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Re: your mail

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  • Subject: Re: your mail
  • Date: Thu, 22 Jun 2000 15:11:09 -0700 (PDT)
Dear Steve Chiswell,
Thanks for the quick reply.  I have bought "stroke level
data" from Geomet Data in the past, and so I know
they store the data at least to the millisecond.  It
is interesting that they dont give it that way to you.
Sincerely,
Bob Holzworth
************************************************
Prof. Robert H. Holzworth
Graduate Program Advisor in Geophysics
University of Washington
Room 202 ATG Building
GEOPHYSICS 
Box 351650                   
Seattle, WA 98195-1650, USA 
************************************************
address@hidden 
http://www.geophys.washington.edu/People/Faculty/bobholz/
************************************************
206 685 7410 (office & voice mail)
206 685 3815 (fax)
************************************************


On Thu, 22 Jun 2000, Unidata Support wrote:

> Date: Thu, 22 Jun 2000 15:41:04 -0600
> From: Unidata Support <address@hidden>
> To: Robert Holzworth <address@hidden>
> Cc: address@hidden, address@hidden
> 
> 
> Robert,
> 
> The nldn files on the IDD transmit a field for "nanoseconds", which
> is used to create the milliseconds field that DCNLDN is storing.
> Looking at the data that is being transmitted, the nanoseconds value
> is always appearing as an even tenth of a second multiple, eg:
> 
> sec 961704003 nsec 300000000
> 
> Thus, converting the nsec value to 300 milliseconds is not losing any
> presicion in the decoding at your end. Rather, it is already being
> coded as a number with 1/10s resolution when the data file is
> created by the provider.
> 
> We will see if the providers of our NLDN data stream can give us more
> information on how the data is being processed to create the IDD
> datastream products and if the data values are being truncated.
> 
> Steve Chiswell
> Unidata User Support
> 
> 
> 
> 
> 
> 
> >From: Robert Holzworth <address@hidden>
> >Organization: UCAR/Unidata
> >Keywords: 200006221835.e5MIZXT27254
> 
> >Re: NLDN time resolution in data to UW
> >Dear Unidata,
> >I am a professor at the Univ. of Washington and Harry Edmon
> >(Atmospheric Sciences Department) suggested you may be able 
> >to answer my question.  
> >We get NLDN from you on a regular basis, but it seems to have time
> >resolution only to the 1/10 of a second level (0.1s), right?
> >
> >How can we get millisecond resolution?  The data files you
> >send have the time with space for the digits to the
> >millisecond, but the 10ms and 1ms digits are always zero:
> >time: 23.100  instead of 23.132 for an event at 132 ms after
> >the 23rd second.
> >
> >I realize this will make our data set expand somewhat because
> >multiplicity will then always be 1, I guess.  However, for
> >experiments I am doing this month and next we will need
> >stroke-level NLDN data.  
> >
> >Is it possible to increase the time resolution for us?  If
> >this is a problem for the routine processing, would it be
> >possible to get stroke level data after the fact for
> >particular subsets of the data?  
> >
> >Thanks,
> >Bob Holzworth
> >************************************************
> >Prof. Robert H. Holzworth
> >Graduate Program Advisor in Geophysics
> >University of Washington
> >Room 202 ATG Building
> >GEOPHYSICS 
> >Box 351650                   
> >Seattle, WA 98195-1650, USA 
> >************************************************
> >address@hidden 
> >http://www.geophys.washington.edu/People/Faculty/bobholz/
> >************************************************
> >206 685 7410 (office & voice mail)
> >206 685 3815 (fax)
> >************************************************
> >
> 
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