Positioning method, positioning system, correction information generation method, correction information generation device, and positioning system relay station and terminal

A positioning system that includes a reference station having a processor, one or more relay stations, and terminals, the positioning system configured to:

• acquire, at a reference station, information for specifying a relay station communicating with the terminals among the one or more relay stations, and estimated coordinates of each of the terminals;
• determine, at the reference station, whether an available bandwidth between the reference station and the specified relay station is less than a predetermined value;
• when the available bandwidth is equal to or less than the predetermined value,
• generate, at the reference station, a single piece of correction information of an interferometric positioning method based on coordinates of the specified relay station,
• cause the reference station to transmit the single piece of the correction information to the terminals via the specified relay station by multicast, and
• cause each of the terminals to calculate coordinates of the each of the terminals by the interferometric positioning method using the single piece of the correction information;
• and
• when the available band width is greater than the predetermined threshold,
• generate, at the reference station, a plurality of pieces of correction information of the interferometric positioning method, each of which is generated based on the estimated coordinates of each of the terminals,
• cause the reference station to transmit each piece of the correction information to each of the terminals corresponding to the estimated coordinates used to generate the piece of the correction information, and
• cause each of the terminals to calculate coordinates of the each of the terminals by the interferometric positioning method using the each piece of the correction information.