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[LDM #VST-440496]: NLDN timing

Hi Takeshi,

re:
> Thanks for your quick reply.

No worries.

re:
> I dumped a 1-day data set into a text file and sorted it according to time.
> Then, I found that every other seconds are missing. Given the nature of
> lightning strokes, this does not represent real data.

Very strange indeed.  I just did a dump of today's NLDN lightning data
signal strengths, and I see the same pattern of report times alternating
seconds (except when there is a difference of more than 2 seconds between
events).

re:
> Can you make sense of it?

I have no explanation for the inexplicable regularity in the indicated times
(NB: we don't create the data, we just relay it in the IDD).  The investigations
I have done in the past basically were comparisons between the NLDN locations
and polarities and NAPLN locations and polarities over time frames of a few
minutes to several hours just to make sure that the two different datasets
(one contains stroke data and the other contains flash data) were essentially
conveying the same information.  I have never looked at the data as closely
as you; sorry.

re:
> By the way, I have an entry for NLDN in "pqact.conf" like the one below
> 
> LIGHTNING 
> ^([12][0-9][0-9][0-9])([0-3][0-9][0-9])([0-2][0-9])([0-5][0-9])([0-5][0-9])
> FILE    -close  /home/ldm/data/\1\2/\1\2\3\4\5.dat

OK.  This is virtually identical to the one I use for the ldm-mcidas 'lgt2md' 
decoder
I wrote.  Just so you know, the LDM file action will not affect the information
inside of the products it is filing.

Comment:

Perhaps you should get the USPLN data and do your own inter-comparisons.  Both 
data
streams are free-of charge.  Please refer to the web pages we host for the two 
datasets
for more information:

NLDN - Vaisala
https://www.unidata.ucar.edu/data/lightning/nldn.html

NAPLN - WSI
https://www.unidata.ucar.edu/data/lightning/napln.html

Cheers,

Tom
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Ticket Details
===================
Ticket ID: VST-440496
Department: Support Datastream
Priority: Normal
Status: Closed