When indoors, GPS doesn't work because it needs line of sight to satellites. In order to track someone indoors, AngelSense developed different features to overcome general GPS limitations: Track the entry point for an indoor location Check the log from their most recent transit to figure out their entrance point for an indoor location. Transits...GO »
GPS Signal Troubleshooting
Poor GPS (gray circle)
When your device has poor GPS signal it will show a gray circle to indicate this. The gray circle is not the size of the radius that you have set for this location, just an indication that the device does not have sufficient GPS signal at this time.
GPS technology has limitations, regardless of AngelSense, that we essentially try to make the best of using our analytics. GPS reception indoors is poor due to not having line of sight with satellites, along with GPS limitations in general. Once the device is able to gain GPS signal upon leaving the indoor location it will resume sending the GPS location.
Tracking during No GPS
Indoors GPS typically has no reception. This normally does not impact the app, since AngelSense smart analytics “understand” the device has not left that place and it is likely that it is still indoors in that place.
In standard GPS devices, the lack of GPS reception indoors is a major issue since there are no analytics and a caregiver is unable to track the device in such a case. AngelSense on the other hand, shows you the exact route to the indoors place and is smart enough to determine the device is still there.
The AngelSense device stores the GPS readings in its memory and once the cellular connection is re-established, it will transmit the entire GPS recording it stored. This ensures that even in cases when the cellular connectivity is lost all the data for your device’s schedule is saved.
GPS can be affected by poor signal strength from being indoors or being pressed up against something metal. Bad satellite signals and signal interference happen when something gets in the line of sight between your GPS device and the satellite network.
Tall buildings, dense foliage, mountains, and even reflective objects can cause such a problem. For example, in areas of skyscrapers there is a phenomenon called “reflection”, where the signal from satellites reflects through the buildings and may cause the location to be off.
We cannot eliminate the GPS errors, but we can indicate to you that accuracy is limited. Our analytics will also filter out many of the false exits from indoors locations due to GPS reception issues.
We have evaluated many devices, picked the best one and on top of it built sophisticated analytics that build the daily schedule and create reliable alerts.
Still, in downtown areas the solution will have accuracy limitations. What this means is that when downtown, the GPS may have more significant errors. It is the limitations of the core GPS technology, regardless of AngelSense.
There can be two reasons for missing a transit.
- During calls, the device cannot transmit GPS data and thus if you are on a call (1-Way Voice or 2-Way Voice ) with the device throughout the entire transit, the system will miss the transit.
- GPS reception issues during the transit, e.g. since the child is far from a window or device is blocked by a metal object.
Typically the device would have GPS signal inside a vehicle and it is rare for it not to. For a better idea, knowing where the device is located within the vehicle may help to understand what may be causing the loss of GPS signal. For example, if it is in the middle of the vehicle as compared to closer to a window. Or worn on the back as opposed to on the front or side pockets. You may try wearing the device in a different location to see if this helps.