An apparatus and system for use in determining location of a celestial body are presented. The apparatus comprises: a polarizer comprising an array of polarized light filter cells and a light sensor array. The array of polarized light filter cells comprises at least a first polarization direction and a second polarization direction different from said first polarization direction. And the polarizer thereby produces polarized light of at least first and second different polarizations. The light sensor array is configured to receive the polarized light from the polarizer and produce data indicative of a pattern of at least one of light polarization intensity and direction. The pattern is indicative of at least one of azimuth and elevation of the celestial body to be located.