Patent ID: 8848180

Claim:
A reference system, comprising: a light-emitting device locatable at a first location, the light-emitting device including— a first light emitter configured to emit a planar light region having a vertical orientation, a second light emitter configured to emit an indicator light beam, a slope of the indicator light beam being adjustable to change a position of the indicator light beam within a vertical adjustment field, a housing including a base operably connected to the first and second light emitters, and an alignment-adjusting mechanism configured to rotate the first and second light emitters in concert relative to the base about a vertical axis so as to rotationally reposition the planar light region and the indicator light beam; a detector locatable at a second location remote from the first location, the first and second locations being situated such that the planar light region is incident on the detector when the planar light region is in an aligned state, the light-emitting device is at the first location, and the detector is at the second location; and a controller operably associated with the alignment-adjusting mechanism and the detector, wherein— the controller is configured to wirelessly receive one or more signals from the detector, the detector is configured to detect a misaligned state of the planar light region based on a shift of the planar light region from the aligned state and to wirelessly transmit or stop wirelessly transmitting the one or more signals to the controller in response to detecting the misaligned state, and the controller includes memory and processing circuitry, the memory storing instructions that, when executed by the controller using the processing circuitry, cause the alignment-adjusting mechanism to rotate the first and second light emitters in concert relative to the base about the vertical axis in response to the one or more signals or an absence of the one or more signals so as to move the planar light region from the misaligned state toward the aligned state and to correspondingly reposition the indicator light beam.