Information Regarding The Activation Altitude - AAD Vigil Cuatro User Manual

3.4. Information regarding the Activation Altitude

Please be aware that the Vigil Cuatro functions are based on measured air pressure. This parameter permits the
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calculation of the exact altitude, in function of the registered air pressure, as well as the vertical speed related to a
pressure variation in a certain period of time.
For information: The Vigil Cuatro is able to register pressure differences of 0,1 hPa which is equivalent
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to an altitude difference of only ± 2,6 ft (or 0,8 meter)!
Important note: The registered pressure by the sensor will vary, according to the body position of the
skydiver (face to earth or back to earth) up to 10 hPa (=mbar) which is equivalent to +-260 ft (+-79 m)!
Example: Let's consider two skydivers in free fall, at exactly the same altitude but one is falling back to earth
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and the second one is falling face to earth.
The influence of their falling position on their respective AAD reading is as follows:
(I) back to earth
(II) Face to earth
Depression zone (burble) AAD or pressure sensor
located in depression zone
No influence
Both at the same altitude Y
(burble)
Pressure sensor location
Pressure = X hPa – 10 hPa
Pressure = X hPa
Vigil Cuatro in depression zone will register an up to 10 hPa
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Vigil Cuatro will register a pressure of X hPa
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lower pressure, notwithstanding they are at the same level
The stated or real altitude  y ft (or m)
The stated altitude  Y +(±260 ft) or +(±79 m)