New BUFR Table B and D descriptors for scatterometer data

[jbathegit]

Branch

Summary and purpose

This document proposes several new entries in BUFR Tables B and D for use with scatterometer data.

Action proposed

The team is requested to review and approve the new entries for inclusion in the November 2020 fast-track updates. Samples for validation can be provided upon request.

Discussions

NESDIS is proposing new BUFR sequences for use with scatterometer data, primarily from the ScatSat-1 satellite but potentially for use with other satellites as well. The level 2b sequence is modeled after the existing sequence 3-12-028, but using a modified algorithm and with different quality parameters and an extra bit needed to store the values for 0-06-034.

According to NESDIS, the proposal has not yet been reviewed by any CGMS working group, but we would welcome them to do so and provide feedback.

Detailed proposal

Please see the attachment.
ScatSat L2A+L2B proposal.docx

[SimonElliottEUM]

I can certainly pass this to the CGMS TSFDC for their comment. Typically they are given a month to comment - and no comment is taken as agreement. If I pass this to them we could have their position by the end of May 2020. Please advise

[jbathegit]

Yes Simon, please do so, as we would certainly welcome their comments, and I believe we could still complete any necessary adjustments or validations in time for the November 2020 (v35) FT release. Thanks!

[SimonElliottEUM]

Has the proposal been discussed with KNMI. They are the primary producers of scatterometer winds in Europe (including from ScatSat) but are not part of CGMS. I can arrange this if you'd like

[marijanacrepulja]

My colleague from research Giovanna Di Chiara, is in the email loop between NOAA and KNMI, so hopefully we will get feedback soon.

[SimonElliottEUM]

We should consider this also in the context of the proposal "Table D sequence for reporting scatterometer data from CFOSAT". I am a little nervous of a proliferation of somewhat similar scatterometer sequences, all originating from 3-12-208

[SimonElliottEUM]

I forwarded the proposal to CGMS TSFDC today (30/04/2020) and gave them until end of May 2020 to answer

[jbathegit]

@wmo-im/tdcf

Sample ScatSat-1 scatterometer messages are available for validation from the following URLs, as files ending in ".bufr" The corresponding ".bufr_decoded" files show what the decoded values should be.

ftp://ftp.star.nesdis.noaa.gov/pub/smcd/jpss-ait/ScatSat/L2A/
ftp://ftp.star.nesdis.noaa.gov/pub/smcd/jpss-ait/ScatSat/L2B/

[chenxiaoxia2019]

@jbathegit Hello, Jeff. I created a branch for this issue. Could you please check it? Thanks.

[chenxiaoxia2019]

@jbathegit I noticed that there are duplicate entries for 3-21-028 and 3-01-023, showing 4 times and 3 times respectively. Does the table need them or just keep one?

[jbathegit]

Thanks @chenxiaoxia2019 and yes, all of the duplicate entries for 3-21-028 and 3-01-023 (there are actually 4 of each of them) do need to be kept, because they all have different meanings based on the preceding Class 21 Table B descriptors 0-21-110, 0-21-111, 0-21-112 and 0-21-113. So please keep the overall 3-12-029 sequence exactly as it appears in the proposal.

Within branch issue-20 there were 3 new code table entries in BUFRCREX_CodeFlag_en_33.csv which had missing commas. I went ahead and corrected those, and otherwise everything else looks good and checks out OK.

[SimonElliottEUM]

I forwarded the proposal to CGMS TSFDC on(30/04/2020) and gave them until end of May 2020 to answer. There have been no objections or negative comments so we can consider that check complete.

[chenxiaoxia2019]

Thanks @chenxiaoxia2019 and yes, all of the duplicate entries for 3-21-028 and 3-01-023 (there are actually 4 of each of them) do need to be kept, because they all have different meanings based on the preceding Class 21 Table B descriptors 0-21-110, 0-21-111, 0-21-112 and 0-21-113. So please keep the overall 3-12-029 sequence exactly as it appears in the proposal.

Within branch issue-20 there were 3 new code table entries in BUFRCREX_CodeFlag_en_33.csv which had missing commas. I went ahead and corrected those, and otherwise everything else looks good and checks out OK.

@jbathegit Hi, Jeff, thanks for your quick reply and your correction.

[jbathegit]

@SimonElliottEUM Thanks again Simon for forwarding our proposal to the CGMS TSFDC, and for your follow-up!

[SibylleK]

Hello @jbathegit Jeff,
here is the output of the DWD decoding software using the entries of the branch of the first 5 BUFRs of each BUFR file from your ftp-server.
L2_ssat1_DWDdecoding.zip
At least the output of L2A250_v1r0_ssat1_s201907230017353_e201907230107104_c202005071445310.bufr seems to be the same.
I do not download the output of the other files, as they are far too big.
But all BUFR are readable and I assume the values of the different decoding software are the same.

[jbathegit]

@SibylleK Thanks very much for your help to validate this proposal!

[amilan17]

SUMMARY: Add entries to Table B Class 21, add entries to Table B Class 33, add entries Table D Category 12, add tables to Code/Flag Table 33 and add entry to Code/Flag Table 0 02 048.

[amilan17]

Approved by FT-2020-2