GOES-R Data Distribution Timothy J. Schmit NOAA/NESDIS – Office of Research and Applications (ORA)...
-
Upload
barnaby-wade -
Category
Documents
-
view
214 -
download
0
Transcript of GOES-R Data Distribution Timothy J. Schmit NOAA/NESDIS – Office of Research and Applications (ORA)...
GOES-R Data Distribution
Timothy J. Schmit
NOAA/NESDIS – Office of Research and Applications (ORA)
Advanced Satellite Products Team (ASPT), Madison, WI
James Gurka and Roger Heymann (NOAA/NESDIS/OSD)
and the whole GRB working group, etc
May 2004GOES User Conference
IntroductionGOES Re-Broadcast (GRB)Data compressionOther optionsSummary
What we know• Data distribution is very important• There are a large number of current GVAR reception
sites, more sites are being added• These are a combination of fixed and mobile sites. • There is a wide range of current users needs• GOES-R instrument data rates increase by
approximately two orders of magnitude over current instruments
• Data compression can help to reduce data rates (and hence distribute more data) while preserving information
What we think we know
• Data (raw) downlink most likely will be in the X-band• Data re-broadcast will most likely be in the L-band• GOES Re-Broadcast (GRB) format will be different than
todays GVAR• There will be some form of satellite re-broadcast• A tunable range of data compression options, depending
on data, is ideal.• Data compression techniques will continue to improve
What we do not know
• Data formats
• Data rate of re-broadcast data
• Contents of re-broadcast data
• Type or Amount of data compression
• Relationship between amount of data “pushed” versus “pulled”
• Etc.
• Working Group (WG) assembled to examine the nature of GOES-R high rate data to be distributed
Led by James Gurka (OSD) & Tim Schmit (ORA)
Includes senior scientists, senior engineers, and policy officials
James Gurka - WG Co-Lead NESDIS OSD
Tim Schmit - WG Co-Lead NESDIS ORA
Bill Brockman Short & Associates
Ken Carey Mitretek
Dennis Chesters NASA
Monica Coakley MIT Lincoln Lab
Roger Heymann NESDIS OSD
Eric Madsen NESDIS International Affairs
John Pereira NESDIS OSD
Thomas Renkevens NESDIS OSDPD
Dick Reynolds Short & Associates
Steve Short Short & Associates
GOES Re-Broadcast (GRB)
While no final decisions have been made, several data distribution options are being investigated for the GOES-R era.
- Various amounts of bandwidth rebroadcast via GOES
- Various amounts of data rebroadcast via other than GOES (commercial)
- Other methods (Internet, push/pull etc)
- Combination, etc.
Future GOES Rebroadcast• GRB system is extension of current GVAR system for GOES-R era
– Serve users in Near RealTime throughout western hemisphere– Current GVAR mainly only rebroadcasts radiance data; GRB may/could
rebroadcast both radiances and some products
• GRB system is payload service, separate from any direct service (LRIT, DCPI/R, EMWIN, and SAR)– GRB is needed to make a large amount of data available to a wide range of
users (both geographically and in terms of data use) in a cost efficient manner
• Main difference between GVAR and GRB:– Due to new, large data rates for the instruments currently planned for
GOES-R, the GRB system will not realistically be able to transmit all level 1b data without data compression
Possible GOES ReBroadcast System
“Data Pool”
Data compression can have applications in a number of areas:- downlink –rebroadcast - distribution - archive
“Downlink”2:1?
“Re-broadcast”6:1?
Users
Satellite Satellite
Wallops CDAS/Backup
Any GRB site
“Archive” 2:1 10+:1
“Data pool” of full GOES (the compete level 1b data) would not be compressed, nor rebroadcast. Full GOES would be available for ground-based transfers and archive.
