A behavior of a walker is detected according to combination of detection
of the walking behavior on a level and an altitude variation of the
walker to more accurately detect the behavior of the walker. A burned
calorie can be obtained according to the type of the walking behavior. An
altitude variation can be obtained more accurately by integrating
altitude variation only at sections with vertical movement during
walking. A stride is estimated according to the behavior of the walker in
consideration of the vertical movement. Obtained position and traveling
direction are used for compensating values in inertial navigation system.
The behavior with and without vertical movement is used in a walker
navigator and a worker observing system including a worker terminal
carried by the walker for detecting the behavior of the worker and a
worker observing terminal for providing the detected position and
behavior of the walker.