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[IDD #DQQ-790553]: Request for help with LDM setup
- Subject: [IDD #DQQ-790553]: Request for help with LDM setup
- Date: Wed, 17 Jul 2013 14:16:55 -0600
Hi Wesley,
re:
> I am attempting to set up the LDM here to download data for a student-run
> weather data website. Any help in getting the data flowing would be
> appreciated.
We will be happy to help you get things setup!
re:
> I am working through the installation/configuration right now.
Very good.
re:
> Information
> =================
> Site Name: University of South Alabama Weather System
>
> Administrator:
> Dr. Wesley Terwey
> 251-461-1389
> address@hidden
>
> Hostname:
> weather.southalabama.edu
OK, first thing:
There is no reverse DNS for your machine. This can be seen by using
utilities like 'nslookup':
$ nslookup weather.southalabama.edu
Server: 192.168.72.2
Address: 192.168.72.2#53
Non-authoritative answer:
Name: weather.southalabama.edu
Address: 192.245.224.223
$ nslookup 192.245.224.223
Server: 192.168.72.2
Address: 192.168.72.2#53
** server can't find 223.224.245.192.in-addr.arpa.: NXDOMAIN
As you can see from this listing, there is no IP -> machine name
DNS mapping for weather.southalabama.edu. Please work with the
networking folks at Sough Alabama to get forward AND reverse
DNS working.
The reason that this is important is the IP address of the machine
REQUESTing data (i.e., your machine) is included in the REQUEST that
is set to the upstream machine(s) (the machine(s) that will send data
to your machine). The IP address needs to be converted into a
fully-qualified hostname (e.g., weather.southalabama.edu) before it
is matched against LDM configuration file (~ldm/etc/ldmd.conf)
ALLOW lines.
re:
> Feed Types:
> PPS
> DDS
> HDS
> UNIWISC
> FSL2
> CONDUIT
> LIGHTNING
> FNMOC
> NEXRAD2
> NEXRAD3
> NIMAGE
> =================
Some comments:
- PPS, IDS and DDS are most typically REQUESTed as 'IDS|DDPLUS':
IDS|DDPLUS == DDS|IDS|PPS
- the combination of PPS, DDS and HDS are typically
REQUESTed as 'WMO':
WMO == IDS|DDPLUS|HDS
- the combination of WMO and UNIWISC can be requested as
'UNIDATA':
UNIDATA == WMO|UNIWISC == IDS|DDPLUS|HDS|UNIWISC
- the FSL2 feed contains wind profiler and other data which
can be quite voluminous
- the CONDUIT feed is _VERY_ voluminous
Unless you have lots of bandwidth, you need to think hard
about what portion of this data feed that you want/need.
- the LIGHTNING feeds are provided as point-to-point feeds
by the top level sites that provide the data free-of-charge
to the U.S. university community:
- the NLDN lightning data is provided by UAlbany, the New York
state University at Albany
- the USPLN lightning data is provided by WSI Corporation
The contact information for each of these two feeds of lightning
data can be found in:
Unidata HomePage
http://www.unidata.ucar.edu
Data -> Lightning Data
http://www.unidata.ucar.edu/data/index.html#lightning
North American Precision Lightning Network (NAPLN)
http://www.unidata.ucar.edu/data/lightning/napln.html
Global Lightning Network (GLN)
https://www.unidata.ucar.edu/data/lightning/gln.html
National Lightning Data Network (NLDN)
https://www.unidata.ucar.edu/data/lightning/nldn.html
You will need to send an email to the contacts listed in the
last pages referenced to request a feed of lightning data.
You should indicate in your email that you are a Unidata
university participant. You should also only do this _after_
the DNS issue referenced above has been taken care of.
- like CONDUIT, the FNMOC feed can be quite voluminous, so
you will need to consider which products you want unless you
have lots of bandwidth
- the NEXRAD2 datastream is also quite voluminous; the same
comment made for CONDUIT and FNMOC applies to it
- NEXRAD3 contains NEXRAD Level III products for all NEXRADs
delivered in the NOAAPort Satellite Broadcast Network (SBN)
This feed is also voluminous and has lots of products. Some
sites have problems ingesting and processing (typically
filing to disk) all of the products available in NEXRAD3.
For reference, here is a snapshot of the volumes in the various
datastreams that are delivered by the IDD:
Data Volume Summary for idd.unidata.ucar.edu
Maximum hourly volume 23164.623 M bytes/hour
Average hourly volume 15072.076 M bytes/hour
Average products per hour 330226 prods/hour
Feed Average Maximum Products
(M byte/hour) (M byte/hour) number/hour
NEXRAD2 5260.667 [ 34.903%] 6978.108 73109.065
CONDUIT 3495.363 [ 23.191%] 5490.003 73157.109
NEXRAD3 1889.778 [ 12.538%] 2409.144 98601.239
FSL2 1520.290 [ 10.087%] 1883.157 1659.674
NGRID 1123.644 [ 7.455%] 2149.776 20112.565
FNMOC 980.239 [ 6.504%] 6781.229 2802.478
HDS 327.107 [ 2.170%] 615.243 17547.065
NIMAGE 196.234 [ 1.302%] 409.064 214.783
GEM 82.142 [ 0.545%] 518.345 935.130
FNEXRAD 70.018 [ 0.465%] 88.544 70.870
IDS|DDPLUS 49.940 [ 0.331%] 70.068 41247.283
EXP 41.478 [ 0.275%] 81.956 393.804
UNIWISC 23.499 [ 0.156%] 33.841 21.609
LIGHTNING 8.160 [ 0.054%] 23.377 346.935
DIFAX 3.367 [ 0.022%] 12.044 5.043
GPS 0.148 [ 0.001%] 1.478 1.065
re:
> Thank you very much for your help.
No worries. Please let us know when the LDM has been installed on
weather.southalabama.edu AND the DNS for that machine is fixed. At that
point we will assign you one or more hosts from which you can REQUEST
the types of data that you desire.
Last question:
- how will you be processing the data when you receive it?
What I mean is are you going to be using a Unidata-supplied package
like GEMPAK or McIDAS to visualize/analyze the data, and, if yes,
are you enough familiar with that package to know that it has
default LDM configuration settings to decode the data into formats
it can use?
Or, are you planning on "rolling your own"?
Cheers,
Tom
--
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Unidata User Support UCAR Unidata Program
(303) 497-8642 P.O. Box 3000
address@hidden Boulder, CO 80307
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****************************************************************************
Ticket Details
===================
Ticket ID: DQQ-790553
Department: Support IDD
Priority: Normal
Status: Closed