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

Hi Randy,

re:
> as a followup to my emails from last week i have included two files here for 
> you. The
> first one, DAA_20180321_1203 is a file from our npxcd machine which was filed 
> using the
> ldm.

OK.  Exactly what is the action that is filing the product?

re:
> My presumption after talking with you last week is that this is a NEXRAD 
> Level 3
> file.

It should be.

re:
> I am able to view it in mcidas as well as in IDV.

OK, so it is a viable image file.

re:
> However, when i use Metpy to view it i get the following errors:
> 
> ./daa_test.py
> Traceback (most recent call last):
> File "./daa_test.py", line 15, in <module>
> f = Level3File(name)
> File 
> "/data/users/bdf/anaconda2/lib/python2.7/site-packages/metpy/io/nexrad.py", 
> line 1577, in __init__
> assert self._buffer.check_remains(self.header.msg_len - self.header_fmt.size)
> AssertionError
> 
> HOWEVER, we found some level 3 nexrad data online which is available with a 3 
> day delay
> and that is the 2nd file i have enclosed (KLWX_SDUS81_DAALWX_etc).
> 
> This file is successfully read by Metpy w/o any issues and i can display the 
> data etc.

I would assume that the issue is a MetPy one then.

re:
> So i am left to ask the question is the ldm decoding the data from noaaport 
> in a file
> format that Metpy can read?

The LDM's primary job is to move a collection of bytes from one machine
to another.  Its secondary job, and one that is not required, is to
do something with the collection of bytes upon receipt.  Exactly what
it does with the collection of bytes is defined by one or more pattern-action
file actions.  Given this, my question to you is what is your action for
filing the collection of bytes which in LDM parlance is a product?  If
your pattern action file action is to FILE the product, then I can assure
you that the LDM is doing _nothing_ to change the product.  If, on the other
hand, your pattern-action file action is to run the product through some
other process, that process could well change the format of the product
(e.g., "decode" it).

re:
> Your emails below suggest that this should have worked.
> 
> thoughts?

I can't say anything for sure until I see exactly how your system is
filing the product, sorry.

Cheers,

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