20040412: IDD Data Availability (cont.)

>From: "Rob Dale" <address@hidden>
>Organization: Skywatch Services
>Keywords: 200404092020.i39KKUCT029700 IDD .com

Rob,

re: It is not our business to advise you to embark on such a venture.
Unidata has no interest in competing with the commercial 
sector for your data business.

>By .com I was not referring to a pay structure -- just making certain that a
>.com could still get a feed from a .edu which I now see is okay.

I just wanted to be clear on Unidata's position.

re: DVB-S NOAAPORT ingest system

>I do like that option - I was not aware it was that cheap.

Current NOAAPORT ingest systems use EFData SDR-54A satellite
modems which are expensive (approx. $2500 list) and have limited
bandwidth (T1 per modem).  A 4-channel NOAAPORT reception system
uses $10000 worth of EFData modems.  No wonder they are expensive!
Not only that, but the particular EFData modems are now obsolete!!

From my point of view, the reasons that the NWS is moving towards DVB-S
technology are:

- EFData SDR-54A modems are expensive, can handle limited bandwidth,
  and are now obsolete

- DVB-S technology is cheap: DVB-S receivers cost between < $100 to up
  to a couple of thousand $s (military grade).  One of the units that
  the NWS has been testing is the NOVRA S75, a unit that currently
  costs about $320.

- DVB-S technology has higher bandwidth: DVB-S can carry up to a T3 of
  data

>So other than the dish (6ft or 12ft?) that is all you would need?

You need software to read the data output from whatever receiver
you use.

>Is there anything special needed on the software side other than LDM?

Yes.  We (Steve Chiswell) developed a module we use in our NOAAPORT
ingest systems that reads the output from a module that reads from the
particular hardware doing the ingest (e.g., EFData or NOVRA S75).  The
code that reads from particular hardware was developed by Mike Schmidt
and me (PTI334 which is connected to the EFData) and Doug Smith (NOVRA S75).

A block diagram of the system is then:

  dish      PTI334/    hdlcrecv/    readnoaaport
    \       NOVRA      dvbsmi
     \
      |     +-----+    +-------+    +----+
  +---|  -> |  HW | -> |   SW  | -> | SW | ------> LDM queue -> IDD
      |     +-----+    +-------+    +----+
     /
    /

Unidata-developed ingest systems are the units supplying NOAAPORT data
(IDS|DDPLUS, HDS, NNEXRAD, NIMAGE) to the IDD.  The current
"operational" systems (Unidata is non-operational) read from a PTI334
high speed serial card which, in turn, is connected to EFData
modem(s).  Our next generation ingest systems will use DVB-S technology
as soon as the NWS turns it on operationally.  This is now scheduled
for the beginning of February, 2005.  We have had a DVB-S system
working on the NOAAPORT test broadcast (on the vacated GOES-West
channel) since last November.  I installed a system at the Universidad
de Costa Rica in San Jose, CR last month.  It (igor.ucr.ac.cr) works
like a champ!

We are contemplating making a web page that briefly describes what we
have developed and making the code available -- with NO support --.

re: IDS|DDPLUS data would be useful

>I agree - I've been playing with it today and it clearly has what we're
>looking for.

re: there has been no [UPC] effort spent in developing an LDM-6 version
that would run natively under Windows.

>There is now - I've already had people working on Linux EMWIN tell me they
>are going to look at Windows LDM instead.

Very cool!

re: Please let us and the LDM community of users know what you learn :-)

>Will do! Prior to looking at this I was able to reformat EMWIN data into a
>'simulated' LDM product by automatically adding a header / footer to each
>product with the AFOS control characters so GEMPAK software would read them,
>and using telnet I connected to the NWWS weatherwire Internet feed and
>ingested that direct into LDM. If that's of interest to anyone let me know.

You never can tell what the community will be interested in.  I can
say, however, that one person's successes invariably get adopted and
expanded by other users.  That is what an active, involved community
is all about!

>I've established a mailing list for those working on this project -- anyone
>can jump in by sending a message to address@hidden
>with 'subscribe' in the subject line.

I just subscribed to this so I can get an idea of what you are up to.

Cheers,

Tom
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