General GRB Assumptions• User needs
– All users and applications not known – Forecasting all future users and applications uncertain
– If the data is available, user will work to gain access to it
• Users (DoD, WMO nations, academia, etc) will expect a similar (or higher) level of service
• Communications capabilities will continue to evolve – bringing improved capability, technologies, and lower cost
• Future data compression techniques will continue to improve (both lossless and lossy)
• Send out as much information (as opposed to just data) to as many users as possible while balancing cost of dissemination with the goal of maximizing the usefulness of the information
How might we move from 100 to 24 Mbps for a rebroadcast?
• Data compression is the key • Maintain a "data pool" concept for land access and archive of uncompressed sensor data
Users could then "test what is not being sent“ for their own application(s)
• One method going from ~100 Mbps to 24 Mbps: 10X for the 0.5 km visible band 6X for the "1km” bands 2X for the IR bands of the ABI 6X for the HES-IR
• Means approximately half of the band width would be used by the imager and half by the sounder; each image could be sent out
0
2
4
6
8
10
12
14
16
18
Dat
a R
ate
(Mb
ps)
"0.5 km" "1 km" "2 km"
Spatial Resolution
ABI Data Rates (Uncompressed)
Total (uncompressed) 43.5 MbpsAssuming 13-bit data and a 5-minute full disk scan mode
0.5 km visible data dominates the data rate of ABI
Total (uncompressed) 43.5 MbpsTotal (compressed) 10.4 Mbps
IR dominates the data rate of ABI after compression
0
2
4
6
8
10
12
14
16
18
Dat
a R
ate
(Mb
ps)
"0.5 km" "1 km" "2 km"
Spatial Resolution
ABI Data Rates (Compressed)
10:1 6:1 2:1
Original
MODIS 0.64 μm (0.5 km on ABI)
Compression Ratio ~9:1
Original
MODIS 0.86 μm (1.0 km on ABI)
Compression Ratio ~6:1
Simulation study shows that reconstructed brightness temperature is nearly noise-free
AIRS instrument noise
Reconstructed minus noise-free
Poster…Goldberg
Lossless Compression Comparison of Methodologies
Without pre-processing, JPEG-LS gives the best compression ratioPoster…B. Huang
Very Fast Lossy Compression JPEG-LS RMS error
A compression ratio of 5 is less than the instrument noise.A pre-processing step (right side graph) improves the performance.
Poster…B. Huang
NOAA NESDIS has investigated Alternative Dissemination Methods (ADM) for distribution of weather/environmental data by means of Internet, Commercial Space Communications, or Dedicated Landline. The ADM methods of communication are separate from communication methods utilized in Direct Readout (DR), which is a broadcast from government satellites.
12
ADM Systems View (SV–1)
May 2003 v1.0
CommercialSatellite
ADM - Alternative Dissemination Methods Center Hub
UplinkCEMSCS - Central Environmental
Satellite Computer System
SpaceDomain
Ground-stationDomain
NOAA Satellite SegmentGOES-R
N/O/PNPOESSNASA
POES
InternetFTP …
World Weather Building
DirectReadout
Users
Ground-DistributionDomain
Archival Domain
GOESI - M
Land Lines
APT/HRPT
for POES
LRD/HRDNPOESS
UserData
UserData
UserData
Processing Domain
System Interface Description (Diagram)
ADMUsers
CDA SPS - Command and Data Acquisition Sensor Processing System
UserData
GOESData
NOAAUserADMUser
Commercial
Acquisition Authority Legend
NASA
Leased by ADM
Acquired by ADM
SOCC
From Marlin Perkins
A Broad Agency Announcement (BAA) for future geostationary satellite architecture study is currently under-way.
Task Area 3: Production Generation and Distribution, Archive and Access, and User Interface Segments
http://www.osd.noaa.gov/goesr_arch_study/index.htm
Breakout Session Quesiton
• Question for each group during the break-out session on Thursday:
“Please discuss your needs for [realtime] data and product distribution, archiving and access. For example, timeliness, registration, etc. ”
end