US 7,321,420 B2
Survey system
Satoshi Yasutomi, Matsuda-machi (Japan); Minoru Chiba, Matsuda-machi (Japan); and Nobuyuki Nishita, Matsuda-machi (Japan)
Assigned to Sokkia Co., Ltd., Atsugi-shi (Japan)
Filed on Mar. 02, 2006, as Appl. No. 11/365,823.
Claims priority of application No. 2005-058979 (JP), filed on Mar. 03, 2005.
Prior Publication US 2006/0197944 A1, Sep. 07, 2006
Int. Cl. G01B 11/26 (2006.01)
U.S. Cl. 356—141.3 6 Claims
OG exemplary drawing
 
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.