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[Datastream #UFY-604748]: NEXRAD Level III question

Hi Randy,

re: DAA image for LWX on 20180321_1203 FILEd untouched by LDM
> Sounds good, i'm glad there is no issue with filing the data.

The only times we have seen there being problems with FILEing
products is when there is a problem on the file system where the
product(s) is(are) to be written.

As a sanity check, I downloaded the exact same DAA file as the
one you attached in a previous email from one of our motherlode
class data serving machines, and then did a byte-for-byte comparison
of it with yours, and I found that they are identical.  This
reinforces the notion that there is nothing wrong with your
DAA file.

The next thing I did was compare the beginning of DAA_20180321_1203 to
the beginning of KLWX_SDUS81_DAALWX_201803201201.  The comparison
shows that the product FILEd by the LDM still has its NOAAPort header
attached while the one you downloaded has had the header stripped off.
Here is the comparison:

$ od -c DAA_20180321_1203 | head -3
0000000 001  \r  \r  \n   4   9   5      \r  \r  \n   S   D   U   S   8
0000020   1       K   L   W   X       2   1   1   2   0   3  \r  \r  \n
0000040   D   A   A   L   W   X  \r  \r  \n  \0 252   D 314  \0  \0 252

$ od -c KLWX_SDUS81_DAALWX_201803201201 | head -3
0000000   S   D   U   S   8   1       K   L   W   X       2   0   1   2
0000020   0   1  \r  \r  \n   D   A   A   L   W   X  \r  \r  \n  \0 252
0000040   D 313  \0  \0 251 300  \0 001   ) 306 001   /  \0  \0  \0 003

My assumption at this point is that MetPy is not taking the header into
account.  You can test this by stripping the 11 header bytes off of the
DAA_20180321_1203 file and trying the resulting image in MetPy.

re:
> Is there anybody on your side that could take one of those files i sent
> you and see if Metpy can read it. It's an odd symptom that it wont.

I will stick both files that you sent as attachments to a previous
email out in a location that the MetPy guys can get to, and then send
them a note about the DAA* file not working while the other one does.

In the interim, it would be good if you tried stripping the header
off of your DAA file(s) and seeing if it(them) work in MetPy.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: UFY-604748
Department: Support Datastream
Priority: Normal
Status: Closed
===================
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