During the trip this altitude value is much more pre-
cise than the one obtained from the GPS module,
provided the weather conditions (air pressure, tem-
perature) do not change significantly.
If the bike is parked for an extended period of time
during a tour (e.g. at the lunch break), and the
weather conditions change markedly during this
time, this will have no effect on the altitude re-
corded, because variations of the air pressure are
ignored when the bike is not moving. You need not
worry about the system recording a variation of the
altitude value while taking a rest break.
Depending on the weather conditions the following
deviations in the measured barometric altitude are
to be expected:
- in the case of an unstable high pressure area
> 25 m/h
- in the case of stable good weather 5 to 25 m/h
- in the case of stable weather -5 to 5 m/h
- in the case of stable rainy weather -25 to -5 m/h
- in the case of an unstable low pressure area
< -25 m/h
Determining the altitude
A HDOP value of 1 is the highest possible geomet-
ric positioning arrangement of the satellites, a value
around 6 is yet moderate. HDOP values higher than
10 are too inaccurate for a measurement (see Wiki-
pedia -> http.//en.wikipedia.org/wiki/HDOP).
When using additional systems for the augmenta-
tion of the accuracy (e.g. EGNOS), it may also hap-
pen that a HDOP value below 1 is shown.
Start a new tour to use the more precise altitude
from the GPS module as the start altitude for the
barometric altitude sensor.
During the tour the altitude measured by the baro-
metric sensor is used and displayed.
Current data
Trip time:
00:00:00
Heart rate:
---
Temperature °C:
19.8
Altitude AMSL m:
322.4
Incline %:
0.0
If you want to have a more accurate evaluation of
the start altitude then please wait until enough satel-
lites are received (Scan display / GPS data).
GPS data
Latitude: 49.503538°
Longitude: 10.963827°
Altitude AMSL m:
314.7
Satellites: 7
Fix, HDOP:
3D, 1.2
OPERATING premium
What does „Fix“ mean in the GPS data?
Depending on the number of satellites received and
where these are positioned in the sky, the GPS po-
sition can be determined as „2D“ ( min. 3 satellites)
or „3D“ (min. 4 satellites).
In case the location can not be determined accu-
rately (e.g. few satellites, unfavourable satellite
positions, etc.) „2D“ will be displayed (2 dimensions
longitude and latitude can be measured). In case of
a „3D“ display, the third dimension (altitude) can be
measured on top.
What does „HDOP“ mean in the GPS data?
Depending on the number of satellites received and
where these are positioned in the sky, the display
value HDOP (horizontal dilution of precision) can be
lower or higher.
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