A surveying system, comprising: a surveying instrument (1; 71) for measuring a three-dimensional position of a measured object (2; 72); and the measured object (2; 72), wherein the surveying instrument (1; 71) comprises a fan-shaped-laser-beam-emitting section that is configured to rotationally emit N-shaped light in a horizontal plane to search for the measured object (2; 72), wherein the N-shaped light is composed of a first and a third fan-shaped laser beam (3a, 3c) as well as a second fan-shaped laser beam that is inclined with respect to the first and the third fan-shaped laser beam (3a, 3c), wherein the surveying system comprises a detecting section (6, 62, 60; 60, 73) distributed over the surveying instrument and the measured object or comprised by the surveying instrument that is configured to detect the direction of the measured object (2; 72) by using a first, a second and a third light signal (70a, 70b, 70c) that are based on the first, the second and the third fan-shaped laser beam (3a, 3b, 3c) reflected by the measured object (2; 72) and received by the surveying instrument (1; 71) or received by the measured object (2; 72), wherein the surveying instrument (1; 71) further comprises: a tracking optical system including a tracking-light-emitting section that is configured to emit a tracking light in a direction detected by the detecting section (6, 62, 60; 60, 73) and a tracking-light-receiving section that is configured to receive the tracking light reflected by the measured object (2; 72); a distance-measuring optical system including a distance-measuring-light-emitting section that is configured to emit a distance-measuring light to the measured object (2; 72) caught by the tracking-light-receiving section; and driving sections and that are configured to drive the tracking optical system and the distance-measuring optical system so as to collimate with respect to the measured object (2; 72), wherein an emitting area of the fan-shaped laser beams (3a, 3b, 3c) is wider than that of the tracking light, wherein the detecting section (6, 62, 60; 60, 73) is configured to calculate an elevation angle γ from a ratio of the time intervals between the first and the second light signal (70a, 70b) and the first and the third light signal (70b, 70c), an inclined angle θ of the second fan-shaped laser beam, and an enlarged angle δ of the fan-shaped laser beams (3a, 3b, 3c), and to calculate a horizontal angle to the measured object (2; 72) by a time interpolation method based on the receiving time of the lights signals (70a, 70b, 70c) and a horizontal angle detected in a predetermined time interval, thereby detecting the direction of the measured object (2; 72), wherein the fan-shaped-laser-beam-emitting section and the tracking-light-emitting section are configured to rotate in a vertical plane, wherein the fan-shaped-laser-beam-emitting section and the tracking-light-emitting section are configured to emit respectively the fan-shaped laser beams (3a, 3b, 3c) and the tracking light in the same direction in the horizontal plane, and wherein the tracking-light-emitting section is configured to change the emitting direction of the tracking-light-emitting section in the vertical plane when the tracking-light-receiving section does not receive the tracking light reflected by the measured object (2; 72). a surveying instrument (1; 71) for measuring a three-dimensional position of a measured object (2; 72); and the measured object (2; 72), a tracking optical system including a tracking-light-emitting section that is configured to emit a tracking light in a direction detected by the detecting section (6, 62, 60; 60, 73) and a tracking-light-receiving section that is configured to receive the tracking light reflected by the measured object (2; 72); a distance-measuring optical system including a distance-measuring-light-emitting section that is configured to emit a distance-measuring light to the measured object (2; 72) caught by the tracking-light-receiving section; and driving sections and that are configured to drive the tracking optical system and the distance-measuring optical system so as to collimate with respect to the measured object (2; 72),