The Global Positioning System: A Shared National Asset (1995)
Chapter: Inmarsat
and is compiling information on maritime DGPS broadcasts worldwide. Currently Sweden, Finland, The Netherlands, Denmark, Iceland, and Germany have complete or nearly complete coastal coverage. Several other countries have prototype or demonstration services including Australia, Canada, China, Norway, and Poland. India and South Africa are planning maritime DGPS services.
International Participation in the FAA's WAAS
In order to eventually develop the WAAS into a Global Navigation Satellite System (GNSS) that is useful to aircraft anywhere in the world, the FAA is encouraging other nations to participate in the program at any level they feel comfortable with.56 Nations involved at the lowest level will simply utilize the GPS-like WAAS signals without any contribution to the system in the form of ground based wide-area reference stations. Participation at a higher level would involve the installation of wide-area reference stations and possibly wide-area master stations within the sovereign territory of a nation. Even higher levels of involvement are possible if a nation is willing to provide a geostationary satellite for the space segment of the system. Several countries have expressed an interest in WAAS participation, including Canada, Australia, New Zealand, and Japan.57
Inmarsat
Inmarsat (the International Maritime Satellite Organization), a not-for-profit international organization that provides global mobile satellite services to the maritime, land- mobile, and aviation markets, has firm plans to augment GPS by placing a navigation payload on board its third generation geostationary communications satellites. Plans call for this payload to broadcast GPS and GLONASS integrity information, ranging information, and wide-area differential corrections on a "GPS-like" L1 signal centered at 1575.42 MHz. These satellites and their navigation payloads may form the nucleus of the WAAS space segment if the winning team of contractors chooses to use them. Future Inmarsat plans include the possible development of a fully civil GNSS based on light satellite (lightsat) navigation payloads placed in intermediate circular orbits and geostationary orbits.58
