If you would like to improve your data, Amazon offers a Garmin GLO portable GPS and GLONASS receiver.  This device connects to your cell phone via a bluetooth port.  There are a number of accessories that can be purchased for it as well.

What is GLONASS?

GLONASS stands for Globalnaya Navigazionnaya Sputnikovaya Sistema which is Russian for “Global Navigation Satellite System”.  This is Russia’s version of GPS.  There are many differences between GPS and GLONASS such as the number of satellites (24 – GLONASS &  31 – GPS), orbital height (21150 km – GLONASS & 19130 km GPS), orbital plane inclination (64.8 degree – GLONASS & 55 degree – GPS) and frequency.  The idea is that both of these used together increases the accuracy of the data.