Coordination Group for Meteorological Satellites - CGMS
NOAA Transition to New Direct
Readout Systems for
GOES-R
Presented to CGMS-44 WGI session, agenda item 3.2
CGMS-43-NOAA-WP-03
Coordination Group for Meteorological Satellites - CGMS
Getting Ready for the GOES-R Series:
Transitioning from GVAR to GRB
CGMS-43-NOAA-WP-03
Slide: 2
Coordination Group for Meteorological Satellites - CGMS
GOES-R at Test Location – First 12 Months
CGMS-43-NOAA-WP-03
Slide: 3
Coordination Group for Meteorological Satellites - CGMS
Transitioning from GOES-13/14/15
to GOES-R
• Improved data products for hemispheric retransmission
– “GOES Rebroadcast” (GRB)
– Faster full disk images: 5 minutes (Mode 4) - 15 minutes (Mode 3)
– Full set of Level 1b data: 6 GOES-R instruments (16 ABI channels)
• Requires new antenna, receiver hardware, and
processing system to handle the new data volumes
– Receiver frequency shift from 1685.7 MHz to 1686.6 MHz
– Dual circular polarized signals
– Going from 2.11 Mbps (GVAR) to 31 Mbps (GRB)
• GRB down link specifications and data format
specifications:
– http://www.goes-r.gov/users/grb.html
• GOES-R launch – 13 Oct 2016
CGMS-43-NOAA-WP-03
Slide: 4
Coordination Group for Meteorological Satellites - CGMS
Transition from GVAR to GRB
GOES Variable (GVAR)
GOES Rebroadcast (GRB)
Full Disk Image
30 Minutes
5 Minutes (Mode 4)
15 min (Mode 3)
Other Modes
Rapid Scan, Super Rapid Scan
3000 km X 5000 km
(CONUS: 5 minute)
1000 km X 1000 km
(Mesoscale: 30 seconds)
Polarization
None
Dual Circular Polarized
Receiver Center Frequency 1685.7 MHz (L-Band)
1686.6 MHz (L-Band)
Data Rate
2.11 Mbps
31 Mbps
Antenna Coverage
Earth Coverage to 50
Earth Coverage to 50
Data Sources
Imager and Sounder
ABI (16 bands), GLM, SEISS,
EXIS, SUVI, MAG
Space Weather
None
~2 Mbps
Lightning Data
None
0.5 Mbps
CGMS-43-NOAA-WP-03
Slide: 5
Coordination Group for Meteorological Satellites - CGMS
GRB Downlink Characteristics
•
•
Input Center Frequency: 1686.6 MHz
Content (specified for each of two polarization channels: LHCP, RHCP)
•
Data rate
•
Compression - Lossless compression required
•
Format
•
Coding
•
•
Modem Required C/No (dB-Hz): 78.6
Maximum Demodulator Required Eb/No (dB) for 1x10-10 BER:
•
Minimum Antenna System G/T (dB/K) : 15.2 db/K (at 50 Elevation)
– L1b data, QC data and metadata: ABI, SUVI, EXIS, SEISS, MAG
– L2 data, QC data, metadata: GLM
– GRB Information Packets
– 31 Mbps maximum data rate
– 15.5 Mbps instantaneous maximum for each polarization channel
– Downlink link margin: 2.5 db
– JPEG2000 (ABI, SUVI) and SZIP (GLM); EXIS, SEISS and MAG data will not be compressed
– Outer Frame Format: DVB-S2
– Inner Frame Format: CCSDS Space Packet
– BCH + LDPC (2/3) for 8-PSK and LDPC (9/10) for QPSK
– 3.7 dB (8 PSK); 3.9 dB (QPSK)
CGMS-43-NOAA-WP-03
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Coordination Group for Meteorological Satellites - CGMS
GRB Ground Antenna Sizes
GOES-West
GOES-East
NOTES:
1. Calculations based on available data as of May 2011
2. Each antenna size is usable within the indicated contour
3. Rain attenuations included are:
1.3/1.6/2.0/2.2/2.5 dB (3.8 to 6 m)
4. An operating margin of 2.5 dB is included as the dual polarization isolation is likely to
vary within each antenna size area
CGMS-43-NOAA-WP-03
Slide: 7
Coordination Group for Meteorological Satellites - CGMS
GOES-R System Architecture
CGMS-43-NOAA-WP-03
8
Coordination Group for Meteorological Satellites - CGMS
GRB Resources for Users
• GRB Downlink Specification Document for Users
Provides GOES Rebroadcast radio frequency
downlink characteristics, to enable the user
community to develop GRB receivers
– http://www.goes-r.gov/resources/docs.html
• GOES-R Product Users Guide (PUG)
– Describes the format and content of GRB data
– http://www.goes-r.gov/resources/docs.html
CGMS-43-NOAA-WP-03
Slide: 9
Coordination Group for Meteorological Satellites - CGMS
Community Satellite Processing
Package (CSPP) Geo Direct Broadcast
Open source software developed by
SSEC/CIMSS:
The GRB software package contains:
•
•
Software capable of processing
CCSDS packets and outputting
NetCDF-4 files containing ABI Level
1b, GLM Level 2, and all space
weather instrument L1b data.
Software to generate GeoTiff and
.png images for each ABI band.
GEOCAT- developed by NESDIS/CIMSS Geo Cloud Algorithm Team
http://cimss.ssec.wisc.edu/csppgeo/
10
CGMS-43-NOAA-WP-03
Coordination Group for Meteorological Satellites - CGMS
GOES-R Transition Summary
• GRB allows real time distribution of all Level-1b GOES-R
data products for direct read out users
• Direct Readout users need to upgrade their equipment
for GOES-R
– Significant increase in data rate
– New data format
• Documents and updates to be posted on the GOES-R
web site:
– http://www.goes-r.gov/
– http://www.goes-r.gov/users/grb.html
CGMS-43-NOAA-WP-03
Slide: 11
Coordination Group for Meteorological Satellites - CGMS
Transitioning HRIT/EMWIN
from GOES NOP to GOES-R
•
NOAA NWS Emergency Managers Weather Information Network (EMWIN) is a
priority-driven weather data broadcast service broadcast
–
–
–
•
Alerts/Watches/Warnings
Forecasts, Graphic Format Products and Imagery
Low cost ground receive stations
The NOAA NESDIS Low Rate Information Transmission (LRIT) is a collection of
reduced resolution GOES and MTSAT imagery and products
–
–
–
–
GOES Visible, Infrared and Water Vapor Imagery at 4 Km Spatial Resolution
Himawari Visible, Infrared and Water Vapor Imagery on LRIT-West
Tropical Storm Information
Copy of GOES Data Collection Service (GOES-DCS)
•
HRIT/EMWIN data service will be provided in the existing Global Specification for
HRIT/LRIT
•
The GOES-R HRIT/EMWIN service combines LRIT and EMWIN with GOES-DCS on a
single ~ 1 Meter Antenna
CGMS-43-NOAA-WP-03
Coordination Group for Meteorological Satellites - CGMS
Transitioning from LRIT and EMWIN
to HRIT/EMWIN
LRIT / EMWIN Based
on GOES NOP
HRIT/EMWIN
On GOES-R Series
Full Disk, NH, SH images
3 Hourly Full Disk; .5 hour
NH/SH; follows GOES
East/West Schedule. RSO issue
Variable but planned 3
Channels of Full Disk every
15 minutes
Modulation
LRIT BPSK
EMWIN offset QPSK
BPSK
Receiver Center Frequency LRIT 1691.0 MHz (L-Band)
EMWIN 1692.7 MHz (L-Band)
1694.1 MHz (L-Band)
Data Rate
LRIT 128 Kbps
EMWIN 19.2 Kbps
400 Kbps
Antenna Coverage
Earth Coverage to 50
Earth Coverage to 50
Imagery Data Sources
GOES NOP Imager (IR,VIS,WV)
MTSAT Imager
ABI (3 or more bands)
HBI (3 bands hourly-GOES W
EMWIN Products
Full Suite of Current Products
Combined w/ LRIT Products
GOES DCS
Copy of DCS observations
13
Copy of
observations
CGMS-43-NOAA-WP-03
Coordination Group for Meteorological Satellites - CGMS
Transitioning HRIT/EMWIN
from GOES NOP to GOES-R
• Improved data products for hemispheric retransmission
– Faster full disk images: between 15 and 30 minutes
– Warnings, Watches, Tropical Storm Information
– Copy of GOES Data Collection System (GOES DCS)
• Requires new antenna and receiver hardware
– Receiver frequency shift to 1694.1 MHz from:
• EMWIN 1692.7 MHz and LRIT 1691.0
– BPSK Modulation; EMWIN shift from Offset QPSK
– Data Rate to a combined 400 Kilobits per Second from: EMWIN: 19.2
Kbps and LRIT : 128 Kbps (combined 147.2)
CGMS-43-NOAA-WP-03
