NOUS41 KWBC 281050
AAA
PNSWSH
Technical
Implementation Notice 12-45, Amended
National Weather
Service Headquarters Washington DC
650 AM EDT Fri
Sep 28 2012
To: Subscribers:
-Family of Services
-NOAA Weather Wire Service
-Emergency Managers Weather
Information Network
-NOAAPORT
Other NWS Partners, Users and
Employees
From: Timothy McClung
Chief, Science Plans Branch
Office of Science and Technology
Subject: Amended Date: Addition of Alaska Region NPP
VIIRS
Imagery to NOAAPORT Test Channel
Effective
October 10, 2012
Amended to
reschedule the implementation to Wednesday, October
10,
2012, to allow for additional testing.
On or about
Wednesday, October 10, 2012, beginning approximately
1500 Coordinated
Universal Time (UTC), high resolution imagery
from the Suomi National
Polar-Orbiting Partnership (NPP)
satellite will be broadcast across the NOAAPORT
satellite
broadcast network. This addition will consist of a
limited set of
NPP Visible
Infrared Imaging Radiometer Suite (VIIRS) imagery
covering the Alaska region. The imagery stream will
be provided
by the NOAA National Environmental Satellite,
Data, and
Information Service
(NESDIS) NPP Data Exploitation (NDE) system,
based on NPP VIIRS imagery Environmental Data
Records (EDRs).
The new NPP VIIRS
imagery products will be transmitted across a
test channel of the NOAAPORT satellite broadcast
network.
-Digital Video
Broadcast (DVB) packet identifier: 105
-Multicast
address: 224.0.1.5
-Port number:
1205
-SBN Data Stream
field setting in their frame-level headers: 7
NWS anticipates
this NOAAPORT channel will be populated with
additional polar-orbiting satellite imagery. For
clarity, this
channel will be referred to as the POLARSAT.
The Alaska region
NPP VIIRS imagery will, in general, be within
the following latitude-longitude box:
Lower/Southern
Latitude: 45 degrees North
Upper/Northern
Latitude: 75 degrees North
Left/Western
Longitude: 120 degrees East
Right/Eastern
Longitude: 120 degrees West
This initial set
of imagery products will be based on three NPP
VIIRS I channels,
the horizontal resolution of which, at nadir,
is approximately 375 meters.
The imagery
products will be formatted in netCDF4, but compressed
via gzip. Like all
NOAAPORT products, each file will have a plain
text WMO heading at its start. These headings are
listed below.
TIPB01 KNES -
Imagery Channel 1 (0.64um)
TIPB04 KNES -
Imagery Channel 4 (3.74um)
TIPB05 KNES -
Imagery Channel 5 (11.45um)
The "P"
in the third character place of the WMO Heading
distinguishes this NPP-VIIRS imagery from pre-existing
NOAAPORT
satellite imagery.
To access these
products, users should take the following steps:
-Read beyond or
strip off the WMO heading
-Decompress the
resulting product, e.g., via gunzip
-Use a netCDF4
reader, e.g., a decoder that invokes the Unidata
netCDF4 software package
Each product will
consist of one granule of VIIRS imagery for a
single channel. The VIIRS granules will cover
approximately 86
seconds of data, roughly 5 degrees or 556 kilometers
of along-
track geographical extent.
Unlike existing
NOAAPORT satellite imagery, formatted on
prescribed maps, each NPP VIIRS imagery granule will be
uniquely
located. Geolocation
information is contained in each product
file. The geolocation
information consists of three 1541-
dimension arrays of latitude/longitude pairs that
correspond to
the granule edge (first column), granule
centerline, and granule
edge (last column), with all three arrays
oriented along the
satellite track.
Given the fixed
resolution and gridded Ground Track Mercator
representation of the VIIRS imagery, only these three
columns of
geographical information (latitudes and longitudes) are
required
to map the imagery. This reduced geolocation information can be
interpreted based on the VIIRS Ground Track Mercator
imagery
algorithm (fine 375 meter resolution version) for
accurate
georeferencing. Related information (though not specific to
the
NOAAPORT stream
of NPP VIIRS imagery) can be found in the
following document: "Joint Polar Satellite System
(JPSS)
Operational
Algorithm Description (OAD) Document for VIIRS Ground
Track Mercator
(GTM) Imagery Environmental Data Record (EDR)
Software,"
Revision A, January 18, 2012, (e.g., section 2.0.4).
The NOAAPORT feed
of NPP VIIRS imagery is provided across a test
channel of the satellite broadcast network. This
NOAAPORT channel
is under test and evaluation. Product availability across this
channel is nonetheless expected to approach or meet
that of
operational/baseline data (i.e., greater than 95% data
availability). If the experimental period is successful,
NWS
intends to transition this NOAAPORT stream to full
operational
posture in early 2013.
For questions
regarding the scientific or technical content of
the NOAAPORT NPP VIIRS imagery feed please
contact:
ESPC Help Desk
Suitland, Maryland 20746
Phone: 301-817-3880
Email: ESPCOperations@noaa.gov
For questions
regarding the NOAAPORT activation or distribution
of these data sets please contact:
Brian Gockel
NOAA/NWS Office of Science and Technology
Phone: 301-713-0304 x158
Email: Brian.Gockel@noaa.gov
NWS Technical
Implementation Notices are online at:
http://www.nws.noaa.gov/om/notif.htm
$$