Shock waves will form by turning supersonic or locally supersonic flow and result in an increase in the freestream density downstream of the shock. This increase leads to optical distortions that limit the effectiveness of aircraft-mounted laser systems. In this paper, analytic expressions are developed to describe these optical distortions in terms of the optical-path difference (OPD). Pupil-plane disturbances imposed by the shock are studied for two cases: when the shock is parallel to the propagation direction and when the shock is on an angle relative to the propagation direction. Upon propagation from the pupil plane, the analysis shows that shock-induced phase discontinuities can sometimes cause the irradiance pattern in the image plane to bifurcate. Despite a large amount of tilt in the pupil plane, the bifurcated irradiance pattern does not map to a proportional shift in the image plane. The implications that these findings have on Shack–Hartmann wavefront sensor (SHWFS) data are also explored. The results show that least-squares reconstruction from the SHWFS data yield accurate estimates of the change in OPD across the shock when the magnitude of the phase difference Δ ϕ caused by the shock is between 0 and approximately 0.5 π    [ rad ] . However, when | Δ ϕ | > 0.5 π    [ rad ] , the results show that least-squares reconstruction begins to severely underestimate the change in OPD across the shock. Such results will inform future efforts looking to develop aircraft-mounted laser systems.


    Access

    Download


    Export, share and cite



    Title :

    Effects of Shock Waves on Shack–Hartmann Wavefront Sensor Data


    Contributors:

    Published in:

    AIAA Journal ; 61 , 6 ; 2356-2368


    Publication date :

    2023-06-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Shack-Hartmann wavefront sensor testing of aero-optic phenomena

    Neal, Daniel / Hedlund, Eric / Lederer, Melissa et al. | AIAA | 1998


    Shack-Hartmann wavefront sensor testing of aero-optic phenomena

    Neal, D. R. / Hedlund, E. / Lederer, M. et al. | British Library Conference Proceedings | 1998


    WAVEFRONT SENSING Shack-Hartmann wavefront sensors move into new applications

    Beyerlein, M. / Pfund, J. | British Library Online Contents | 2006


    Shack-Hartmann wavefront sensor for laser beam analyses [4493-45]

    Zavalova, V. Y. / Kudryashov, A. V. / SPIE | British Library Conference Proceedings | 2001


    Aspheric metrology with a Shack-Hartmann wavefront sensor [4419-500]

    Greivenkamp, J. E. / Smith, D. G. / Gappinger, R. O. et al. | British Library Conference Proceedings | 2001