Abstract: Provided is an altitude calculation method for a flying body including calculating an altitude of the flying body by using information on horizontal coordinates of the flying body, a reception signal strength of a radio signal, and altitude calculation auxiliary information obtained in advance.

Abstract: A printing device includes: a printing unit printing on a recording paper; a feeder unit having a roller that rotates about a shaft and feeds the recording paper and a motor that rotates the shaft; a detection unit detecting the rotation of the shaft; and a control unit controlling the printing unit. The control unit calculates an electrifying time during which the printing unit is electrified and a non-electrifying time during which the printing unit is not electrified following the electrifying time, based on a detection signal from the detection unit. When the calculated non-electrifying time is less than a predetermined time, the control unit corrects the non-electrifying time in such a way that the non-electrifying time becomes equal to or longer than the predetermined time, and causes the printing unit to print.