Abstract: In order to solve a conventional problem that precision deterioration that cannot be determined by only a DOP, a positioning system is provided which comprises: a receiver for receiving signals from a plurality of positioning satellites to output data received from satellites; a satellite selector for selecting a plurality of combinations of positioning satellites to be objects of positioning calculation based on the data received from satellites to output satellite combination data; a positioning calculator for performing positioning calculation based on the data received from satellites and the satellite combination data to output positioning results thereof; a velocity detector for detecting a velocity of the positioning system to output velocity data; and a positioning output determining unit for selecting a positioning result closest to a predicted position out of the positioning results to output the positioning result as a positioning output.

Abstract: In order to solve a conventional problem that precision deterioration that cannot be determined by only a DOP, a positioning system is provided which comprises: a receiver for receiving signals from a plurality of positioning satellites to output data received from satellites; a satellite selector for selecting a plurality of combinations of positioning satellites to be objects of positioning calculation based on the data received from satellites to output satellite combination data; a positioning calculator for performing positioning calculation based on the data received from satellites and the satellite combination data to output positioning results thereof; a velocity detector for detecting a velocity of the positioning system to output velocity data; and a positioning output determining unit for selecting a positioning result closest to a predicted position out of the positioning results to output the positioning result as a positioning output.

Abstract: An apparatus and formatting method formats a disk without using an index pulse generated by hardware for every disk rotation. A last data block gap and a track gap which are longer than a standard track gap length are first written. Even if there is a fluctuation in rotation cycle time during formatting, a last sector of each track is written over a beginning of the track gap. When writing to a last sector is complete, formatting of a track is complete. When a head is stably positioned at a track to be formatted, formatting of the track is started.