Paljon on puhetta siitä, että GPS:ssä on häiriöitä, https://gpsjam.org . GPS on tapa toimittaa täsmäase kohteeseensa, paljon hyrräkompassia halvempi ja täsmällisempi.
On kuitenkin muitakin satelliittipaikantamisen keinoja kuin Yhdysvaltain GPS: kiinalainen Beidou, Euroopan unionin Galileo ja venäläinen Glonass. Satellittipaikannuspalveluita on paljon, koska satelliittipaikannus on tai voi olla myös suurvalta-ase.
SBAS (Satellite-Based Augmentation System) around the world provide free, real-time sub-meter corrections for high-performance GNSS receivers. SBAS is a fantastic, free public service that GIS professionals around the world can use to make their GNSS receivers more accurate, and therefore make their GIS databases more accurate.
The beauty of SBAS is that each covers an entire continent. For example, the WAAS SBAS in North America covers Canada, the United States, Central America as well as the northern portion of South America. That means your GNSS receiver can receive sub-meter corrections anywhere on the continent, without requiring internet connectivity.
All SBAS are operated by government agencies and designed primarily for aviation navigation. This means that SBAS are extremely reliable. They never go “out of service” for any reason. Following is a list of current SBAS around the world:
WAAS (Wide Area Augmentation System) – Canada, United States, Central America, northern region of South America.
EGNOS (European Geostationary Navigation Overlay Service) – Western/Eastern Europe and Northern Africa.
MSAS (Multi-functional Satellite Augmentation System) – Japan.
GAGAN (GPS Aided Geo Augmented Navigation) – India and parts of surrounding countries.
SDCM (“System for Differential Correction and Monitoring”) – Russia (in deployment)
https://eos-gnss.com/knowledge-base/art ... tions-free