Patent ID: 8170282

Claim:
A computer-readable storage medium that provides instructions that, if executed by a machine, will cause the machine to perform operations comprising: accessing data associated with an image of a portion of Earth, the data including reflectance values; masking a first portion of pixels within the image with a cloud and land mask based on spectral flatness of the reflectance values associated with the pixels, wherein the reflectance values comprise a near infrared (NIR) reflectance value and a visible reflectance value for each of the pixels of the image and wherein the spectral flatness of the reflectance values is determined based on a ratio of the NIR reflectance value to the visible reflectance value for each of the pixels; unmasking a given pixel selected from the first portion of pixels when a threshold number of localized pixels surrounding the given pixel are not masked by the cloud and land mask; generating a spatial variability image based on spatial derivatives of the reflectance values of the pixels which remain unmasked by the cloud and land mask; and thresholding the spatial variability image to identify one or more regions within the image as possible ship detection regions.