Improved active-tracking performance through Hadamard speckle contrast reduction

We report wave-optics simulation results and benchtop experimental findings that demonstrate reduced centroiding error through a Hadamard speckle contrast reduction (HSCR). The method involves projecting multiple orthogonal phase patterns onto an actively imaged object within a single camera resolution cell and integration time. Ideally, performance improves in proportion to the square root of the number of such phase realizations applied. Using 16 subpixels per camera pixel, our simulated track performance consistently meets this expectation with a decent experimental agreement, particularly at smaller object sizes. This outcome has promising implications for active tracking and wavefront sensing, extending the utility of HSCR beyond its known benefits to coherent image quality.