Common Alerting Protocol (CAP) Implementation Workshop Geneva, Switzerland, 6-7 April 2011 The GEONETCast Alert Channel and CAP over GTS Simon Elliott EUMETSAT [email protected]
Mar 27, 2015
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
The GEONETCast Alert Channel and CAP over GTS
Simon Elliott
EUMETSAT
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Distribution of satellite products
• EUMETSAT operates meteorological satellites• Satellite data are processed to derive a range of
products (images, radiance data, wind information, soil moisture, fire detection, etc.)
• Products are produced operationally in near real time in a variety of formats
BUFR - GRIB - JPEG - ASCII - netCDF - HDF
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Distribution mechanisms
Several mechanisms are used to distribute satellite products• EUMETCast/GEONETCast
– Satellite DVB-S multi-cast service
– Easy access, many users, almost global coverage
• Global Telecommunication System, GTS– Global network connecting NMHSs
– Limited access, highly controlled, well established
• Website access• Archive access
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Volcanic Ash Detection
• Infrared image data from METEOSAT are processed to detect the presence of volcanic ash
• Products could be:– GRIB or BUFR encoded for NWP community
– Graphically represented (e.g. JPEG) for Volcanic Ash Advisory Centre (VAAC) or internet presentation
– Described with a plain text bulletin or in XML
• CAP can be used to encapsulate these formats
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Volcanic Ash on EUMETCast
CAP message
Style sheet referenceGraphics
Text
CAP message contains standard information supplemented by hyperlinks to associated information
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Sample web page containing a volcanic ash CAP message
Display is style sheet dependent
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
GEONETCast Overview
EUMETCastNetworkCentre
FENGYUNCastNetworkCentre
GEONETCastAmericasNetworkCentre
EUMETCastUsers
EUMETCastData
Providers
FENGYUNCastUsers
FENGYUNCastData
Providers
GEONETCastAmericas
DataProviders
GEONETCastAmericas
Users
Data exchange
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
GEONETCast Coverage
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
GEONETCast Alert Channel• GEONETCast Americas has an alert channel• EUMETCast is EUMETSAT’s component of
GEONETCast• EUMETCast currently has a virtual alert channel (part
of product channel)• In next couple of months dedicated EUMETCast alert
channel will be enabled• EUMETSAT uses CAP for some of its own products.
The MSG Fire Detection and Volcanic Ash products are created using CAP
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Channel Based Dissemination• Each product/product category is assigned to a
dedicated multicast channel on GEONETCast such as RA-VI BMD,
• Training Channel, Info Channel, Data Channel 1-4 etc. … and “Alert Channel”
• Each channel uses either a dedicated or shared bandwidth for dissemination
• Priorities are assigned depending on delivery needs
• User groups can be assigned to each channel (access control supported)
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Dedicated Alert Channel
• Dedicated bandwidth
• Channel is kept free of any other data then alerts
• Channel is setup for high priority and immediate dissemination
• Data exchange to the partner GNCs
• NRT availability of CAP alerts simultaneously on the entire footprint
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
GEONETCast Alert Channel
GEONETCastNetwork Centre
PartnerNetworkCentre
GEONETCastUsers
ReceptionStationALERT
Providere.g. GISC,
DCPC, NC, Others
Data exchange
CAP Alerts
InternetUsers
Normal data
High priority NRT-Dissemination ofCAP Alert Messages
Portal(Product Navigator)
Multicast NRTDissemination
-Recognises incoming CAP alert file-Raises alert
-CAP Alert stored in WEB portal for Internet retrievals - can discover and
subscribe to CAP alerts
-High priority processing and NRT dissemination on dedicated channel
-On reception of a CAP alert the GNC decodes the alert to distinguish if the alert is for global exchange or regional
GNCReference Reception
Station
- feedback of CAP alert reception for SLA monitoring
- regular transmission of empty alerts in order to check the status of the channel
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
The Global Telecommunication System
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Volcanic Ash on GTS
CAP message
Style sheet reference
GTS wrapper
CAP message
Style sheet reference
CAP message
Style sheet reference
EUMETSAT NWP Centre
CAP message in XML is wrapped with routing information for the GTS. The wrapper is removed after transfer to the destination to restore the original message.
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Wrapping of CAP for GTS<?xml version = "1.0" encoding = "UTF-8"?><?xml-stylesheet type="text/xsl“ href="cap_alert_eum.xsl"?><alert xmlns = "urn:oasis:names:tc:emergency:cap:1.1"> <identifier>EUM.MET09.VASH.1</identifier>... </info></alert>
<SOH>\r\n\rnnn\r\r\n[ABH]\r\r\n<?xml version = "1.0" encoding = "UTF-8"?><?xml-stylesheet type="text/xsl“ href="cap_alert_eum.xsl"?><alert xmlns = "urn:oasis:names:tc:emergency:cap:1.1"> <identifier>EUM.MET09.VASH.1</identifier>... </info></alert>\r\r\n<ETX>
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Abbreviated Bulletin Headers for CAP
ABHs have the form
For volcanic ash data in CAP, this could be:T1 = X [Common Alerting Protocol (CAP)]T2 = V [Volcanic ash clouds (SIGMET)] or O [Other]A1A2 = NT [North Atlantic area, case dependent]ii = 01 [Essential data as per WMO Resn. 40]CCCC = EUMG [EUMETSAT/MSG]YYGGgg = 091345 [date & time, case dependent]
Several choices of T1T2 have been considered, including WV, FX, WX, XW, XO and WO. It is important that the data are not confused for an existing product. The most recent suggestion, after consultation with, among others, ICAO is T 1T2 = XO.
Common Alerting Protocol (CAP) Implementation WorkshopGeneva, Switzerland, 6-7 April 2011
Conclusion
• The intrinsic standardisation of CAP ensures syntactic and semantic interoperability of the data
• Dissemination of volcanic ash products using CAP on the GTS and via EUMETCast/GEONETCast allows one product to meet the requirements of different groups of users
• CAP messages can supply the GTS community with information which can be understood and used in a variety of applications and disciplines