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Text in French; summary in English.

See also AD-A076 679.

Presented at the American Society of Mechanical Engineers/CSME Joint Pressure Vessel and Piping Conference, held in Montreal, Canada, 25-30 Jun 78, paper-78-MAT-6 1978.

Measurements on the reflectance R of A guided-beam splitter have been performed. The fabrication method, based on the use of a thin wire as a mask, produces a groove with a parabolic thickness profile in a planar waveguide. The experimental results demonstrate that the theroretical expression R=tanh-Squared delta describes well the observed phenomena, especially when the TMo mode is incident on the groove. Additional applications of this device for polarization analysis and mode selection are also discussed. (Author), Summary in French.

This report describes an interactive digital image-processing system that includes a minicomputer, a programmable array transform processor and on-line image digitizing and display equipment, and illustrate typical applications in the areas of image restoration and enhancement. A photograph blurred by a defocused camera is analyzed to determine the nature of the blur and is restored. Image-enhancement technique, based on the properties of human vision or on the image-formation process, are applied to visible light, infrared and radiographic images., in French.

A FORTRAN program used to translate man-readable statements into machine-understandable code and to simulate a program written for the Intel 8048/8748/8035 microcomputers is described. This program allows programming of the microprocessor in symbolic language and the use of labels for jump instructions. The simulator duplicates exactly the behavior of the microcomputer in a real-world application. It is also possible to simulate interrupts and print out intermediate results. (Author), Summary in French.

Ranging has been demonstrated with an experimental laser rangefinder employing a hybrid TEA-CO2 laser transmitter and heterodyne-detection receiver. A description of the system, including its operating principles and performance characteristics, is presented. Ranging results are given to 5 km on targets with previously measured characteristics and to 32 km on natural targets. The application of TEA-CO2 laser transmitters in optical radar systems capable of detecting and tracking high speed targets is briefly discussed. (Author), in French.

This report describes a digital processing technique for measuring local isotropic and directional textural features, and we use the textural information so obtained to perform automatic target detection. The present targets, which consist of an APC, a tank, a truck and a helicopter located against backgrounds of vegegation and ground terrain, are difficult to detect using differences in average gray level or location of target edges alone., in French.

A rugged CW CO2 2-mm-diameter laser tube has been developed and its performance analyzed. It has been found that the small-signal gain was optimum when the CO2 partial pressure in a CO2:Xe:He mixture amounted to about 15 torr with the peak value decreasing with the CO2 proportion. Replacement of part of the CO2 by CO resulted in a significant improvement of the laser efficiency. A power extraction of 0.18 W/cm has been achieved at 110 torr with a CO2:CO:Xe:He mixture of 10:20:4:66 in a 9.5-cm-long discharge. There are indications that a better extraction is possible in longer tubes. Use of a grating as one end mirror was sufficient to control the electric field orientation and led to a greater tuning range by limiting the number of oscillating lines. At the present stage, semi-sealed-off operation is possible with a filling period of about 300 hours. (Author), in French.

This report describes the circuits added and the modifications made to the circuits of a digital scan-converter designed and built at DREV for a Bofors infrared camera. These modifications were made to reduce the noise present in the infrared image and to facilitate the operation of the scan converter. An interface circuit between the scan converter and a digital magnetic tape recorder is also described. (Author), Text in French; abstract and references in English.

See also Rept. no. DREV-R-703/73, dated Dec 73, AD-919 948.

Text in French; abstract in English.

in French.

A method has been developed for the production of high energy blasting prills (HEBP) containing TNT/Al or TNT/RDX/Al; the average particle size of the prills is approximately 3 mm. Such HEBP explosives seem attractive for special military engineering applications because they are free-flowing, water resistant, have a long shelf life and can be used over a wide temperature range. The method consists of forming fluid droplets of a molten mixture of explosive at the tip of a small-diameter nozzle immersed in the top of a water column. After the droplets leave the nozzle, they solidify as they fall through the remainder of the column. To avoid building up static charges, the prills are made semi-conductive by coating them with a thin layer of graphite. Studies were first undertaken in the laboratory and then scaled up to a 44-cm diameter pilot-plant prilling column that can produce about 90 kg of prills per batch. Some 1000 kg of each of two different compositions were produced for determination of their cratering characteristics (in a separate study). (Author), in French.

This report describes the Mark Recorder developed at DREV to record laser weapon fire simulator hits on Polaroid film. This device eliminates the need for .22 calibre practice ranges for tank gunnery training exercises such as consistency-of-lay tests. The document gives the principles of operation and construction details of a development model which will enable industry to develop engineering models suitable for extensive user testing and evaluation. It is also intended as an operation and maintenance manual for the development model. (Author), Text in English: Abstract in French.

Text in French; abstract in English.

See also AD-B004 653.

