Nanoradians level high resolution autocollimation method based on array slits.

This study developed a detailed mathematical model to elucidate array slits imaging and linear CCD acquisition. Frequency domain analysis revealed the relationship between system parameters and spot image aliasing noise. Aliasing noise was reduced through optimized array slits design and linear CCD parameter selection, improving angular measurement resolution and stability. Unlike in traditional methods, only 8 array slits were required to achieve nanoradian-level resolution and stability. The device achieved an angular measurement resolution of 0.0005 arcsec over a measurement range of ±400 arcsec. Static repeatability is 0.0003 arcsec, and stability is 0.0061 arcsec in 2 hours.