Dead reckoning (also called path integration) is the
process by which a navigating organism derives its current position relative
Earthbound reference point from its own locomotion. Dead reckoning requires
the continuous estimation of changes in direction and location
signals and the computation of position on the basis of these
(i) Hymenopterous insects measure rotations and translations mainly
help of optical references such as the Sun and translational visual flow.
By contrast, mammals are able to estimate their position on the basis of
purely ‘internal’ information; that is, signals generated in
system by inertial forces, somatosensory feedback, and efference copies
(copies of central commands that control the performance of rotations and
translations). Obviously, the assessment of the angular and linear
components of locomotion is much more precise if it is assisted by
external references than if this is not the case.
(ii) Only man-made dead reckoning systems yield precise position information
through the twofold integration over time of inertial signals deriving
angular and linear acceleration. On the biological level, all species tested
so far seem to rely on a simplified form of path ‘integration’:
test situations, arthropods and mammals (including humans) commit
similar systematic errors. This suggests that species from unrelated taxa
update position according to a similar algorithm.