Sensor control method executed by air-conditioning apparatus

A sensor control method executed by an air-conditioning apparatus including a linear infrared sensor constituted by a plurality of infrared light-receiving elements, the sensor control method comprising:

• acquiring a first thermal image by scanning an air-conditioned space using the infrared sensor in accordance with a first scanning scheme, the air-conditioning apparatus being placed in the air-conditioned space;
• extracting a subject thermal image from the first thermal image, based on a difference between a background thermal image of the air-conditioned space when no subject is present therein and the first thermal image;
• determining a second scanning scheme different from the first scanning scheme, when a size of the extracted subject thermal image is equal to or smaller than a predetermined size, wherein the predetermined size is smaller than a size of the first thermal image;
• and
• acquiring a second thermal image by scanning an area corresponding to the extracted subject thermal image of which the size is equal to or smaller than the predetermined size using the infrared sensor in accordance with the determined second scanning scheme, wherein the area is an area in the air-conditioned space.