1. A method of determining orientation of an object, the method comprising: recording raw image data of the sky using a sky polarimeter; calculating Stokes parameters (S 0 , S 1 , S 2 ), degree of linear polarization (DoLP) and angle of polarization (AoP) from the image data; detecting obscurants and filtering the obscurants from the image data to produce a filtered image; obtaining position/orientation data of the object; finding the Sun azimuth and elevation in the filtered image by performing a coordinate transform on a measured polarization pattern to generate a scanning AoP image; determining one or more of the roll, pitch, yaw, latitude and longitude of the object using the filtered image; when yaw is determined using the filtered image, calculating platform yaw based on the angle between the line intersecting the Sun and the zenith and expected Sun/azimuth position for a given date and time; performing minimum detection and extracting a region of the image containing the Sun and zenith; applying morphological erosion on a binary image to reduce the detected minimum region to a single line; and extracting a sun-zenith line.