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en:help:1.4:tracker [2014/06/09 15:32] – alpinequesten:help:1.4:tracker [2015/09/02 11:51] – [Common issues with the Location Tracker] alpinequest
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 <sub>[[en:help|Online Help]] > [[en:help:1.4|AlpineQuest 1.4]]</sub> <sub>[[en:help|Online Help]] > [[en:help:1.4|AlpineQuest 1.4]]</sub>
-===== The Location Tracker =====+====== The Location Tracker ======
  
 The AlpineQuest GPS Location Tracker is a background service that records all your locations and creates a track of your hikes. The AlpineQuest GPS Location Tracker is a background service that records all your locations and creates a track of your hikes.
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   * The "**''Update frequency''**" {{:icon_02.png?nolink}} allows you to choose how fast the locations have to be recorded. For runners, a precise tracking is recommend, whereas hikers should prefer a medium one, since a fast tracking will use more battery.   * The "**''Update frequency''**" {{:icon_02.png?nolink}} allows you to choose how fast the locations have to be recorded. For runners, a precise tracking is recommend, whereas hikers should prefer a medium one, since a fast tracking will use more battery.
  
-{{:icon_help.png?nolink}} Some location sources can be disabled from the device settings. Click on the "**''Location sources''**" {{:icon_04.png?nolink}} button to access these settings easily.+{{:icon_help.png?nolink}} Some location sources can be disabled from the device settings. Click on the "**''Location sources''**" {{:icon_03.png?nolink}} button to access these settings easily.
  
  
 ==== Locations filtering ==== ==== Locations filtering ====
  
-{{ :en:help:1.4:tracker:tracker-settings-2.jpg?nolink}}+Location filters allow you to reduce the amount of recorded locations in order to reduce the battery usage and to increase the tracking accuracy (by reducing GPS inaccuracy errors).
  
-Location filters allow you to reduce the amount of recorded locations to reduce battery usage and to increase the tracking accuracy.+{{ :en:help:1.4:tracker:tracker-settings-2.jpg?nolink}}
  
 {{:icon_help.png?nolink}} The "''**accuracy filter**''" will avoid recording erroneous locations while temporary loss of accuracies, while the "''**distance filter**''" will avoid recording useless similar locations while not moving. {{:icon_help.png?nolink}} The "''**accuracy filter**''" will avoid recording erroneous locations while temporary loss of accuracies, while the "''**distance filter**''" will avoid recording useless similar locations while not moving.
  
 When a new location is computed by the GPS based on the update frequency, the application will: When a new location is computed by the GPS based on the update frequency, the application will:
-  * Check that the location accuracy is better or equals to the "''**accuracy filter**''" setting {{:icon_08.png?nolink}}; +  * Check that the location accuracy is better or equals to the "''**accuracy filter**''" setting {{:icon_05.png?nolink}}; 
-  * Check that the distance from the previous location is greater or equals to the "''**distance filter**''" setting {{:icon_07.png?nolink}}, or that the location accuracy is better than the previous one.+  * Check that the distance from the previous location is greater or equals to the "''**distance filter**''" setting {{:icon_04.png?nolink}}, or that the location accuracy is better than the previous one.
  
 For instance, when using an update frequency of 5 seconds, a distance filter of 3 meters and an accuracy filter of +/-256 meters, all recorded locations: For instance, when using an update frequency of 5 seconds, a distance filter of 3 meters and an accuracy filter of +/-256 meters, all recorded locations:
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 ==== Barometric elevations ==== ==== Barometric elevations ====
  
-If your device has a built-in pressure sensor, you can activate the "**''barometric elevations''**" {{:icon_08.png?nolink}} feature which will compute elevation values based on the air pressure, in addition to the common GPS elevations. These barometric altitudes are much more accurate and reactive, and can be computed precisely even if the GPS signal is very poor.+If your device has a built-in pressure sensor, you can activate the "**''barometric elevations''**" {{:icon_07.png?nolink}} feature which will compute elevation values based on the air pressure, in addition to the common GPS elevations. These barometric altitudes are much more accurate and reactive, and can be computed precisely even if the GPS signal is very poor.
  
 {{:icon_help.png?nolink}} The barometric data is auto-calibrated by AlpineQuest using GPS locations. {{:icon_help.png?nolink}} The barometric data is auto-calibrated by AlpineQuest using GPS locations.
 +
 +
 +===== Common issues with the Location Tracker =====
 +
 +A common issue when recording a track is to lost the GPS location, leading to a missing part in the track (seen as a straight line longer than usual). Usually, it happens because the device doesn't have a good enough access to the sky, for example when the device is placed in a pocket or in a bag. The GPS signal emitted by GPS satellites is weak and gets easily lost when going through any material. If you have the "**''lost of signal warn''**" {{:icon_06.png?nolink}} setting activated, the application will play a song when it looses the GPS signal.
 +
 +Also, tracking a path requires frequent GPS location updates and some devices (mainly old or low-cost ones, but not always) doesn't support the GPS being turned on for long hours. Common symptoms in this case can be:
 +
 +  * The device becomes more hot than usual;
 +  * The GPS doesn't report anymore satellites for some time, the location fix is lost, leading to a missing track part;
 +  * The Location Tracker is simply closed by the system, the tracking is stopped.
 +
 +If you encounter one of these symptoms, you can try to:
 +
 +  * Reduce the tracking frequency, a location per 10 seconds is a recommended setting for hours long tracks;
 +  * Use an economy tracking frequency (starting at 1 location / 20 seconds), in which the GPS is completely turned off between update. Be sure to leave your device in view of the sky so the GPS can quickly retrieve a location for each update;
 +  * Turn off the recording of barometric elevations to leave the pressure sensor turned off (this one can also be the source of issues when continuously used for long time).
  
  
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   * [[en:help:1.4:landmarks:format-gpx#how_to_export_tracks_in_gpx_format|How to export tracks in GPX format ?]]   * [[en:help:1.4:landmarks:format-gpx#how_to_export_tracks_in_gpx_format|How to export tracks in GPX format ?]]
   * [[en:help:1.4:landmarks:format-kml|How to export tracks in KML format ?]]   * [[en:help:1.4:landmarks:format-kml|How to export tracks in KML format ?]]
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