Coordination Group for Meteorological Satellites - CGMS
HRIT/EMWIN Transition Summary
• HRIT/EMWIN will provide at least 3 channels of GOES-NOP and / or
GOES-R imagery along with warnings, watches and forecast
products along with a copy of the GOES-DCS observations
• New data rate, center frequency and modulation (EMWIN Users)
• Ground receive stations are COTS utilizing a 1 – 1.2 meter antenna
• Documents and updates to be posted on the GOES-R web site:
– http://www.goes-r.gov/
– http://www.goes-r.gov/users/hrit.html
CGMS-43-NOAA-WP-03
Coordination Group for Meteorological Satellites - CGMS
Back-up Slides
CGMS-43-NOAA-WP-03
Slide: 16
Coordination Group for Meteorological Satellites - CGMS
GRB Resources and Documentation
Community Satellite Processing Package (CSPP)
GRB Prototype 0.1 Release
• Prototype release of the CSPP Geo GRB software that will allow Direct
Broadcast users to process GOES Rebroadcast (GRB) data received on their
antennas from the GOES-R satellite, after it is launched in 2016.
• The main functionality included in this release is to ingest a simulated GRB
data stream, recover Advanced Baseline Imager (ABI) Level 1 and
Geostationary Lightning Mapper (GLM) Level 2 data payloads, reconstruct
the datasets, and write output to mission-standard NetCDF files. Optionally,
quick look images can be generated from the ABI radiances.
• Later releases will add support for recovering data from the remaining
GOES-R instruments: SUVI, EXIS, MAG and SEISS.
• This software is supported on 64-bit Centos6-compatible Linux platforms.
• Publicly available for download (and free to use) at:
http://cimss.ssec.wisc.edu/csppgeo/grb_v0.1.html
CGMS-43-NOAA-WP-03
Slide: 17
Coordination Group for Meteorological Satellites - CGMS
Details of the GRB Dual Polarized Signal
• LHCP: L1b products from ABI 0.64 um band and 6 IR bands (3.9, 6.185,
7.34, 11.2, 12.3, and 13.3 um)
• RHCP: L1b products from ABI bands 0.47, 0.865, 1.378, 1.61, 2.25, 6.95,
8.5, 9.6 and 10.35um, L2+ GLM, L1b SUVI, L1b EXIS, L1b SEISS, and L1b
Magnetometer products
• Ensures load balanced utilization of the two circular polarizations,
allowing users to receive all GRB products with a dual-polarized system
(both LHCP and RHCP), and allowing users flexibility to receive GOES
Imager legacy channels with a single polarized system (LHCP only).
CGMS-43-NOAA-WP-03
Slide: 18
Coordination Group for Meteorological Satellites - CGMS
Details of the GRB Dual Polarized Signal
• Reception of the GRB data requires a fixed dish antenna
• Dual feed horns connected to 2 Low Noise Amplifiers (LNAs)
• The LNA outputs are connected to RF/IF down-converters
• RF/IF down-converters connected to DVB-S2 capable receivers
• The GRB downlink center frequency of 1686.600 MHz requires an
antenna G/T of 15.2 dB/K for worst-case locations.
• This equates to a 4.5 meter dish with a system noise temperature of
120K.
• Most CONUS locations are anticipated to have acceptable performance
with a 3.8 meter dish.
• You will need a new receive system from antenna to computer.
CGMS-43-NOAA-WP-03
Slide: 19
Coordination Group for Meteorological Satellites - CGMS
GRB Channel Content Summary
ABI L1b image Data
(compressed)
ABI
QC bits
Metadata
Space packet overhead
SUVI
Other
Info
Packets
•
•
SUVI L1b image Data
(compressed)
Metadata
Space packet overhead
GLM
Note: This is a
catalog of the
contents and not a
sequential
organization of the
stream
L2 Lightning Events/
Flashes/ Groups
(compressed)
Metadata
Space packet overhead
L1b EXIS, MAG, SEISS
science data
Included in
two
15.5 Mbps
Bandwidth
channels
•
•
•
•
For each instrument: image
data + metadata + CCSDS
Space Packet overhead
ABI has per pixel QC bits,
coded separately
ABI, SUVI, GLM compressed
GRB Info packets via CCSDS
File Delivery Protocol (CFDP)
Channel synchronization and
coding (link layer) for DVB-S2
Error correction (LDPC)
Metadata
Space packet overhead
GRB Information Packets
CFDP Overhead
Space packet overhead
Channel Synchronization
and Coding
Error Correction
CGMS-43-NOAA-WP-03
Slide: 20
Coordination Group for Meteorological Satellites - CGMS
GRB Data Characteristics
IPDU (32 Bytes)
• Each GRB data packet contains two data structures.
– IPDU header containing information extracted from the transfer
frames
– CCSDS packet containing instrument or satellite data
• Each CCSDS packet has a unique application identifier (APID):
CCSDS Packet
APID Start
(Hex)
000
100
200
300
400
500
600
700
711
CGMS-43-NOAA-WP-03
APID End(Hex)
0FF
1FF
2FF
3FF
4FF
5FF
6FF
710
7FF
Instrument
Reserved
ABI GRB
GLM GRB
EXIS GRB
SEISS GRB
SUVI GRB
Mag GRB
Info GRB
Reserved
Slide: 21
Coordination Group for Meteorological Satellites - CGMS
GRB
CCSDS
Packet
Data
Each packet is made up of four segments
:
1. Primary Header
– Specified by CCSDS
– Separate products have their own APID
2. Secondary Header
– Always present in GRB Packets
– Conformant with CCSDS Secondary Header specification
– Contains Version Number and Packet Type
– Assembler ID identifies the uplink location of GRB
Assembly generating the packet (WCDAS/RBU)
– Operational Environment identifies the Data Production
Environment within the Ground System (OE, ITE, DE)
3. GRB Data Payload (Science Data)
– Contains the actual product data
– Imagery, Atomic Blobs, or GRB Info
4. CRC
– 32-bit Cyclic Redundancy Check (CRC) to assure
packet was received correctly.
CGMS-43-NOAA-WP-03
GRB Data Packet CCSDS Structure
1
2
3
4
Bits
Field
3
Packet Protocol Version
1
Packet Type
1
Secondary Header Flag
11
APID
2
Sequence Flags
14
Packet Sequence Count
16
Packet Data Length
16
Days Since the Epoch
32
Milliseconds of the Day
3
GRB Version
5
GRB Packet Type
4
Assembler ID
4
Operational Environment
130928
GRB Data Payload
32
CRC
Slide: 22
Coordination Group for Meteorological Satellites - CGMS
GRB Data Extraction
Receive Image
Packet
Decode Primary
and Secondary
CCSDS Headers
Generic Data
Payload
Structure
Verify Packet
Checksum
Extract Data from
Generic Data
Payload
(Table 2.3.2)
Extract GRB
Payload from
CCSDS Packet
no
Last Packet in
Sequence
Received?
yes
Discard Data
from this
Sequence
All Payloads
From Seq Have
Been Received?
yes
Yes
Decompress
Data
no
No
yes
Assembler ID
Same for each
Packet in
Sequence?
Compression Flag
Set?
no
Data
Extraction
Complete
Concatenate GRB
Payloads from the
Same Sequence
Image
Payload
Structure
(Table 2.2.2)
CGMS-43-NOAA-WP-03
Finished
Slide: 23
Coordination Group for Meteorological Satellites - CGMS
HRIT/EMWIN Downlink Characteristics
• Coding – BPSK
– Convolutional rate ½ code with constraint length 7 concatenated with Reed
Solomon (255,223) with Interleave = 4
– Square Root Raised Cosine filtering using an Alpha factor of 0.3
– The resulting “Necessary Bandwidth” for this signal will be 1.205 MHz
• Modem Required: predicted C/No is in the range of 63-67 dB
• Maximum Demodulator Required is – Eb/No is 4.6 dB for a BER of 1x10-8 after decoding
• Minimum Antenna System
– At 5 degree elevation, the minimum antenna is 1.2 meter.
– At 10 degrees or more elevation the minimum size is 1.0 meter
– Using a LNA or LNB with a system noise temperature of about 200 K will
provide a G/T of 1.0 dB/K or -0.3 dB/K respectively
CGMS-43-NOAA-WP-03