Cross-diffractive optical elements for wide angle geometric camera calibration.

Area of Science:

• Optics
• Photogrammetry
• Optical Engineering

Background:

• Diffractive optical elements (DOEs) enable camera calibration via 2D diffraction grids.
• Current DOE fabrication limits accuracy, functionality, and camera/angle scope.

Purpose of the Study:

• To present a low-cost solution for enhancing camera calibration using commercially available DOEs.
• To expand the calibration field of view for wide-angle aerial cameras.

Main Methods:

• Utilized two large, commercially available, crossed phase DOEs generating 15x15 dot grids.
• Employed primary and secondary diffractive orders as calibration targets.
• Developed a technique to overcome DOE fabrication limitations.

Main Results:

• Demonstrated a valuable calibration tool for wide-angle aerial cameras.
• Successfully expanded the calibration field of view beyond primary orders.
• Achieved accurate camera calibration using secondary diffractive orders.

Conclusions:

• The proposed method offers a cost-effective approach to camera calibration.
• Leveraging secondary diffractive orders enhances calibration capabilities.
• This technique overcomes limitations of traditional DOE fabrication for photogrammetry.