Sunlight speckle photography

A technique is being developed based on laser and whitelight speckle photography using the Sun as the light source. It is applicable for in-plane displacement analysis of large structures and bodies. For the method to be applicable the surface of the object must have a granular texture of such contrast and definition that it can be resolved by a camera lens. Rough concrete, sand, rock and boulders create a suitable speckle pattern in bright sunlight; the only proviso is that the granular 'signature' of the surface does not change. The application of the method to measure the full-field movement of debris covered glaciers is illustrated.<
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