The invention discloses a
sun tracking method based on an
underwater Snell window external polarized
light field, which belongs to the technical field of
underwater polarized light navigation, and comprises the following steps: calculating an
underwater observation vector
elevation angle under a horizontal attitude according to attitude angle information; the method comprises the following steps: acquiring an underwater Snell window external polarized light image under a
horizontal coordinate system, performing Stokes vector calculation on the underwater Snell window external polarized light image, and constructing an incident light coordinate
system after solving a polarization angle image outside a Snell window; deducing a polarization E-vector corresponding to each pixel position under a
horizontal coordinate system by using a relation between the polarization E-vector and an incident light coordinate
system; according to the polarization E-vector, combining geometric constraints of the polarization E-vector and the underwater refracted
sunlight vector to derive the underwater refracted
sunlight vector; and according to the underwater refracted
sunlight vector, calculating an atmospheric incident sunlight vector, and calculating a
zenith angle and an
azimuth angle of the atmospheric incident sunlight vector. According to the method, the accuracy of resolving the solar
azimuth of the polarized
light field outside the Fresnel window in the complex underwater environment is improved.