Altitudes Settings and Elevations

Depending on the vario app you are using, different altitudes can be displayed and toggled through by touching the altitude field. The default altitude is the GNSS mean sea level altitude. A blinking altitude field upon startup means your phone is trying to obtain a GNSS Fix. This will take just a few seconds if any at all.

GNSS Altitudes

WGS84 altitude as well as mean sea level altitude are taken from any of the Global Navigation Satellite Systems (GNSS) including GPS as they are both relevant for paragliding. While WGS84 altitudes are easily available, they are not used or displayed during flight but rather logged according to the FAI guidelines for IGC loggers.

As a standard altitude theFlightVario vario app will try to provide altitudes with regard to mean sea level where possible fusing GNSS and barometric readings from the smartphone’s internal pressure sensor.

Barometric Altitudes 

Barometric altitudes are  calculated from pressure readings of the built-in pressure sensor.  Within the settings you can choose to set:

• QFE -  this is the pressure showing an altitude of zero when on ground of the aerodrome. QFE pressures can or rather should be fetched from the relevant aerodrome. To make that more easy we included a METAR lookup feature within the altitude settings. Simply select the four letter ICAO code to look it up.

• QNH - this is the virtual mean sea level pressure (MSL) showing aerodrome elevation when on ground of aerodrome. Just as with the QFE pressure QNH can be looked up using the METAR feature. 

You can also  set these barometric altitudes as well as a manual one directly on the main screen. Touch to toggle the altitude field. Long touch on the altitude field to set the altitude.

Flight Level (FL) is a special barometric altitude that is calculated with respect to a mean sea level pressure of 1013.25 hpa and reported in hundreds of feet. For example:

FL125:  125 x 100 = 12500 feet

Note: Please bear in mind that the accuracy for barometric altitudes depends on the exact phone barometer and its installation within the phone. Some smartphone barometer combination might have a bigger systematic offset than others. We have very good experience regarding Googles Nexus and Pixel Phones.

Elevations

Digital elevation models are used to provide an above ground level (AGL) information for the current location and a terrain profile for the direction of flight.

Distances

different types of distances are shown and calculated during the flight depending on the actual distance flown.

distance to start: this is the current distance to the start of your flight or where ever you started flying and logging with theFlightVario. the distance to start is being recalculated every second.

free distance: this is the longest one way distance between two logged GNSS positions of your current flight. The free distance is being recalculated roughly every 1000 meters from the last position it was calculated.

free 3TP distance: this is the 'longest distance' defined and calculated from a start and finish position and one to three turnpoints selected from logged GNSS positions. With no turnpoints specified beforehands, this distance is being recalculated on the fly roughly every 1000 meters from the last position it was calculated. To keep a balance of computing resources, free 3TP distance is being displayed as being greater or equal meaning some flight tracks may end up with an even bigger distance.

triangle distance: this is the closed course distance defined by a start and finish position and 2 or 3 turnpoints from logged GNSS positions. With no turnpoints specified beforehands, this distance is being recalculated on the fly roughly every 1000 meters from the last position it was calculated. 

Triangles are calculated for closing distances less than 20% of the triangle distance. For shortest leg distances greater or equal to 28% of the closing distance FAI triangle otherwise Free triangle is being displayed. For closing distances less than 5% of the triangle distance these are closed triangles otherwise open. For more information on distances you can check the FÉDÉRATION AÉRONAUTIQUE INTERNATIONALE website.

Note: the loss of height distance correction is currently not implemented.

Velocities

climb rate:  the climb rate in meter per second is being calculated from pressure readings of the internal barometer or received from external devices connected via either USB or Bluetooth.

speed over ground: is being provided from the GNSS information and denotes the speed over ground into the direction your glider is moving to which is not necessarily the direction your gliders nose is pointing to.

speed of the wind: speed of the wind is being calculated. This is beta, meaning  we’re not yet happy with the results or better the approach taken, so expect to have further updates on this!

Directions

magnetic north: If the magnetic compass is activated, this displays the current direction the phone, more precisely the upper end, is pointing to using the magnetic sensors of the phone. Make sure to optimally calibrate your phone’s compass by waving it a few times along the infinity pattern . If the compass is not activated the flight direction will be visualized. theFlightVario smartphone variometer features a worldwide compensation of the geomagnetic declination using the World Magnetic Model. 

flight direction: The bearing is being provided from the GNSS information and denotes the direction you and your glider are moving to. Please note, that while not moving the GNSS cannot calculate a bearing which is why the GNSS compass will jump around in this case.

wind direction: Make half a turn to get a rough wind direction and speed calculated. Make a full turn to get accurate readings. Accurate and precise while thermaling and soaring but degrading when flying straight. This is beta, meaning  we’re not yet happy with the results for flying straight or better the approach taken, so expect to have further updates on this!

Geographic Locations

theFlightVario currently supports two types of geo location information with text representations being displayed (alternating) in the upper left corner.

mountains: for selected countries mountains are visualized as symbols and the name of the closest mountain is displayed together with the current distance. This information is recalculated every couple of seconds

locations: depending on the network connection state of your smartphone the vario app tries to come up with a description of the location beneath you. This can be the name of the city or village you are currently approaching, the name of the broader area your flying over or the name of the road you see in front of you.

google map: with google maps activated a google map will be provided in the background. you can choose between  a classic google terrain map and a customized energy saving flatland map highlighting roads, rivers, lakes and mountain areas as whole.

flight trace: a flight trace connecting the last positions that have been logged is being displayed.

Other

Glide Ratio: Tells you how many units (e. g. meters) you are flying horizontal for one unit of flying vertically. The Glide Ratio is calculated with a regression approach and color coded

Heat Maps: Your own thermalling spots will be visualized using heatmaps.

Duration: The current duration of the flight.