HEL Beam Alignment
Optical Physics Company has developed a concept for precise alignment of the high energy laser (HEL) beams based on sensing the atmospheric aerosol backscatter, thereby observing the actual track of the HEL through the atmosphere, permitting accurate boresight correction.
Through simulation and lab testing, OPC first showed that, based on atmospheric backscatter, boresight error could be corrected with ten times better accuracy than the required one microradian. This corresponds to 1/26 λ/D for a 40 cm aperture.
Second, OPC demonstrated by a field test in a relevant and traceable environment, that the HEL energy backscattered by atmospheric aerosol and target can be viewed through the optics backscatter of the HEL and could be used to correct boresight error.
It is also possible to use this same technique to correct for tracking errors at high bandwidth.
At the present time, technology maturity for the precision HEL to tracker alignment technology stands at TRL 5.