SUUNTO AMBIT2 R User Guide - Manual (Page 111)

14 FUSEDSPEED
FusedSpeed
TM
is a unique combination of GPS and wrist
acceleration sensor readings for measuring your running speed
more accurately. GPS signal is adaptively filtered based on wrist
acceleration, giving more accurate readings at steady running
speeds and a quicker response to changes in speed.
FusedSpeed TM will benefit you the most when you need highly
reactive speed readings during training, for example, when running
on uneven terrain or during interval training. If you temporarily
lose GPS signal, for example, because buildings block the signal,
Suunto Ambit2 is able to continue showing accurate speed readings
with the help of the GPS calibrated accelerometer.
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