A system and method is presented for performing optical measurements, including a light source configured to emit a light beam, a first pattern generator defining a first longitudinal axis and configured to project a first generated pattern, and a second pattern generator defining a second longitudinal axis and configured to project a second generated pattern. The first and second generated patterns have different angular divergency. The first pattern generator is a diffractive circle pattern generator, whereas the second pattern generator is a diffractive cross pattern generator. Adjustment of the first and second generated patterns with respect to each other cause the system to serve as an optical ruler for performing the optical measurements when the first and second generate patterns overlap or coincide with each other at certain points.
