Wind - LX Navigation Zeus User Manual

2.2.11 Wind

LX Zeus is able to measure wind
using different methods; these can
be selected in the Wind menu.
Wind calculation results are shown
as a standalone indicator on the
main graphic page and also as a NavBox, if set.
The pilot can choose between two circling
methods: one which measures wind during circling
flight and the second method using straight flight.
The wind calculation is used for numerous
calculations (TDT, Final glide, etc.).
2.2.11.1 Circling model

Speed difference is based on the variation of ground speed (GS) using the wind detected whilst in
circling flight. This method is only active during circling. (In straight flight the wind data remains
unchanged). The process is started automatically once circling is detected. After two circles the
wind indication (direction and speed) will be updated and displayed. This method is based on the
ground speed being affected by the wind. GS is, of course, at its maximum with a tailwind and
minimum with a head wind and this is used for the GS difference calculation method. To get a
result the pilot should do two turns as a minimum, more turns will improve the result. Please note
that up to 90 degrees turn or more is required as some time is needed to detect circling status. It
is important to keep constant IAS speed during circling. However, other factors are also taken
into account to cancel out the fluctuations of airspeed while circling. This wind calculation method
is the default and preferred approach.

Position drift calculates wind regarding to position change during circling. Such a method needs
more circles than speed difference (from 4 up to 8). The number of circles should be set in Drift
circles option. If both methods, straight model and position drift are selected, the Zeus will give a
combined result.
2.2.11.2 Straight model

None: If you select none, you will have the wind from the latest circling method.

Iterative: This method will update the wind in straight flight. It is a special method developed by
LX Navigation and delivers accurate wind measurements by using sophisticated algorithms. With
this method, you do not need a compass. The pilot will, however, get good wind speed and
direction results. This method does not supplement Head/Tail method and, for best results, a
constant IAS is required.

Compass: The Compass system requires the compass module to be connected to the unit using
the 485 bus or CAN bus. Wind calculation is based on the wind triangle method. Under this
approach, airspeed, ground speed and wind create a triangle of vectors. A compass device offers
magnetic heading, which defines the direction of the airspeed vector. To measure wind using a
compass straight flight speed and direction must be kept as stable as possible.
LX Zeus v4.0.2
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