GPS GNSS Accuracy

Please read this page, before.

Who more accuracy U-blox 6 generation (GPS) or U-blox 8 generation (GNSS)?

NAVSTAR GPS accuracy - about 2-4* m Global Glonass accuracy - 3-6** m Global Galileo - accuracy unknown (first services should be launched at the turn of 2014 and 2015. Full completion of the Galileo system is expected by 2019) EU Asia ., BeiDou, QZSS First of all where are you from? If you are from Russian or neighbors country than yours better choice will be U-blox 8 generation (GNSS) if not choose U-blox 6 generation (GPS).

Why so. According to this document, accuracy of GLONASS outside of Russia is less than 9 meters.