Copolyester diols were prepared in the presence of tetraoctylene glycol titanate as catalyst at 160 - 230 deg C from epsilon-caprolactone and several comonomers such as Emery Empol diol or triol derivatives, epoxides, esters formed by the reaction of an anhydride and an epoxide, or obtained by the condensation of a diol and a diacide. Several of these copolyester diols are less viscous than polycaprolactones diols and are compatible with ester plasticizers. Some of these yielded polyester-polyurethane binders which were evaluated in solid propellants. (Author), Text in French; abstract in English.

A passive infrared intrusion alarm system was modified and evaluated for its effectiveness to detect the presence of an intruder in a restricted area. the system consisted of an optical head gathering the infrared radiation coming from surrounding objects and their background onto a pyroelectric detector by means of a rotating and spherical focussing mirrors. The optical head was connected to an electronic circuit which compared successive scans to detect any significant changes in the collected radiation., Text in French; abstract in English.

A supersonic purely chemical continuous wave HCl laser is described in which nonequilibrium concentrations of atomic chlorine are generated by the branch-chain reaction of NO with ClO2. The ClO2 is injected into a stream of NO in helium immediately upstream of the throat of a slit nozzle. The reacting gases then expand as a free-jet into a low-pressure region where HI is added to rapidly form vibrationally excited HCl. The maximum HCl multiline output power of 35 W obtained represents a chemical efficiency of approximately 4.5% based on the total exothermicity of the pumping reaction and the limiting flow rate of HI. (Author), Summary in French.

Thin flexible sheets of pyrotechnic composition have been developed. The polymer-based composite formulation produces a white smoke, is self-adhesive when partly cured and remains flexible when completely cured. Formulations, their processing, the mechanical properties and behavior on aging are discussed. (Author), Text in French; abstract in English.

Target tracking by area correlation involves matching a stored reference image of the target to live search scenery. The performance of the area correlator can be severely degraded by target magnification and three-axis rotation. This report presents 2 algorithms that estimate magnification and rotation angles, and allow the tracker to take compensating action via zoom lens and roll gimbal. The first algorithm, applicable to fixed targets, estimates rotation about the line of sight only (roll angle). The second algorithm estimates rotation in 3 axes, as required for maneuvering targets. The presentation of both algorithms is supported by simulation using photographs and artificial images. (Author), in French.

Area correlation techniques are applied to the long-range remotely piloted vehicle (RPV) attack mission in both mid-course and terminal guidance phases. The mid-course guidance consists of a set of navigation fixes at waypoints along a preprogrammed route. The terminal guidance for weapon delivery incorporates a technique of compensation for magnification during range closure via a zoom lens. This report also presents simulations of both phases of guidance, using the sequential similarity detection algorithm as the image correlator. (Author), in French.

The variation of the infrared aerosol extinction coefficient as a function of relative humidity is studied. This is based on a two component particle distribution model. The aerosol extinction coefficient increases by a factor of more than 10 throughout the 3-5 and 8-15 micrometers spectral regions as the relative humidity increases from 0.5 to 0.99. For high relative humidities, a region of lower extinction around 10-11 micrometers is noticed. (Author), in French.

A programmer for the Intel 2708/2704, ultraviolet erasable and electrically reprogrammable read-only memory (EPROM) has been designed and built at DREV. Data to be programmed are fed into a general-purpose computer and then transferred to the programmer by means of a telephone line. The programmer is designed around a microcomputer system based on an Intel 8080 microprocessor in which all the operations are controlled by a program stored in a read-only memory. This type of design allows easy adaptation of the programmer for programming new EPROMs by simply changing the program of the microprocessor. (Author), Resume in French.

This report describes a thermal imaging system consisting of an IR camera, a digital scan converter, an X-Y display monitor and a digital tape recorder. The system can be used for recording and studying IR images in the 3- to 5-micrometer and 8- to 14-micrometer wavelength bands. It can also be used as an interface system for computer processing of images. (Author), in French.

This report describes an improved version of an assembler and simulator being used to translate man-readable statements into machine understandable code. This program, written in FORTRAN, allows programming of the 8080 microprocessor in symbolic language as well as the use of labels for jump instructions while the simulator duplicates exactly the behavior of the microprocessor in real applications. It is also possible to simulate interrupts and print out intermediate results. This new version may be used on any computer with a FORTRAN compiler while the former APL version was slower by a factor of ten and limited to a computer with an APL interpreter. (Author), in French.

This document describes a high-repetition-rate TEA-CO2 laser system which operates in a closed loop and can produce an average output beam power in excess of 1.5 kW at 1 kHz. After a brief outline of the design concepts of this important installation, details are given of the various subsystems involved in the electrical excitation, circulation of gases and control of the optical cavity. Then follow operational characteristics and a description of the behavior of the multimodal beam of radiation. Despite some limitations due to deterioration of gases and thermally induced distortion of the output coupling window, this laser remains reliable and capable of operating continuously for relatively long periods of time. It is also a versatile tool, incorporating several features which make it safe to use. (Author), Text in French.