Robert C. Harney

Imaging and target detection with a heterodyne-reception optical radar

A mathematical system model for a compact heterodyne-reception infrared radar is developed. This model incorporates the statistical effects of propagation through atmospheric turbulence, target speckle and glint, and heterodyne-reception shot noise. It is used to find the image signal-to-noise ratio of a matched-filter envelope-detector receiver and the target detection probability of the optimum likelihood ratio processor. For realistic parameter values it is shown that turbulence-induced beam spreading and coherence loss may be neglected. Target speckle and atmospheric scintillation, however, present serious limitations on single-frame imaging and target-detection performance. Experimental turbulence strength measurements are reviewed, and selected results are used in sample performance calculations for a realistic infrared radar.

Interdicting a Nuclear-Weapons Project

A “proliferator” seeks to complete a first small batch of fission weapons as quickly as possible, whereas an “interdictor” wishes to delay that completion for as long as possible. We develop and solve a max-min model that identifies resource-limited interdiction actions that maximally delay completion time of the proliferators weapons project, given that the proliferator will observe any such actions and adjust his plans to minimize that time. The model incorporates a detailed project-management (critical path method) submodel, and standard optimization software solves the model in a few minutes on a personal computer. We exploit off-the-shelf project-management software to manage a database, control the optimization, and display results. Using a range of levels for interdiction effort, we analyze a published case study that models three alternate uranium-enrichment technologies. The task of “cascade loading” appears in all technologies and turns out to be an inherent fragility for the proliferator at all levels of interdiction effort. Such insights enable policy makers to quantify the effects of interdiction options at their disposal, be they diplomatic, economic, or military.

Raman spectroscopic investigations of sarcoplasmic reticulum membranes.

Raman spectra are presented for sarcoplasmic reticulum membranes. Interpretation of the 1000-1130 cm-1 region of the spectrum indicates that the sarcoplasmic reticulum membrane may be more fluid than erythrocyte membranes that have been examined by the I portion of the membrane spectrum with a strong 1658 cm-1 band characteristic of C=C stretching in hydrocarbon side chains exhibiting cis conformation. This band is unaltered in intensity and position in H2O and in 2H2O thus obscuring amide I protein conformation. Of particular interest is the appearance of strong, resonantly enhanced bands at 1160 and 1527 cm-1 attributable to membrane-associated carotenoids.

Anatomy of a Project to Produce a First Nuclear Weapon

We describe the industrial project that a “proliferator” would conduct to produce a first, small batch of nuclear weapons. From refining yellowcake ore to final weapons assembly, we highlight the projects tasks and their interactions. The proliferator can choose alternative production technologies that offer quicker completion, but at higher cost in terms of limited resources. The proliferator can also expedite his project by devoting more resources to critical tasks. From physics and chemistry, we determine raw material requirements. From industrial engineering and materials science, we convert these requirements into estimates of the time, manpower, energy, and money required to complete each task under normal and expedited conditions. Using generalized project-management analysis tools, we then estimate the earliest possible completion time of the project, assuming two different levels of resource availability. We also estimate the time required to complete a weapon if some of the projects steps can be skipped; for example, if the proliferator acquires stolen, highly enriched uranium metal.

Raman spectroscopic analysis of Dutch Belt rabbit erythrocyte ghosts

Abstract Dutch Belt rabbit erythrocyte ghosts have been examined by Raman spectroscopy. An unusually high signal-to-noise spectrum was obtained which enabled assessment of vibrations within 300 cm −1 of the exciting radiation. Assignment of the observed bands to specific vibrations yielded information concerning membrane fluidity, the conformations of the peptide backbones and disulfide bonds of membrane proteins, and the configurations of lipid unsaturated hydrocarbon side chains.

Coherent IR Radar Technology

For over 15 years Lincoln Laboratory has been engaged in developing coherent infrared radar systems and relevant technology. The first major program was the Firepond laser radar. This program was initiated in the late 1960’s and drew heavily on earlier CO2 laser and infrared detector research at Lincoln Laboratory. Primary emphasis of the program was on satellite tracking and identification. The most recent version of this system was completed several years ago and is still operational.1,2 In a subsequent section a description of the Firepond radar will be presented and its more important accomplishments will be summarized.

Laser prf considerations in differential absorption lidar applications

Laser pulse repetition frequency (prf) is a major factor in determining the performance of differential absorption lidar (DIAL) systems. The effects of laser prf on concentration measurement accuracy and maximum usable range are quantified. Heterodyne-detection (coherent) and direct-detection (noncoherent) as well as path-averaged and range-resolved DIAL systems are analyzed.

Compact Infrared Radar Technology

Recent developments in the field of tactical infrared radars are reviewed. Experimental studies of imaging properties, weather penetration, and MTI operation are presented. The status of technology developments in the areas of compact CO2 lasers, telescope design, and fabrication and utilization of heterodyne detector arrays is discussed.

INFORMATION-BASED APPROACH TO PERFORMANCE ESTIMATION AND REQUIREMENTS ALLOCATION IN MULTISENSOR FUSION FOR TARGET RECOGNITION

A novel methodology offering the potential for resolving two of the significant problems of implementing multisensor target recognition systems, i.e., the rational selection of a specific sensor suite and optimal allocation of requirements among sensors, is presented. Based on a sequence of conjectures (and their supporting arguments) concerning the relationship of extractable information content to recognition perfor- mance of a sensor system, a set of heuristics (essentially a reformulation of Johnsons criteria applicable to all sensor and data types) is devel- oped. An approach to quantifying the information content of sensor data is described. Coupling this approach with the widely accepted Johnsons criteria for target recognition capabilities results in a quantitative method for comparing the target recognition ability of diverse sensors (imagers, nonimagers, active, passive, electromagnetic, acoustic, etc.). Extension to describing the performance of multiple sensors is straightforward. The application of the technique to sensor selection and requirements allo- cation is discussed.

Hole-boring in clouds by high-intensity laser beams: theory

The physics of hole-boring in clouds and fogs by high-intensity ir laser beams is investigated in a zerothorder approximation. Simple analytical expressions are obtained which describe the phenomena of interest. Application of these expressions to various types of clouds and fogs yields order-of-magnitude estimates of the laser powers required to bore holes of a given size and quality. The power requirements for hole-boring through light ground fogs or thin overcasts are in excess of 100 kW, while hole-boring through thicker overcasts will require laser powers much in excess of 10 MW. Dispersal of ground fogs over an extended area will require laser powers in the 10(8)-10(9)-W range and thus may not be cost effective simply in terms of energy consumption.