: I can't get the mentioned documentation. Dundee site is unavailable; KLM guide is not available also, I can see the table of contents only and getting "page not found" error when trying to read chapters.

Andrew, do you have local copies of these documents that you can send to me by e-mail?

[dron]

Ok, today Dundee site waked up, so I got the docs and added support for the new formats. I only added NOAA-17(N) and METOP-2 variants, because these are only samples I have. I can add more natellites as soon as I will get sample data for testing.

The fix is checked in with r14459.

[arb]

Thank you for the fixes (although I assume you mean NOAA-18 not NOAA-17 in the previous comment).

[arb]

Patch to l1bdataset.cpp adding support for NOAA-19 and MetOp-B

[arb]

I've just attached a patch adding support for NOAA-19 and MetOp-B (and a guess at MetOp-C which is not yet documented by NOAA).

[Even Rouault]

r24093 /trunk/gdal/frmts/l1b/l1bdataset.cpp: L1B: add support for NOAA19, METOP-B and guess for METOP-C (by Andrew Brooks, #2352)

[knutfrode]

With the applied patch, GDAL can successfully read images downloaded from Comprehensive Large Array-data Stewardship System (CLASS). However, the same images acquired through Eumetcast (of Eumetsat) are not supported by this driver.

I therefore reopen this ticket, suspecting that a small fix would do, according to the document given in the ticket description: ​http://www.sat.dundee.ac.uk/AVHRR1bDiffs.doc

[arb]

Maybe the file is not in NOAA-1B format. Please supply a URL to an example file so that we can check its format.

[knutfrode]

Here is a sample NOAA19 file (2 MB): ​https://dl.dropbox.com/u/15885758/AVHR_GAC_1B_N19_20120831060103Z_20120831060403Z_N_O_20120831075953Z

and here is a sample Metop2 file (27 MB): ​https://dl.dropbox.com/u/15885758/AVHR_xxx_1B_M02_20120830141603Z_20120830141903Z_N_O_20120830150923Z

Both should be Level 1B according to filename.

It seems to me that the lines 1572-1601 of the driver are specific to files retrieved from CLASS(?): http://trac.osgeo.org/gdal/browser/trunk/gdal/frmts/l1b/l1bdataset.cpp

[arb]

There is nothing specific to CLASS in the code.

Those files are not in NOAA Level 1B format, they are in EPS GPF Level 0 format.

Whilst the internal AVHRR format is very similar it would definitely be non-trival and very messy to add support for EPS GPF format into the l1bdataset driver. As such the ticket can probably be re-closed.

[ysid]

We are interested in this issue being fixed. I have sample data in "L1B" format that I can make available. If any developer is still following this and is willing to take a look, please respond.

Yusuf Siddiqui, i-cubed

[Even Rouault]

Yusuf, if you are interested in contracting me about this, you can send a sample at contact@… so I can have a look at what can be done.

[Even Rouault]

Opening a dedicated ticket for the issue raised by i-cubed ( http://trac.osgeo.org/gdal/ticket/5645 ) and closing that one because it mixes different issues.