[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[IDD #WHP-619598]: NLDN access
- Subject: [IDD #WHP-619598]: NLDN access
- Date: Fri, 13 Jun 2008 12:17:29 -0600
Hi Lee,
re:
> I can't find anywhere on the Unidata website the binary format
> specifications for the FT14 feedtype. Do you know where those might
> be? I contacted David Knight at SUNY Albany, but he does not have
> that information, and recommended I talk to you.
Here is a description of the binary NLDN records received contained in
the IDD NLDN datafeed with sizes and a short description of the various
fields:
** NLDN record:
** size value description
** -------+---------+----------------------------------------------------
** char[4] NLDN 'NLDN' marks the start of record
** int tsec time in seconds since 1970
** int nsec nanoseconds since tsec (seems to be thousandths)
** int lat latitude [deg] * 1000
** int lon longitude [deg] * 1000
** short fill padding
** short sgnl signal strength * 10 [150 NLDN measures ~= 30 kAmps]
** short fill padding
** short mult multiplicity [#strokes per flash]
** char fill padding
** char semimaj semi-major axis
** char eccent eccentricity
** char angle ellipse angle
** char chisqr chi-square
> The website you linked to suggests that there is a way to immediately
> convert the feed to netCDF via a decoder?
The comment made in http://www.unidata.ucar.edu/data/lightning.html:
"When a lightning data packet is received by an LDM server, a decoder may
be automatically invoked to convert the NLDN-native format to, for example,
a Unidata netCDF file. Unidata and SUNY have established an IDD feedtype,
NLDN FT 14, for this data stream."
was meant to be illustrative. We do not currently provide a decoder that
converts the NLDN broadcast format into netCDF.
> That would probably be
> easiest, but just getting the binary format specification for the
> native NLDN feedtype would be fine, too.
Please see above.
> Thanks so much,
No worries.
Cheers,
Tom
****************************************************************************
Unidata User Support UCAR Unidata Program
(303) 497-8642 P.O. Box 3000
address@hidden Boulder, CO 80307
----------------------------------------------------------------------------
Unidata HomePage http://www.unidata.ucar.edu
****************************************************************************
Ticket Details
===================
Ticket ID: WHP-619598
Department: Support IDD
Priority: Normal
Status: Closed