Showing papers on "Collision avoidance published in 1972"

Integrated collision avoidance, dme, telemetry, and synchronization system

Abstract: A time-sharing cyclic time slot system in which DME range measuring functions, collision avoidance functions, clock synchronization functions and/or data telemetry functions are all combined into an integrated repeating time sharing cycle in a non-interfering manner to achieve either general navigation and traffic control, or else stationkeeping, by the orderly exchange of pulse signals between participating ground stations and/or aircraft, and in which the cost of the system is minimized by using already existing ground and/or airborne VORTAC/TACAN/VOR/DME equipment and tuning the airborne transmitters and receivers in an agile manner to the various frequencies assigned for the performance of the above functions.

A problem of collision avoidance

Abstract: Collision avoidance between two vehicles of constant speed with limited turning radii, moving in a horizontal plane is investigated. Collision avoidance is viewed as a game by assuming that the operator of one vehicle has perfect knowledge of the state of the other, whereas the operator of the second vehicle is unaware of any impending danger. The situation envisioned is that of an encounter between a commercial aircraft and a small light aircraft. This worse case situation is examined to determine the conditions under which the commercial aircraft should execute a collision avoidance maneuver. Three different zones of vulnerability are defined and the boundaries, or barriers, between these zones are determined for a typical aircraft encounter. A discussion of the methods used to obtain the results as well as some of the salient features associated with the resultant barriers is included.

Airborne collision avoidance and other applications of time/frequency

Abstract: Time/frequency technology provides a reliable aircraft collision avoidance system (CAS) that can operate in either synchronous or asynchronous modes. Precision time-ordered techniques of CAS provide both range and range-rate measurements in a one-way sense to all aircraft as well as ground stations within range of transmitted microwave signals. The cooperative system utilizes exact frequency references coupled with precise synchronization: control of frequency to 1 part in 108and time to less than 1 µs. In addition to performing specific functions of protecting aircraft, the time/frequency CAS provides a means for wide dissemination of submicrosecond timing. Flying clocks, which are an integral part of the airborne CAS, have been providing transcontinental and intercontinental transfer of time since 1964. CAS ground stations can serve as depositories of time and frequency derived from flying clocks, satellites, Loran-C and Omega navigation systems, or television transfer referenced to national and international time/frequency standards. Airborne relay of CAS time provides a ready means for local transfer of time to users that are not within line of sight to a ground station. Thus time and frequency can be disseminated for applications other than collision avoidance. In the process of developing the technology and originating CAS, new systems for communication, position determination, navigation, and vehicle surveillance evolved. Such systems can be structured to operate at high data rates, provide improved accuracy and use less RF spectrum than existing techniques.

Ship collision avoidance

Abstract: When considering the subject of ship collision avoidance many factors or principles must be included. Even with the proper use of modern navigational aids such as RADAR many collisions still occur and still others are avoided only through last second actions. This article reviews the principles of proper collision avoidance along with many of the common problems and errors associated with the use of RADAR. The use of automated plotting in heavy traffic is also discussed.

Reactions of Pilots to Warning Systems for Visual Collision Avoidance.

Abstract: : A series of six experiments was conducted that have application to the development of Pilot Warning Instruments (PWI). The experiments were concerned with the effect of warning rates on pilot performance, pilot response to imminent collision threats, the evaluaion of scanning patterns, the value of warning-only, the effect of relative motion on pilot performance, and the effect of PWI display sector size. The results of these experiments offer a variety of useful data in the area of visual collision avoidance. (Author)

Collision Avoidance Systems and the Rules of the Nautical Road

Abstract: The International Regulations for Prevention of Collisions at Sea (33 U.S.C. 1051), the Inland Rules (33 U.S.C. 154), the Pilot Rules, Great Lakes Rules, Western Rivers Rules and the Admiralty Court decisions which interpret them, form a real and complex system of constraints upon the mariner in the navigable waters of the United States and on the open sea. These Rules are law, both international and U.S., and are used by the Courts in the determination of liability in case of collision. Admiralty Court decisions have modified and clarified the Rules of the Road in many cases. They have also added to the difficulty of the watch officer on the bridge of a ship at sea who must know not only the Rules but the Court interpretations in order to comply with them. The nature of the constraints imposed by these Rules is examined as they apply to the information furnished to the mariner from marine radar and radar based collision avoidance systems. The rules which apply when the vessels are in sight of each other and when they are not are discussed. The information needed to comply with the rules in each case is compared to the information available from radar and collision avoidance systems. The informational short comings of these systems are identified and an ideal collision avoidance system to aid the mariner in maneuvering under the constraint of the Rules of the Road is described.

Collision avoidance and station keeping antenna system

Abstract: A method of applying a circularly symmetric antenna system to collision avoidance and station keeping with the ability to respond retrodirectively. Specifically, airborne or surface vehicles may employ a method which determines the relative bearing between the vehicles from a single interrogation of one vehicle by the other.

Collision avoidance at sea with special reference to radar and radio telephony

Abstract: Reviews the current Rules of the Road limitations on use of radar and highlights the necessity for new procedures using UHF communications to establish courses of action in sufficient time to avoid collision. Suggested changes in the rules are discussed which could provide improved collision avoidance measures with the emphasis on VHF radio to establish a positive and unambiguous course of action in conjunction with radar information.

Collision avoidance and the mariner

Abstract: In this paper a study is made of that area of marine traffic engineering which is concerned with collision avoidance, and within that area the sub-section in which human factors are involved. Collision avoidance at sea is mainly achieved by adherence to the rules for preventing collisions, by routing schemes for separating traffic in high density areas and, within certain port limits, by local rules and advisory services, or occasionally by direct control of ship movements. To these well defined factors may be added the mariner's accumulated experience and instinct for self-preservation which gives rise to such nebulous, but not negligible, entities as the ‘seaman's eye’ and the ‘navigator's sixth sense’.

A collision avoidance warning criterion for maneuvering aircraft

Abstract: the requirements for an advanced degree from the Georgia Institute of Technology, I agree that the Library of the Institute shall make it available for inspection and circulation in accordance with its regulations governing materials of this type. I agree that permission to copy from, or to publish from, this dissertation may be granted by the professor under whose direction it was written, or, in his absence, by the Dean of the Graduate Division when such copying or publication is solely for scholarly purposes and does not involve potential financial gain. It is understood that any copying from, or publication of, this dissertation which involves potential financial gain will not be allowed without written permission.