Petfon may fail to locate due to the following reasons::

1, Controller/Tracker disconnected

--------Petfon would not be able to position when either controller or tracker is disconnected. Please kindly check their connection status through the following page:

 

2,Harsh using environment

-------Petfon's performance could not be guaranteed in woods,forest or tunnels. In order to explain it more clearly, please kindly allow us introduce the working mechanism for Petfon.

Petfon is positioned directly by GPS, while GPS signal could be blocked by obstructions,  the obstacles could result into a weak positioning or even positioning failure. 
In our case, the positioning of our tracker depends highly on the obstacles between GPS satellite and the tracker, if your pets run into some areas with heavy shelters above,GPS would not be able to position it accordingly.

3,GPS not available

---------There are very few areas that GPS is not covered, no GPS devices could work in these types of areas or only works occasionally.

4,Petfon GPS module damaged or defected

--------Petfon's GPS module could be damaged by violent knocks, dog bites, long time exposure to the rain or sinking in the water

GPS accuracy

We strongly advise you to visit the Official GPS Website, that clearly explains how the GPS technology works, not only for PETFON but for any other device that features GPS technology (like other GPS dog trackers and smartphones).

Basically, the Official GPS Website states that GPS accuracy depends on the amount of obstacles between the GPS satellites and the device itself. In sum, here are some key points stated in the above-mentioned website that will tell you the GPS accuracy you should expect for different use cases (this information influences the performance of regular Map tracking, Radar, History and GPS fences):

Good GPS accuracy: open outdoor areas (beaches, national parks or urban squares).Bad GPS accuracy: very dense areas (impenetrable forests or very crowded urban environments, with a high amount of obstacles); cloudy weather; the indoor use case is not advisable.

 

https://www.gps.gov/systems/gps/performance/accuracy/