Abstract: An adaptive slant range compensator, suitable for use with an optical mapg system for remote viewing, comprises a logarithmic amplifier which compresses an analog input signal having a wide range of values to a tractable range. An analog-to-digital (A/D) converter converts the compressed signal to a 10-bit binary number. The digitized compressed data is then used to address antilog programmable read-only memories (PROMs) which contain the antilog of the address data in scientific notation. Control and data processing circuits are used to accumulate sample scans from the antilog PROMs in a summing memory, calculate an average scan from the accumulated sample scans, and transfer this average to a working memory. The data stored in the working memory is used to drive an attenuation/amplification network that divides succeeding scans by the stored average scan. In this way, the inverse transfer function is applied to the analog input signal, which forms another input to the attenuation/amplification network.

Abstract: An optical system, to be used with an illuminating source, maps objects lted in an underwater environment. A first optical means is adapted to receive light from the illuminating source for transmitting the illumination to the object area to be mapped. A second optical means comprises an input means, adapted to receive reflected light from the illuminated object area, or plane; and an output means for conformally transforming images of all objects in the object plane to an image plane, located externally to the second optical means. A conformal transformation at a point is one which preserves angles between every pair of curves through the point. The optical system further comprises means located between the second optical means and the image plane for filtering or masking light propagating between the two, to thereby reduce backscatter.

Abstract: An improved optical measuring system for measuring the deflection or dispement of a beam of coherent light energy is disclosed as including a Faraday rod having magneto-optical properties in conjunction with a polarizer and analyzer at the entrance and exit pupils thereof and a photodetector with lock-in amplifier which, in turn, controls a magnetic control means operatively associated with the Faraday rod.

Abstract: An improved viewing port for underwater oceanographic vehicle provides for establishing a standard length optical test path in the underwater environment with no modifications or additional passages through the hull of the vehicle.