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NOUS40 KWBC 031826
FOS/NOAAPORT NOTICE NO. 1612 MARCH 3... 2000
ATTENTION FAMILY OF SERVICES SUBSCRIBERS
NOAAPORT USERS
RADAR PRODUCT COMPRESSION AND TEST INGEST PERIODS
DURING JUNE 2000 THE NWS PLANS TO BEGIN COMPRESSION OF
THE RADAR PRODUCTS BROADCAST OVER NOAAPORT. THE
COMPRESSION ALGORITHM TO BE USED IS BASED ON THE ZLIB
COMPRESSION LIBRARIES. THESE LIBRARIES AND DESCRIPTIONS
ARE AVAILABLE AT THE FOLLOWING WEB ADDRESS
HTTP//WWW.CDROM.COM/PUB/INFOZIP/ZLIB.
IN APRIL 2000... NWS WILL POST ON THE NOAAPORT HOME
PAGE... ADDRESS
HTTP//WWW.NWS.NOAA.GOV/NOAAPORT/HTML/NOAAPORT/SHTML
A TECHNICAL DOCUMENTATION OF THE PLANNED NOAAPORT
ZLIB RADAR PRODUCT COMPRESSION APPROACH AND 6 SAMPLE
COMPRESSED RADAR PRODUCTS FOR USERS TO DOWNLOAD AND
TEST THEIR SYSTEM PROCESSING. THE COMMUNICATIONS
CONTROL BLOCK... WMO HEADER... AND NNNXXX IDENTIFIER IN
THE LINE FOLLOWING THE WMO HEADER WILL BE IN CLEAR
TEXT FORMAT PRECEDING THE COMPRESSED RADAR DATA FOR
EASY PRODUCT IDENTIFICATION. NOAAPORT RECEIVE SYSTEMS
WILL EITHER BE ABLE TO DECOMPRESS AT THE FRAME LEVEL OR
AFTER THE ENTIRE PRODUCT IS RECEIVED /ZLIB
LIBRARIES CAN DISTINGUISH AND DECOMPRESS INDIVIDUAL
FRAMES WITHIN A SINGLE PRODUCT FILE/. BEGINNING IN
JULY 2000 THE NWS PLANS TO BEGIN REMOVING THE ENCRYPTION
OF THE RADAR PRODUCTS ON NOAAPORT FOR LIMITED TEST
PERIODS. THE TEST PERIODS WILL BE BETWEEN APPROXIMATELY
8AM AND 4PM EASTERN TIME ON 2 OR MORE PREANNOUNCED
DATES EACH MONTH. THIS ACTION IS BEING TAKEN TO
AFFORD ALL NOAAPORT USERS THE OPPORTUNITY TO TEST THEIR
REAL-TIME INGEST AND PROCESSING OF COMPRESSED RADAR
PRODUCTS OVER NOAAPORT. THE TEST PERIODS IN WHICH
THE RADAR PRODUCT ENCRYPTION IS REMOVED WILL CONTINUE
UNTIL THE NIDS AGREEMENTS ARE TERMINATED /TARGETED FOR
SEPTEMBER 30... 2000/. ONCE THE NIDS AGREEMENTS ARE
TERMINATED THE RADAR PRODUCT ENCRYPTION WILL BE REMOVED
PERMANENTLY AND ALL PRODUCTS WILL BE OPENLY AVAILABLE OVER
NOAAPORT IN THE COMPRESSED FORMAT.
FOR FURTHER INFORMATION CONTACT
MR. MICHAEL CARELLI... NWS NIDS ADMINISTRATOR
AT 301-713-1724 EXT. 184
OR EMAIL MICHAEL.CARELLI/AT SYMBOL/NOAA.GOV
END
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