摘要:

Abstracta navigation systembased upon the Navy's low‐drift, high‐precision, Electrically Suspended Gyros has been demonstrated to have surprisingly low error over long periods of time.By taking full advantage of this experience and other recent advances in the electronics art, a new, all‐weather, non‐radiating, automatic system is now possible. The system will operate at all latitudes and is independent of shore stations. Infrequent manual, celestial resets will serve to update or confirm the self‐contained system's position, velocity and heading information. The equipment is being planned to meet the anticipated needs for extremely high precision position finding in future naval and commercial marine operations.Basically, local gravity vertical (from accelerometers in a Schuler loop) is referred continuously to the celestial coordinate system. Coordinates are represented between celestial sightings by a pair of electrically suspended gyros. All data inputs are digital and are recorded at high sampling rates by a general purpose computer which smoothes data to reduce random errors. Similar smoothing is applied to the occasional celestial tracking inputs. Semi‐automated manual “sextants” are remotely read out by the computer to obtain hundreds of simultaneous, two‐body fixes per second; this permits, in effect, the averaging of thousands of sightings within a few minutes of “tracking” for position, velocity and heading resets to the computer.The computer not only yields position, but calculates vector velocity (ground speed and course), present true heading, steering order to maintain great circle course to destination, distance to go and expected arrival time at present speed. Observation of drifts is possible by comparing average, past heading to distance made good over a period of minutes or hours. Steering orders can be modified to

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1964.tb02110.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Abstractan extensive operational, engineering design, and experimental study is reported which has sought to determine the technical and economic feasibility of a satellite position determination system that very nearly satisfies the entirety of the needs of the community of potential users. These include geodetic and oceanographic surveys, maritime and airborne navigation operations, and terrestrial tracking net calibration and mapping for global test range instrumentation and space vehicle command control needs. Eventual need for other satellite navigation systems, which otherwise would mitigate against a limited applicability system because of the parallel implementation costs, would thereby be eliminated.Technical and general systems considerations discussed herein include satellite feasibility, receiver‐data processing, and subsystem configuration and performance. The most significant factors are seen to be user equipment cost and the uniform provision of precision in position determination at other than premium prices.The analysis has led to the evolution of a system concept which utilizes existent radar tracking installations in conjunction with a corner reflector equipped satellite that orbits at approximately 1,000 nm. It has been determined that the extremely accurate orbit determination resulting from system operation in the geodetic/ground tracking network calibration modes permits the configuration of a doppler navigation and survey system of pronounced simplicity and precision. Acting as a communication relay, the satellite would receive its position coordinates from the tracking network and, together with reference fixed frequency signals for doppler navigation purposes, retransmit them omni‐directionally on a programmed basis. Computer aided system simulation studies have established that the navigator's equipment, whose cost could be commensurate with that of conventional Loran receiver apparatus, could automatically provide absolute positional estimates to within about 100 ft. Preliminary design studies have shown that the navigator's equipment, which would be passive could, by the application of conventional circuitry miniaturization methods, occupy a volume of approximately one‐half cubic foot and, exclusive of the power source, weigh eight pounds. Optional position and status reporting could be provided for safety and traffic‐handling p

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1964.tb02111.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Abstractthe concept, hypothetical performance and potential uses of a position‐fixing system applicable to both surface ships and objects and to air and space vehicles are presented. This system concept has been named LOCATES, for Location of Air Traffic Enroute by Satellite. Three spherical surfaces of position, each containing the vehicle whose position is unknown, are established. Two of these are formed by simultaneously measuring the range from each of two stationary satellites (with known position) to the vehicle in question. The third is formed by knowledge of the vehicle altitude and its general geographic location; these may be known beforehand, as with ships, or may be measured on the vehicle and transmitted to a central computing facility, as with aircraft. The intersection of these three surfaces uniquely establishes the required position, except for one easily resolved ambiguit

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1964.tb02112.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1964.tb02113.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Abstractcubic's proposed approachto the problem of determining the coordinates of ships and/or aircraft at such locations as mid‐ocean is described. Determination of coordinates by a unified system to two different orders of accuracy is contemplated. The lower accuracies would apply to general navigation, en‐route traffic control, air‐sea rescue, and the like. The higher accuracies would permit the use of ships and/or aircraft as missile/space‐vehicle tracking sites.The basic system concept is described and explained. A number of possible system configurations is discussed. All these system configurations involve the use of the SECOR System techniques developed at Cubic. Certain of the possible configurations also involve the use of Cubic's vehicle‐borne phase‐comparison angle measurement techniques: these system configurations would be capable of a complete coordinate determination from a single satellite position, rather than from multipl

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1964.tb02114.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Abstractthe cruise of theR.V. ATLANTIS II to the Indian Ocean in 1963 presented an opportunity to attempt long‐range navigation from the very low frequency (VLF) transmissions of stabilized stations. With a precision oscillator and three phase tracking receivers on board the ship, horizontal movement from known points were indicated as phase differences which were computed to geographical locations, providing relative navigation. Positions were plotted from great circle computations and on a special VLF 30 series of Charts of the Southwestern Indian Ocean provided by the U. S. Navy Oceanographic Office.The relative navigational system was assembled from commercial components at a relatively low cost. Of particular interest to the oceanographer is the long‐range navigational capability, the ability to measure the drift of the ship while making hydrographic or current stations, and the inherent precise timing produced by the equipment. This work was supported by the Office of Naval Resea

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1964.tb02115.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1964.tb02116.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY