Communications
- An active TCP/IP connection to NWS with at least T1 (1.5 Megabits/sec)
available bandwidth
- NOTE: Contact for installation of a connection is: Julie Hayes, Phone: 301-713-0864 ext 120
Email: julie.hayes@noaa.gov
- The following network configuration should be coordinated with the NWSTG:
Interface configuration on NOAANet link
Routing configuration including:
LDM receiver IP address(es) and fully qualified domain name(s)
LDM server Virtual IP
Access-lists and/or Firewall permits
- A computing platform capable of receiving 35 Gigabytes of RPCCDS product
data files per day.
RPCCDS Data Stream
All available RPCCDS product data is delivered in bzip2 compressed
'tar' archive files named as wsr88dHHMM#.tbz2 containing the actual product
data files with relative path structure. Archive contents are uniquely
identified using directory path components formatted as
"DC.radar/DS.ptype/SI.cccc/sn.####" (see: RPCCDS Product Files )
where:
- HHMM# is the archive file creation timestamp and sequence number
- DC.radar is the relative lead directory path component for the
radar product data file,
- DS.ptype is the NEXRAD product type identifier (see: RPCCDS Product Files )
- SI.cccc is the four character alphabetic site identifier code
designation (see: RPCCDS Product Files )
- sn.#### is a four digit product file sequence number for each
filename of the product stored.
The RPCCDS product data is delivered in 10 second intervals
upon receipt at the NWSTG server.
RPCCDS subscribers should choose a computing platform with the operating
characteristics consistent with their particular data processing requirements.
There are no product retransmissions. Therefore, RPCCDS product data files
missed will need to be individually pulled from the NWS ftp server farm ( ftp://tgftp.nws.noaa.gov/ ) to obtain any
missing product data. The description of the product identifiers and the radar
site location list are contained in the RPCCDS Product Files
for FTP. It is the responsibility of the RPCCDS
subscriber to detect when and if this should be necessary.
Receiver-side Software
The NWS requires the use of Unidata's Local Data Manager (LDM) software which is available for download from
Unidata.
LDM RECEIVER CONFIGURATION GUIDE
Software Configuration Procedures
STEPS
- Obtain the LDM receiver software for your receiver
platform and Operating System from Unidata.
- Perform the LDM installation procedure
- NOTE: Although it does not require administrative privileges to install or run
the LDM application software, some recommended configuration procedures
will require administrative privileges on Unix systems (e.g, the
/etc/services port setting, symbolic links in protected subdirectories, etc.).
- LDM server address: 205.156.51.69 radar3src.nws.noaa.gov
- LDM data feed type: FT27
- The etc/ldmd.conf file has the following line commented out:
#EXEC "rtstats -h rtstats.unidata.ucar.edu"
Since this is a private implementation, the following line needs to be added:
REQUEST EXP|FT27 "^wsr88d[0-9]*\.tbz2" radar3src.nws.noaa.gov
The etc/pqact.conf file has the following lines added:
FT27 ^(wsr88d.*)
FILE -overwrite -close /var/opt/ldm/NEXRD3/incoming/\1
- NOTE: You would configure the path components according to your actual
downstream LDM receiver file system configuration.
Start up configuration
We recommend the following start up settings verses the default 3600 seconds,
especially if you are using a T1 connection:
Example invocation:
- ldmadmin start -o 200 (this configuration allows long latencies but prevents
old data from being sent) or
- ldmadmin start -m 210 (this configuration limits latencies to 210 seconds) or
- ldmadmin start -o 200 -m 210 (this configuration does both)
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