[Problem] In a surveying instrument that automatically tracks or collimates a target, the target that is moved to a measurement point and is placed there can be found in the shortest possible time.
[Solution Means] In a survey system made up of a target (60) and a surveying instrument (50) that automatically tracks or collimates the target, the target is provided with a direction angle sensor (86) that measures a surveying-instrument direction angle (θta, θtb) obtained when the target is directed toward the surveying instrument, whereas the surveying instrument is provided with a horizontal angle measuring portion that measures a target direction angle (θsa, θsb, θsc) indicating the direction of the target. An estimated target direction angle (θsb) is calculated from an angular difference (θo0) between the surveying-instrument direction angle (θta) and the target direction angle (θsa) obtained at the last measurement and from the surveying-instrument direction angle (θtb) obtained at the present measurement. The instrument body (52) is directed in the direction of the estimated target direction angle.