A reinforcement information adjustment unit reduces an amount of information in reinforcement information by combining: update cycle adjustment processing to set an update cycle of the reinforcement information to be an integer multiple of a predetermined update cycle; geographic interval error value adjustment processing to reduce the number of geographic interval error values by selecting from among a plurality of the geographic interval error values each of which is an error at every predetermined geographic interval out of a plurality of error values, a geographic interval error value at every geographic interval that is an integer multiple of the predetermined geographic interval; and bit count adjustment processing to reduce a bit count of the error value for each error value. A reinforcement information output unit outputs, to an output destination, reinforcement information after being reduced in the amount of information by the reinforcement information adjustment unit.