摘要:

AbstractThe principal taskof the earth‐bound celestial navigator is to determine Ms position on earth with respect to observations of celestial bodies. This paper is intended to develop the mathematical relationships making possible celestial position determination; to present a convenient analogue device for viewing the relationships; and to briefly discuss operational technique

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02204.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.tb02205.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.tb02206.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Abstractin direct responseto navigational requirements of the yachting, fishing, and maritime community, the Coast and Geodetic Survey of the U. S. Environmental Science Services Administration is presently engaged in an intensive tidal current survey of the Long Island and Block Island Sound area. The survey is being conducted by the U. S. Coast and Geodetic Survey Ship MARMER. One hundred and sixty current stations will have been occupied by the MARMER when the three year survey is completed in 1967. From one to three meters, equally spaced in the water column, are being operated at most of the stations. New Richardson current meters are being used at 23 of the stations for 15‐and 29‐day series, while the older Roberts meters are being used at the remainder for 100 hours. The reference station, for prediction purposes, is The Race. The results of the survey will be used to extend the coverage and increase the effectiveness of the “Tidal Current Tables” and “Tidal Current Charts, Long Island Sound and Block Island Sound.” Of particular note is the “Supplement” to the “Tidal Current Tables”, containing the results of the 1965 field work, which was published and distributed especially for the 1

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02207.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Abstractthe main computationalrequirement for LORAN navigation systems is the transformation to geographic latitude and longitude of time difference measurements made by the LORAN receiver.It is desirable to maintain a computational accuracy of less than one second of arc to avoid degradation of the inherently attainable LORAN system accuracy. It is therefore necessary to take into account the effect of a non‐spherical earth (ellipticity correction) and variable velocity of propagation (secondary phase correction.)Incorporation of these corrections into the analysis results in two non‐linear equations in two unknowns.This paper presents a derivation and discussion of an explicit,noniterative, LORAN mechanization of very high accuracy (approximately one second of arc). The advantages of this explicit solution are as follows:1. No initial guess as to receiver position is required. This provides for a self‐sufficient LORAN system.2. Perfect computational repeatability is achieved.3. With the explicit solution, it is always possible to select the proper solution of the two possible solutions.4. The simple explicit equations lead to reduced computational time and memory storage requirements for the computer.This technique has been programmed on the RECOMP III Computer. It was tested for accuracy by comparison with the National Bureau of Standards computations [2] for the East Coast LORAN Net. Representative samples of the results are

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02208.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractThis paper concernsuse of a computational device by ships' navigation officers to improve the efficiency of celestial fix taking operations. The objectives are to reduce the demands placed on the officers' time by present manual computation procedures and to reduce the loss of night vision caused by exposure to high illumination levels.Computational procedures are defined for presetting the sextant and for determining a line of position from one sextant observation. Successive applications of the procedures for two or more sightings will provide a celestial fix. Data from the Nautical Almanac are entered into the computer by the operator via a keyboard at appropriate points in the computation sequence.A small electronic digital computer suitable for performing the necessary computations is described. Special wiring of the computer memory converts the computer from a general purpose calculation tool to a special purpose navigation device tailored to the needs of the navigation officer. However, capability is retained for using the computer in alternate modes for other shipboard functions when it is not in use for fix‐takin

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02209.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.tb02210.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.tb02211.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.tb02212.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Abstractresearch has beenconducted on various methods of lighting and marking of aircraft to enhance their conspicuity and to provide information to other aircraft concerning relative position and other knowledge pertaining to collision prevention.More recently, experiments have been performed concerning the possible relationship between visual illusions and mid‐air collisions and near misses. One device that was proposed as promising from the results of the earlier research, mainly altitude coding of the anti‐collision light, is planned to be investigated as a possible “illusion busting” te

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1967.tb02213.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY