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Becoming a GEONETCast User
By Sally Wannop, User Relations Manager, EUMETSAT; Linda Moodie, GEONETCast Point of Contact; Christopher O’Connors, Direct Services Division Chief, NOAA; and Jiashen Zhang, China Meteorological Administration
GEONETCast is a global, near-real-time, environmental data dissemination system in support of the Global Earth Observation System of Systems (GEOSS). It uses commercial telecommunication satellites to broadcast data and products to a wide User community. GEONETCast is particularly useful for distributing operational or project data where a large number of users can benefit and/or where Internet access has low bandwidth or is non-existent.
The goal of the system is to enable the enhanced dissemination, application, and exploitation of environmental data and products for the diverse societal benefits defined by the Group on Earth Observations (GEO), including agriculture, energy, health, climate, weather, disaster mitigation, biodiversity, water resources, and ecosystems.
The system consists of three regional broadcasts: EUMETCast (operated by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), covering Europe, Africa, and parts of Asia and the Americas), FENGYUNCast (operated by the China Meteorological Administration, covering Asia and parts of the Pacific), and GEONETCast Americas (operated by the US National Oceanic and Atmospheric Administration (NOAA), covering North, Central, and South America and the Caribbean. The coverage of GEONETCast is illustrated in Figure 1.
Fig. 1 GEONETCast footprints
Access to GEONETCast reception is open to any User within the footprint of one or more of the GEONETCast beams. Whilst standard Digital Video Broadcasting (DVB-S) technologies are generic to all three GEONETCast systems, there are some subtle differences between the systems which influence the reception station set-up. Likewise, each GEONETCast Network Centre (GNC), responsible for the operation of its own regional broadcast, applies a slightly different approach to User registration and data access.
To ease User access, each Network Centre provides comprehensive information about its system and registration process via its web site. A single catalogue listing the contents of data streams, the GEONETCast Product Navigator, is available and is disseminated via the GEONETCast broadcasts.
The GEONETCast system
The GEONETCast system has been designed to utilise off-the-shelf technology which support cost-effective and affordable data delivery to a wide User audience ranging from the man in the street to research institutes and government agencies. Features of the GEONETCast system include:
- Use of off-the-shelf, commercially available, DVB-S reception equipment
- Highly scalable system architecture
- One-stop-shop delivery mechanism allows Users to receive many data streams via one reception station
- An installed User base of over 3,000 User stations worldwide
- Handling of any file format, allowing the dissemination of a broad range of products
Data files generated by GEONETCast data providers are transferred to the GEONETCast uplink facility. These files are encoded and transmitted to geostationary communications satellites for broadcast to User receiving stations. Files are sent over the system organized into a series of sub-channels, similar to how a satellite television broadcast is organized into selectable sub-channels by the broadcaster. These sub-channels can be selected or de-selected, allowing users to download all or any relevant portion of the GEONETCast broadcast that they need.
Once the channel is selected, each receiving station decodes the signal and recreates the data/products, according to a defined directory and file name structure.
Data streams available to Users typically include:
- Space-based observations from the Meteosat, Metop, NOAA, Jason-2, GOES, MT-SAT, FY2 and FY-3A satellites; at their most frequent, these data are delivered to Users within five minutes of processing
- MODIS level 1 and 2 products covering selective geographical regions
- Land application products covering Europe, Africa and South America
- Marine meteorological and ocean surface products covering the Atlantic, Mediterranean Sea and Yellow Sea
- Atmospheric chemistry products
Products vary between regional services. For more detailed information on product availability in your area, please refer to the regional provider’s web site to explore its product navigator.
Reception set-up and User registration
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Fig. 2 Typical GEONETCast Reception Station Components |
A typical GEONETCast reception station comprises a standard personal computer (PC) with DVB-S card inserted and a satellite off-set antenna fitted with a digital universal V/H LNB. All components of the reception station are commercially available. The hardware costs for a single PC station reception can be as little as €1,500 ($2000). In addition, a Client Software Package is required for handling the incoming DVB-S and storing it as data files. This package is available directly from regional GEONETCast Network Centres.
Registration typically involves the completion of an online registration form. For further information on the User registration process or on becoming a GEONETCast Data Provider, please contact your local GNC User Helpdesk:
EUMETCast: EUMETSAT User Helpdesk
email: ops@eumetsat.int
Web: http://www.eumetcast.com
FENGYUNCast: CMA, Mr. J. Zhang
email: zhangjs@cma.gov.cn
Web: http://www.nsmc.cma.gov.cn
GEONETCast-Americas: NOAA
email: paul.seymour@noaa.gov
Web: http://www.geonetcastamericas.noaa.gov/
Further information on GEONETCast: http://www.geonetcast.org
Discovering GEONETCast data
The GEONETCast Product Navigator is the data discovery component of the GEONETCast system. By searching with the GEONETCast Product Navigator, information can be found on products disseminated via GEONETCast. Such information includes product descriptions, file formats, dissemination frequency and links to other online resources such as product guides. Users can search using keywords and via themes, such as Societal Benefit Areas.
Fig. 3 GEONETCast Product Navigator
The Product Navigator is disseminated via the GEONETCast broadcasts and versions of the Navigator are available via the GNC Web sites, e.g.: http://navigator.eumetsat.int and www.geonetcastamericas.noaa.gov/product-productlisting.html.
Channels for hazard alerts and for training
In 2008, GEONETCast demonstrated initial proofs of concept for a Hazard Alert Channel, intended to relay regional environmental warnings and alerts in priority broadcasts to users. Discussions are also underway to transmit data and products for disaster response.
Also in 2008, GEONETCast demonstrated proofs of concept for a Training Channel dedicated to products and programming designed to train new users in the application and production of Earth observation products and in the use of tools for accessing Earth observation information. GEONETCast is developing a service strategy on how to operationally deploy the Training Channel, including determining user requirements and how file selection and broadcasts will be optimized to best serve user needs.
Conclusion
GEONETCast is an operational and effective, low-cost, satellite-based, dissemination system for Earth observation data. GEONETCast broadcasts environmental information to Africa, Asia, Europe, the Americas, and parts of the Pacific. The system’s user base is growing and diversifying. Although challenges exist, GEONETCast is meeting them and making measured progress in expanding the user base and increasing the value of the system worldwide.
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