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manual:user_guide:tools:altitude
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manual:user_guide:tools:altitude [2015/04/21 12:48] – mstupkamanual:user_guide:tools:altitude [2016/10/21 16:04] – [Pressure sensor] mstupka
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   * **settings of pressure sensor**   * **settings of pressure sensor**
 ===== Settings ===== ===== Settings =====
-{{ :manual:user_guide:tools:altmanager.png?nolink|}}+{{ :manual:user_guide:tools:altmanager.png }}
 ==== Altitude offset ==== ==== Altitude offset ====
  
-  * **Use altitude offset** - switches on the definition of offset between real and GPS altitude. More in the **Offset tab**.+  * **Use altitude offset** - switches on the definition of offset between real and GPS altitude. More in the **[[manual:user_guide:tools:altitude#offset|Offset tab]]**.
 ==== Pressure sensor ==== ==== Pressure sensor ====
  
-  * **Use pressure sensor** - switches on measuring precise altitude by the device built-in barometric pressure sensor. More in the **Pressure tab**.+  * **Use pressure sensor** - switches on measuring precise altitude by the device built-in barometric pressure sensor. More in the **[[manual:user_guide:tools:altitude#pressure_sensor1|Pressure tab]]**.
 ====  Elevation data ==== ====  Elevation data ====
-  * **Optimize GPS altitude** - uses [[http://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission|offline elevation data (HGT)]] to optimize GPS altitude values. Computed altitude has similar accuracy to an average GPS but does not contain serious errors GPS units usually make. HGT files are downloaded usually together with Locus Maps or can be additionally downloaded by a "fill altitude" command [[manual:user_guide:tracks:management#track_detail_screen|editing tracks]].+  * **Optimize GPS altitude** - uses [[http://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission|offline elevation data (HGT)]] to optimize GPS altitude values. Computed altitude has similar accuracy to an average GPS but does not contain serious errors GPS units usually make. HGT files are downloaded usually together with LoMaps or can be additionally downloaded by a "fill altitude" command [[manual:user_guide:tracks:management#track_detail_screen|editing tracks]].
 <WRAP round alert > <WRAP round alert >
 **Warning for pilots**: this method is not recommended for activities when you are **not moving on the ground** - displayed altitude values are influenced by the ground altitude measuring and calculation **Warning for pilots**: this method is not recommended for activities when you are **not moving on the ground** - displayed altitude values are influenced by the ground altitude measuring and calculation
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 ===== Offset ===== ===== Offset =====
  
-{{ :manual:user_guide:tools:altmanager2.png?nolink|}}Altitude calculated by internal GPS unit is related to a different method of referencing the Earth surface than that used in maps. The difference between them is called **Geoid height** which is distance between [[http://en.wikipedia.org/wiki/Geoid|Geoid]] and [[http://en.wikipedia.org/wiki/Reference_ellipsoid|reference elipsoid]].+{{ :manual:user_guide:tools:altmanager2.png }} 
 +Altitude calculated by internal or external (Bluetooth) GPS unit is related to a different method of referencing the Earth surface than that used in maps. The difference between them is called **Geoid height** which is distance between [[http://en.wikipedia.org/wiki/Geoid|Geoid]] and [[http://en.wikipedia.org/wiki/Reference_ellipsoid|reference elipsoid]].
  
 Locus Map can define this offset by three methods: Locus Map can define this offset by three methods:
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   * **Altitude NMEA correction** - mobile device communicates with GPS unit over a special messages called NMEA. These messages contain values of Geoid height that Locus Map can read and apply them to correct this offset.<wrap alert>Some devices report incorrect values so this method is unreliable.</wrap>   * **Altitude NMEA correction** - mobile device communicates with GPS unit over a special messages called NMEA. These messages contain values of Geoid height that Locus Map can read and apply them to correct this offset.<wrap alert>Some devices report incorrect values so this method is unreliable.</wrap>
 ===== Pressure Sensor ===== ===== Pressure Sensor =====
-{{ :manual:user_guide:tools:altmanager3.png?nolink|}}Some devices are equipped with barometric pressure sensor. Barometric sensors measure atmospheric pressure very precisely which can be used for calculating relative altitude changes. I.e. if you know certain pressure at certain altitude you can calculate altitude changes between known and current position.+{{ :manual:user_guide:tools:altmanager3.png }} 
 +Some devices are equipped with barometric pressure sensor. Barometric sensors measure atmospheric pressure very precisely which can be used for calculating relative altitude changes. I.e. if you know certain pressure at certain altitude you can calculate altitude changes between known and current position.
  
 The pressure sensor must be calibrated to a known altitude value so that it can be used for real altitude value calculations. Locus Map offers several methods: The pressure sensor must be calibrated to a known altitude value so that it can be used for real altitude value calculations. Locus Map offers several methods:
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   * **Altitude** - uses some other source of ground altitude - external maps, measuring, tourist guide posts, etc. as the reference. Locus Map then calibrates the pressure sensor according to this value.   * **Altitude** - uses some other source of ground altitude - external maps, measuring, tourist guide posts, etc. as the reference. Locus Map then calibrates the pressure sensor according to this value.
 <WRAP  round important>Some devices like e.g. Samsung Galaxy Note II turn off the pressure sensor in standby mode. If you want to use pressure sensor during e.g. track recording, make sure your device maintains the pressure sensor on also when the screen goes off. <WRAP  round important>Some devices like e.g. Samsung Galaxy Note II turn off the pressure sensor in standby mode. If you want to use pressure sensor during e.g. track recording, make sure your device maintains the pressure sensor on also when the screen goes off.
- 
 </WRAP> </WRAP>
  
manual/user_guide/tools/altitude.txt · Last modified: 2022/04/08 11:54 by mstupka
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