This invention discloses a three-degree-of-freedom
autocollimation angle
measurement device and method based on a crosshair
reticle, comprising a probe
system, a target mirror
system, and a calculation
system. The probe system emits a collimated beam containing crosshair image information into the target mirror system. The target mirror system separates the collimated beam containing crosshair image information into two reflected beams parallel to the
optical axis, each reflecting beam containing crosshair image information. The probe system also receives the two reflected beams parallel to the
optical axis and images the crosshair images corresponding to the two reflected beams. The calculation system calculates the
pitch and
yaw angles of the target based on the initial and current coordinates of the crosshair image corresponding to one reflected beam parallel to the
optical axis, and calculates the roll angle of the target based on the initial and current tilt angles of the crosshair image corresponding to the other reflected beam parallel to the optical axis. This invention enables rapid and high-precision three-degree-of-freedom angle measurement of distant targets.