HOW GPS WORKS 101
GPS works by the phone’s GPS antenna receiving signals from orbiting navigation satellites. The more satellites that the phone’s antenna receives signal from, the more accurate the location will be. If the phone is not able to receive signal from at least 3 satellites, it will not be able to calculate a location at all.
WHEN WON’T GPS WORK?
There are a number of reasons why GPS tracking might not work from time to time. How often these occur will depend on the environment in which the phone is primarily used as well as other factors beyond anyone’s control:
- USER OVERRIDE – the phone’s user may turn “location services” off (the software that runs the GPS receiver on the phone) or they may turn the GPS receiver off (if this option exists in the phone’s menu). This may be a deliberate action for privacy reasons or to reduce the drain on battery and phone resources that is caused by having location services enabled.
- POWER SAVING – most phones incorporate power saving features. Some of these features are automatic and enabled by default while others can be configured by the user. A common power saving feature allows the device to turn off phone services and features in order to conserve remaining battery power. Since the GPS receiver consumes a considerable amount of power and other phone resources, it is often one of the first casualties of power saving.
- NO LINE OF SIGHT – As the GPS antenna requires signal from at least 3 satellites, any obstacles between the phone and the sky, for example walls, ceilings, trees, can prevent the phone from being able to receive signals and it will therefore be unable to calculate a location.
- POOR WEATHER CONDITIONS – weather can impact reception of GPS satellite signals. Heavy cloud cover, for instance, can block the signals entirely, while electrical and other weather activity can cause interference that renders the signals unusable by the target phone.
- LOW RESOURCES – obviously the phone must be turned on for GPS tracking to work, but even if turned on, if the battery, processor, memory or other phone resources are below a certain threshhold, the GPS receiver may not function. This might be caused by the user having too many applications running in the background or due to poor management of the devices resources by 3rd party software.
- 3RD PARTY SOFTWARE – apps are available from the Play Store and elsewhere that can lock the GPS receiver, thereby preventing it from being used by other software on the phone (perhaps without the approval of the user)