Eero Nevalainen has studied the quality of Finnish GPS augmentation systems in his thesis, "Evaluation of Global Positioning System Augmentation Options for Finland", carried out for Indagon and the Finnish Maritime Administration (now part of the Finnish Transport Agency). In his thesis Nevalainen has analyzed the accuracy and availability of Finland's maritime Differential GPS (DGPS) and the new European Geostationary Navigation Overlay System (EGNOS) system in the area of Finland. The study uncovers deficiencies in the accuracy of both the maritime DGPS and the EGNOS system and notes that the availability of the EGNOS system is very limited in Finland.

In Finland, GPS augmentation systems are used among other things in the guidance and safety equipment of land and sea transportation. The Finnish maritime DGPS system is well over 10 years old, and its equipment is now practically obsolete. The new European EGNOS system has been considered as a replacement for the old DGPS system, but its satellites are located below 22◦ elevation in Southern Finland. At low elevations the availability of the EGNOS signal becomes too poor for inland applications and maritime users may be affected by signal reflections from the sea surface.

GPS augmentation systems will soon again be needed, because the Sun's 11-year cycle has progressed to the early phases of the next solar storm. According to the International Space Environment Service (ISES) forecast the Sun's activity will quickly rise to its maximum in 2013 and wane slowly after the peak. The stormy space weather will hamper GPS positioning both by causing malfunctions in the satellites and by distorting the GPS signal as it travels through the atmosphere. Both the EU and the United States are attempting to address these challenges with the Galileo and GPS modernization programs, but due to delays neither solution will be available before the next solar maximum.

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http://www.sal.hut.fi/Publications/pdf-files/TNEV10.pdf

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