摘要:

Abstractthe designof reduced state, Kalman filters for an ESGM/SINS (Electrostatically Supported Gyro Monitor/Ships Inertial Navigation System) are described. The first filter is for resetting the SINS with navigation data from the ESGM; the second is for resetting the ESGM with position data from an external source. In the first case considerable test data are available on which to model the Kalman filter, while in the second case the test data are extremely sparse. Two alternative designs are discussed in each case, and the best are utilized in an error analysis of the combined ESGM/SINS.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01204.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThis paper describesthe development, application, and results of a methodology for evaluating the accuracy of OMEGA Predicted Propagation Corrections (PPC's). An overview of the PPC computation process is presented including a discussion of the basic PPC and also the force fit local adjustment.To evaluate PPC accuracy, a computer program is used to compare the observed OMEGA phase with the predicted phase at each monitor station (where the predicted phase is obtained by applying the PPC at the monitor station to the nominal or charted phase at that same location). Evaluation results are presented in the form of root‐mean‐square phase errors at the monitor sites after application of both the unadjusted basic PPC's and the force fit locally adjusted PPC's. Force fit effectiveness is readily evaluated by comparing the two sets of results.The data used for this evaluation have been collected from OMEGA monitor stations located in various parts of the world and then edited and compiled as the OMEGA Master File. This file, which is briefly described in this paper, is used to determine phase error coefficients employed in generating the basic PPC's. The Master File data are also used to calculate force fit corrections to the PP

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01205.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Abstractthe opportunity tosignificantly improve radio navigation capability is discussed. The main issues concern the military requirement for exploiting this technical opportunity and of the several viable alternatives which should be pursued. The advantages of a satellite‐based system are analyzed and compared with other technical approaches. The paper suggests that a satellite‐based system offers enough potential capability and relatively low risk to justify a feasibility demonstration prog

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01206.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Abstracta review of existingVery Low Frequency and Low Frequency transmissions that can be used for navigation, position and location, tracking and rendezvous is given. This includes the USSR Loran–C system, the USSR Very Low Frequency navigational aid (VLF), the international Omega system, the U. S. Navy VLF communications system, and those transmissions employed in the international time dissemination network. The characteristics of these various systems are discussed in relation to various applications. The potential and limitations to accuracy of the various systems are presented.A number of applications are described. In particular, the use of retransmission techniques for positioning of remote objects and differential techniques for enhancing accuracy are discussed.A piece of equipment is described which has been designed to utilize signals transmitted by the various navigation systems and an intermix of these transmissions. The simultaneous use of two or more systems to remove ambiguity and determine absolute position is described. The paper concludes that the VLF and LF transmissions are compatible and should co‐exist and are not necessarily redundant.Several references are given which include descriptions of the various systems and studies that have been performed analyzing and comparing performa

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01207.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Abstractthis paperaddresses one of the alternatives being considered by U. S. Airlines as a replacement for Loran–A in the event this service is discontinued. Loran–C coverage exists over a large portion of the airline route structure and the current evaluations are aimed at determining the suitability of Loran–C for airline service. Of special interest is the performance of new low cost fully automatic cycle matching Loran–C receivers compared with existing envelope matching Loran–A/C

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01208.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Abstractthe capabilityof the radio navigation equipment available for the modern deck officer has long since been out distanced by his needs for a reliable, accurate worldwide system. This system would be expected to contribute to the efficiency of operation of the Maritime Industry afloat. This and other aspects of the problem are set forth in this paper.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01209.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Abstractthis paper discussesthe use of three or more DME range measurements to determine aircraft position. Analysis of data collected by a test system shows range measurement errors with two components; a bias component of typically four hundred feet and a noise component of about two hundred feet r.m.s. By estimating and removing most of the bias error and smoothing the noise, position estimates with one hundred feet circular error probable (C.E.P.) or better are produced. Application of the techniques to special purpose high accuracy navigation systems is discussed.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01210.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Abstractin the united states, Statute 14 USC 81 assigns responsibility for aids to navigation to the U. S. Coast Guard. Established aids provide the user with position determination capabilities—to avoid hazards, reach destination or to maintain a fixed location. The maritime environment is divided into thehigh seas, the coastal/confluence zone(CCZ), andthe harbor/harbor entrance zone(HHE). The major unsatisfied area is the coastal confluence zone and the Department of Transportation (DOT) has recommended that this zone be given priority consideration by providing it an adequate radionavigation aid system. Taking into account accuracy, coverage, operating experience, availability of equipment and cost, it has been proposed thatLoran–Cbe the designated system. A portion of the system is already in existence and will remain so for considerable time in response to Department of Defense (DOD) requirements. Installation of Loran–C to cover the entire Coastal Confluence Zone and the Great Lakes, will enable U. S. Government funding of the existing Loran–A System to be phased out in a reasonable length

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01211.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Abstractthe uncertaintyof the future of a suitable electronic position fixing system for small craft is reported. The importance of the small craft part of the maritime community is established. The six essential parameters of a suitable small craft electronic position fixing device are given. Five systems, Satellite, Inertial, Omega, Loran–C., and Loran–A are examined for their ability to satisfy these required parameters. Loran–A best meets the requirements, Loran–C is a close

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01212.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractWith the emphasisthe Microwave Landing System (MLS) is receiving in the literature, one must not lose sight of the fact that the Conventional Instrument Landing System (ILS) will be an operational system well into the 1980's. The ILS is not only used for Category I and Category II landings and flight tests, but is now utilized for Category III Landing Feasibility Studies. The FAA, recognizing the increasingly stringent requirements being placed on the ILS, has been conducting research and development programs designed to yield significant improvements in ILS capability.This paper describes the results of some of these programs. The latest configurations for the localizer, glide‐slope and their monitor are discussed as well as the effects of reflecting objects on or near the aerodrome and terrain.New localizer antenna arrays are being developed that limit the amount of stray radiation on the aerodrome and surrounding terrain. These new arrays yield improved course characteristics. Integral and wide aperture monitors have been developed that give a true analog of the signal in space.Glide‐slope antenna arrays are being developed that do not utilize image effects. Therefore, they are not as susceptable to environmental effects. Optimized image‐type arrays are under study to minimize the effects of shortened ground planes; and integral monitors have been developed to give increased monitoring reliability.Comprehensive programs to ascertain the effects of taxiing 747's and 707's on glide‐slope and localizer signals are being accomplished. Modeling, ray‐optics and classical electromagnetic techniques have been utilized for these studies and the major results are

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1974.tb01213.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY