Concurrent GPS&GLONASS dual satellites helps accuracy. The device receives more satellites signals to improve accuracy and reliability, especially when poor weather or at critical landforms. When Linux and Android systems require geography locators, GR-A013 is easy to install for the device driver is already built-in. Raspberry PI users are welcomed to use the device. Built-in magnet for any metal attachment. It is an useful navigation device for land, aviation and marine. 4-satellites constitutes a gps position. 2-concurrent-constellations gps receiver, which has normally connected more than 10 satellites, is the most optimized for accuracy and reliability.
GPS receiver connecting more than 2 constellations doesnt improve accuracy.