Target tracking device and storage medium storing target tracking program

A target tracking device comprising:

• a communication device configured to perform communication with a plurality of observation satellites configured to observe a target;
• and
• a processor configured to estimate a position of the target based on observation information that represents information of the target observed by the plurality of observation satellites,
• wherein the processor is further configured to execute:
• selecting, based on the position of the target, two or more selected satellites configured to observe the target, among the plurality of observation satellites;
• determining an observation schedule for each of the two or more selected satellites to observe the target;
• transmitting an observation request signal that represents the determined observation schedule to a corresponding selected satellite of the two or more selected satellites;
• estimating, based on two or more pieces of the observation information respectively observed by the two or more selected satellites, the position of the target;
• and
• outputting an output signal that represents the estimated position of the target, and
• wherein in the observation schedule a first time when a first selected satellite of the two or more selected satellites observes the target is same as a second time when a second selected satellite of the two or more selected satellites observes the target, and
• wherein the selecting includes:
• estimating a moving route along which the target moves;
• and selecting, based on the estimated moving route, the two or more selected satellites.