[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 (θ o ) 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.
1. A survey system comprising a target and a surveying instrument that automatically tracks or collimates the target,
the target comprising: a direction angle sensor that measures a surveying-instrument direction angle obtained when the target is directed toward the surveying instrument; and a measurement command means for transmitting the surveying-instrument direction angle and a measurement command to the surveying instrument,
the surveying instrument comprising: an angle measuring means for measuring a target direction angle that indicates a direction of the target; a measurement means for automatically collimating the target and performing measurement when the measurement command is received; an angular-difference calculating means for calculating an angular difference between the surveying-instrument direction angle and the target direction angle; a target-direction-angle estimating means for calculating an estimated target direction angle from the angular difference calculated at last measurement and from the surveying-instrument direction angle transmitted from the target at present measurement; and a rotation means for directing a body of the surveying instrument in a direction of the estimated target direction angle.
2. A survey system comprising a target and a surveying instrument that automatically tracks or collimates the target,
the target comprising: a direction angle sensor that measures a surveying-instrument direction angle obtained when the target is directed toward the surveying instrument; an angular-difference calculating means for calculating an angular difference between the surveying-instrument direction angle and a target direction angle that indicates a direction of the target-transmitted from the surveying instrument; a target-direction-angle estimating means for calculating an estimated target direction angle from the angular difference calculated at last measurement and from the surveying-instrument direction angle obtained when the target is directed toward the surveying instrument at present measurement; and a measurement command means for transmitting a measurement command including the estimated target direction angle to the surveying instrument,
the surveying instrument comprising: an angle measuring means for measuring a target direction angle; a measurement means for automatically collimating the target and performing measurement when the measurement command is received; a measured-value transmitting means for transmitting the target direction angle to the target; and a rotation means for directing a body of the surveying instrument in a direction of the estimated target direction angle.
3. The survey system as described in claim 1 or 2 , wherein the rotation means determines a rotational direction having a smaller angular difference selected from between a clockwise angular difference and a counterclockwise angular difference, concerning a present direction angle at which the body of the surveying instrument is directed and the estimated target direction angle.
4. The survey system as described in claim 1 or 2 , wherein the angular-difference calculating means calculates a representative value of angular differences that have hitherto been obtained whenever the angular differences are calculated, and the target-direction-angle estimating means uses the representative value as the angular difference.
5. The survey system as described in claim 1 or 2 , wherein the target includes a guide light transmitter that emits guide light indicating a direction of the target, and the surveying instrument includes a direction detector that detects the direction of the target by receiving the guide light.
6. The survey system as described in claim 1 or 2 , wherein the direction angle sensor is a magnetic sensor.