we are developing a tracking software and we are the stage where we test the reliability of our location stigma on the following webmaps

Google Nokia Open street

We observe that our location appears accurate on Google maps, however when switched to Nokia or Openstreet there is a discrepancy of around 40-50 metres from our actual location. Most importantly our GPS position accuracy is around 2m.

Could it be inaccuracy of map calibration or any similar problems known by anyone?

We are developing a tracking software and we are the stage where we test the reliability of our location stigma on the following web-maps

• Google Map
• Nokia HERE
• Open Street Map (OSM)

We observe that our location appears accurate on Google maps, however when switched to Nokia or Openstreet there is a discrepancy of around 40-50 metres from our actual location. Most importantly our GPS position accuracy is around 2m.

Could it be inaccuracy of map calibration or any similar problems known by anyone?