PROBLEM TO BE SOLVED: To improve the accuracy of determining the active state of an observed person based on a detection signal obtained by an inertial sensor.SOLUTION: A sensor information processing apparatus calculates an extending-time wavelength being the length of a signal waveform equivalent to a trajectory drawn in a time region by the detection signals obtained by the inertial sensor per a unit time, and determines the active state of an observed person by means of the inertial sensor, on the basis of the extending-time wavelength.SELECTED DRAWING: Figure 6【課題】慣性センサの検出信号に基づく被観測者の活動状態の判定精度を向上する。【解決手段】単位時間あたりに慣性センサの検出信号が時間領域で描く軌跡に相当する信号波形の長さである伸展時波長を算出し、伸展時波長に基づいて、慣性センサによる被観測者の活動状態を判定する。【選択図】図６
