摘要:

AbstractThe purposeof this article is to describe the new tables, with the above title, which are shortly to be published by the U. S. Naval Oceanographic Office as H.O. Pub. No. 229.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01810.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01811.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

Abstracta technique is describedin which bottom‐moored sonar beacons are surveyed in absolute (e.g., geodetic) position coordinates. The shipboard equipment consists of a sonar transmitter/receiver and a celestially‐augmented inertial navigator. Errors in the survey are shown to depend upon errors in the sonar measurements along with the celestial observation error and inertial navigator dynamical errors. Maneuvers are described and navigator reset techniques are discussed which serve to minimize the overall survey error. The effect of repeated measurements is analyzed to indicate the role it plays in error reduct

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01812.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01813.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractOmega is a verylong‐range VLF navigation system generating hyperbolic lines‐of‐position by phase difference measurements. Omega system applications described herein are based on results obtained from transmissions on the primary frequency of 10.2 kHz. Equivalent results with lane identification will be available through use of other frequencies in the multi‐signal format; 13.6 and 11.333 kHz. Results from the experimental system have demonstrated an absolute rms accuracy of one‐half to one mile in areas of good geometry and a relative accuracy for at‐sea station keeping of one‐third mile, or less. A system consisting of eight suitably sited stations is expected to yield the same absolute accuracy and a relative accuracy of the order of 200 yards (within 100‐mile range; area 20,000 square‐mile) over the entire surface of the earth. This paper describes applications of Omega to areas where other navigation systems would be nonexistent for positioning of inst

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01814.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01815.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01816.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01817.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractAcoustic transpondersprovide a particularly appropriate means for navigating relative to the deep sea floor. Their successful use, however, is dependent on solution of certain engineering problems and on understanding of the sound propagation situation in which the equipment is to be used. During the past year we have developed, built and used a set of appropriate, inexpensive transponders. These allow for selective calling of any one of three units (using pulses at 10.0, 10.5 or 11.0 kc) all of which reply at 12.0 kc. The design lifetime is 106pulses delivered over a period of up to one year. They have been built primarily to provide tracking information for a deeply towed, unmanned vehicle used for echo sounding and magnetometer observations. With this system useful responses have been obtained to ranges of 8 nautical miles. In normal operation the useful range is limited by the shadow zone formed by upward refraction of the acoustic energy near the sea floor. Use at sea has shown that these elements can provide effective navigational information and has allowed direct observation of the shadowing effects as the principal range limiting factor.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01818.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractPossible methodsfor the advance detection and warning of clear air turbulence by airborne devices are surveyed briefly. These include: active use of radar, microwaves, infrared and visible portions of the electromagnetic spectrum; passive use of infrared, millimeter waves and visible light; air temperature probes; electric field measurements; electric charging of aircraft; ozone detection; and microbarometric measurements. The state of the art of CAT detection and warning is still exploratory. No method has yet been demonstrated to give advance warning of CAT with a confidence level sufficient to justify operational use, and too little is known about the physical parameters of CAT to enable any one method of detection and warning to be singled out as the most promising. More basic research on the physics and meteorology of CAT itself is needed.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1966.tb01819.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY