ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02542.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractARAPID AND ACCURATEsolution to the relative motion triangle is imperative if modern high‐speed ships are to operate safely at sea under all conditions. Marine radar of great range, accuracy and flexibility provides early warning of the existence of potential dangers to the new ships, but methods of evaluation of the information provided by radar has not kept place with the advancement of equipment design.The methods commonly taught in the various maritime schools for the solution of the relative motion triangle require transfer of the information provided by the radar to a maneuvering board, conversion of the relative motion line to relative speed and direction, and an ultimate solution for a safe course of action by the maneuvering ship based upon the solution of the speed vector triangle.Since the length of the relative motion line cannot be conveniently measured on the radar scope itself, even when a reflection plotter is provided, this procedure cannot be completed on the reflection plotter. The reflection plotter is now the primary method of plotting the relative motion line and due to this inability to solve the problem on the plotter, or to complete the solution on the maneuvering board in the time available, with the methods currently taught ashore, the ship's officers normally do not carry the solution any further than an extension of the relative motion line to determine the CPA (closest point of approach). Change of course is generally decided by estimate—which is another word for guesswork.The use of a distance vector triangle enables the radar navigator to obtain a rapid and accurate solution on the reflection plotter or on the maneuvering board, with the reflection plotter being the preferred method. All calculations are avoided, as the lengths of the vectors for own ship and target's true course and distance made are based on the time duration of relative movement, and own ship's distance may be precalculated for various plotting intervals.Since the solution is plotted at the location of the relative motion line, the positions of several ships may be plotted simultaneously, and when a new course or speed to avoid one ship is plotted, the effect of this action on the CPA of all other targets may be determined immediately. Errors and loss of time in reading off and transferring data, are avoided and the solution may be arrived almost instantaneously.The Keystone Method of solving the distance triangle has the advantages of simplicity, clarity, accuracy and speed of solution. No navigator plotting by this method has ever been involved in a collision. The inadequacy of the speed vector triangle system of plotting raises a presumption of unseaworthiness of ships relying on this system where collision results from a failure to plot.When all factors are weighed, it seems abundantly clear that a shift to the distance vector triangle plotting method should be made by the maritime indus

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02543.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02544.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02545.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractASHORT REVIEWof the present trend of automation is presented. This is followed by a discussion of the shortcomings and causes of improper evaluation in the adaption of new technological gains. The necessity of the computarization and integration of all data presented by adapted instruments is highly recommended.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02546.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02547.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02548.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02549.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractSEVERAL TYPESof errors, including those associated with navigation and projectile miss distance, have been considered as a class, called radial errors. The Weibull distribution is suggested as a descriptive model. No “theoretical foundation” is given—none may exist; however examples are presented which demonstrate the applicability of this fun

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02550.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractPOSITIONS OR DIRECTIONSin or on the deep oceans often cannot be determined with sufficient accuracy using ocean navigation systems now available. Present limitations on accuracy arise, in part, because of the lack of reliable marine reference systems, including permanent marine control points. Control points are needed of the type that permit such a high degree of accuracy in land positioning. The accuracy and reliability of marine navigation systems could be improved if variations from some known standard could be determined. This paper discusses a standard system that could be established, viz., a marine geodetic calibration range.Positional fixes made with present systems are sometimes a mile or more in error. These systems could be evaluated, calibrated, and compared using the suggested marine geodetic range as a standard. The systems could be adjusted to minimize errors, thereby improving their accuracy and reliability.In one possible form, a geodetically constructed calibration range could extend parallel to a portion of the U. S. continental shelf and seaward to about 1500 miles from shore. The range, based on a bottom‐referenced system tied to the U. S. land geodetic network, might consist of a network of lines or grids formed, for example, by three to six permanent, and three temporary, ocean‐bottom control points.In one configuration, identification of stations would be by acoustic signals tramsmitted by a set of three transponders on the sea bottom. Position on the ocean surface relative to the bottom transponders would be determined by solving a three‐dimensional intersection problem, as is done in land geodesy. The most important measurements would be the line distances between the control points. It would be possible to measure these distances using aircraft line‐crossing or satellite techniques. The final coordinates of the control points on the sea bottom could be determined (by applying geodetic adjustment procedures) only after distance measuremens were completed. The relative accuracy of the proposed calibration range would be equivalent to 1:200,000, or about ±50 feet along a 1500‐mile calibr

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02551.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY