How does locate frequency for PocketFinder+ work?
*8/2/17 Update - default frequency setting is 3 minutes active connection, 10 minutes rest. Constant locates, 4 minute and 20 minute intervals are also available. Airplane mode and other power options will be available based on customer feedback and final device setting calibrations.
How Does It Work?
Sometimes customers see multiple locates only 10-20 seconds apart, other times see only 1 locate every 5 minutes apart or various gaps between locates and wonder why that is. The purpose of this article is to explain how PocketFinder utilizes all three location technologies and why location frequency may very.
GPS Location Technology
GPS is typically the most accurate of the location technologies when outdoors and is the first location technology that the PocketFinder+ uses to find its location. At a location interval, the PocketFinder+ will connect with the GPS satellite network and begin to capture location data. The location accuracy or quality of this data depends on many variables such as satellite coverage, positioning of satellites, and GPS signal interference from dense materials such as metal, cement, or water. If GPS data cannot be obtained, the device will transition to Wi-Fi/Cell ID for location information. We are testing building in an accuracy threshold within 15m tp help avoid GPS drift locates. When GPS data is used, it will send and as many "good" GPS points that are captured during the 3 minutes of wireless connection and these will be displayed. When looking at history, you'll know you are looking at GPS data because you'll see many locates, typically separated by only 10-20 seconds. Gaps in this cycle are due to our system filtering locates that don't meet our quality threshold.
Wi-Fi/Cell ID Location Technology
Wi-Fi Touch location technology triangulates between Wi-Fi signals that are identified with location based on signal strength. The PocketFinder+ does not connect to Wi-Fi signals to transmit data, it sees Wi-Fi signals and their strength which is match to Google's database to approximate location. This technology is extremely helpful when a PocketFinder+ is indoors and GPS satellite signals cannot be accessed.
Cell ID Location Technology is the least accurate of the three and is a triangulation of location based on cell towers in the area and their signal strength. If a PocketFinder+ is in a backpack in a trunk of a car on the highway it will often send our servers a cell ID locate. If you don't see a locate update on the app or web interface from a device in this scenario it's because the cell ID or cell tower location data was so inaccurate we filtered that location information and did not display it.
A PocketFinder+ connecting to the Wi-Fi or Cell ID networks to get a location will only display 1 "Best" location during that active or locating 3 minutes of connectivity. If 1 "Best" or highest quality locate is displayed very quickly into the time that it's connecting for a location and then a few seconds later an even better or higher quality locate comes through we'll display that one as well.
Putting It All Together
When not moving, the PocketFinder+ will go into a "sleep" power conservation mode until it recognizes movement and wakes up. Upon waking, default setting for a PocketFinder+ is 3 minutes of active locate time followed by 10 minutes of rest. When trying to locate, the device will first try to connect with the GPS Satellite Network and will begin capturing location data. If it has accuracy data within 15m it will begin to transmit location points that are displayed on the map and will continue to locate for up to 3 minutes. These locates are typically 10-20 seconds apart. If during this period of locates a location point is considered not accurate our servers will "filter it" and not display that locate. Because it may take only a few seconds to connect to "Good" GPS location data and other times 60 seconds, the number of locates displayed may very.
If GPS location data that is accurate within 15m cannot be captured, the device will then activate the Wi-Fi/Cell ID module and begin capturing this location data. For the remaining time of the 3 minutes in active locating state, the PocketFinder+ will capture and transmit location data. Our servers will display only the highest quality or "Best" locate available. This is typically 1 locate. Sometimes a locate will come through early in the connection period that is considered "Best" and it will be displayed. If an even higher quality locate comes through a few seconds later we will display that locate.
With the default 3 minute wireless connections, if your PocketFinder+ can connect to the GPS Satellite Network, you will see multiple locates 10-20 seconds apart every 10 minutes. If it can only connect to Wi-Fi or Cell ID location services, you will see 1 locate every approx. 10 minutes. Smaller interval settings including constant locates are available.