Polychromatic Holographic Correlation Techniques for Enhancing Resolution in Remote Sensing Applications

Abstract

In optical remote sensing by photo-reconnaissance satellites or in ground-observation by orbiting space telescopes, the diffraction-limited theoretical resolution possible, is degraded by accidental & vibratory motion of the imaging camera, defocussing, atmospheric turbulence effects on satellite-pictures transmitted, etc. For instance, an orbiting space telescope (height, h ′ = 275   km above earth) with an effective focal length, f = 57.6m and equipped with a CCD camera with pixel, d = 15 microns, has a theoretical resolution: R = ( h ′ d / f ) → = 7.16   cm ( ! ) on ground; however, in practice due to image-degradation, the feasible resolution is of 10-15m only(which can be improved with rigid satellite attitude-control, to 1-2m).