Improving on police radar: lasers, cameras, and advanced signal processing are poised to help isolate individual offenders on crowded highways

Article Abstract:

The traditional down-the-road Doppler radar used by many law enforcement agencies can be difficult to use and can produce inaccurate results. A number of options for improvement and replacement are being explored. One idea is to pair a video camera with Doppler radar to produce an instant witness to traffic violations. This system does not provide answers to Doppler's shortcomings, however. Across-the-road radar offers better traffic identification, but using such a system is more difficult than traditional radar. Both down-the-road and across-the-road lasers are being considered as alternatives to radar. One advantage to lasers is that drivers would not have access to laser detectors as they do to radar detectors. The major drawback to lasers is they cannot be used in the moving mode, which is preferred by many users. Some areas are considering hiring traffic monitoring services to catch speeders, instead of relying on police. In New York City, police have installed surveillance cameras at intersections where drivers frequently run red lights. The cameras record pictures of traffic violations.

Police protection, Usage, Equipment and supplies, Automobiles, Design and construction, Law enforcement, Product introduction, Radar, Radar systems, New Technique, Ground Traffic Control

---

Single-Frequency Semiconductor Lasers

Article Abstract:

The new single-frequency semiconductor laser diode operates in a single stable frequency, is no larger than a grain of salt, and will allow fiber-optic systems to transmit information at extremely high bit rates over very long distances. A major goal of research in the area is the installation of a transoceanic cable. Present fiber-optic systems are limited by attenuation of signal as well as modal and transverse dispersion. Single-frequency laser diodes must emit light in only the fundamental transverse mode and only in one longitudinal mode. The eleven major designs of single-frequency lasers fall into the categories of coupled-cavity, frequency-selective feedback, injection-locked, and geometry-controlled. Selecting the right design involves tradeoffs, and these are not clear at this time. Concurrent research is proceeding in high-power single-frequency lasers. Tables give test results of types of lasers. Diagrams illustrate the various laser designs and physics of semiconductor lasers while graphs explain laser performance.

Semiconductor devices, Electronic components, Laser communications systems, Optics, Semiconductor Device, Laser and Infrared Communication, Multimode Fibers

---

Technology '84: Communications

Article Abstract:

The individual user is seeing greater communications capacity at lower cost thanks to communications technology advances. The major advancement of 1983 was the rapid growth in use of fiber optic cables for long-distance communications, with systems in operation or being installed. Direct-broadcast satellite television services to the Northeastern United States and the commercial use of high- frequency Ku-band for satellite communications have seen much development. Satellite services are becoming accessible to small users. Computer communications are seeing improvement thanks to low-cost private branch exchanges and approval of the IEEE 802 local-area network standard. Fiber-optic systems under construction in the United States and the world are listed in tables. A diagram explains satellite frequency bands.

Telecommunications equipment, Communications satellites, Local area networks, LAN, Communications Equipment, PBX, Transmission Lines

Similar abstracts:

• Abstracts: Quality as a board game. Unions and quality professionals need to work together to avoid tragedy. Survival for quality and unions
• Abstracts: Research: the key to quality policies and procedures. Decision tree helps categorize quality costs. Implementing multivariate statistical process control using hotelling's T2 statistics
• Abstracts: In-town solar condos: one developer's plan book. Launching a career in solar: practical experience and proven resources to help teachers and students alike
• Abstracts: A step beyond the envelope house. Grand designs for big solar buildings. Denver: trendsetter in solar homes
• Abstracts: Microcomputer Implementation of Simulation Benchmarks in Heat-Transfer and Dynamic Process Analysis. MPR Announces MathStat - A New Microcomputer Statistical Analysis System

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.