Patent ID: 7055253

Claim:
A surveying instrument, comprising: a surveying instrument body rotatable about each of a vertical axis and a horizontal axis; and a first collimator optical system comprising a first lens having a first optical axis and a second collimator optical system comprising a second lens having a second optical axis different from the first optical axis, each of said first and second collimator optical systems being positioned in said surveying instrument body to collimate said surveying instrument relative to a survey point, a viewing angle of said second collimator optical system being smaller than a viewing angle of said first collimator optical system, wherein a first collimating operation is performed with said first collimator optical system before a second collimating operation is performed with said second collimator optical system, and each of said first and second collimator optical system comprise a separate light source for projecting light rays toward said survey point to collimate said surveying instrument relative to said survey point.