摘要:

ABSTRACTA methodology to determine the required navigation performance (RNP) for aircraft precision approach and landing under instrument meteorological conditions (IMC) is described. The RNP in turn defines an aircraft containment surface about the nominal flight path, called a tunnel, which specifies the allowed approach and landing flight path limits. If the aircraft and its navigation system satisfy the RNP, then the aircraft will successfully traverse the tunnel, terminating in a safe landing. The tunnel is defined by four RNP parameters: accuracy, integrity, continuity, and availability.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1994.tb02320.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTVessel traffic services, referred to as VTS systems, are being used in many ports and waterways worldwide as a means to reduce operational and environmental risk in marine transportation. These objectives are achieved principally by providing information, rather than by following the aviation model of traffic control. Recent tanker accidents that caused major pollution incidents have precipitated public calls for expansion of VTS operations, including direct traffic control. This paper describes VTS operational concepts from the perspective of a former VTS director and provides a model for implementing VTS systems. It also examines the applicability and feasibility of passive and active measures that can be used by shore‐based traffic regulators to prevent marine incidents and accidents in varying operational situation

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1994.tb02321.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTAn interferometric GPS flight reference system (IGPS FRS) has been implemented and flight tested on a transport category aircraft. The underlying principle of operation is similar to that used for kinematic surveying, and is also referred to as differential carrier‐phase tracking. The objectives of the IGPS FRS include 0.1 m accuracy RMS (each axis); one or more updates per second; UTC time synchronization better than 0.1 ms; real‐time, all‐weather operation; and repeatable flight paths. The latter requirement calls for full aircraft integration and coupled flight.This paper discusses the IGPS FRS architecture, its principles of operation, the aircraft integration, and the initial static calibration and flight test performance results. These are the first reported results for an interferometric GPS flight reference/autoland system that resolves carrier‐phase ambiguities in flight while simultaneously providing high‐precision guidance to a transport category aircraft through direct coupling to its flight contro

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1994.tb02322.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTAttitude determination using GPS carrier phase has been applied successfully to aircraft in experiments by a number of researchers. In an effort to formally characterize its accuracy and bandwidth performance, a GPS attitude determination system was flight tested against an inertial navigation unit (INU). Based on completely separate physical principles, this testing provides an independent means of evaluating overall performance.For the flight experiments, a twin‐engine turboprop transport aircraft was outfitted with a specially designed attitude determination receiver. A strapdown ring laser gyro INU was operated in the main cabin as the independent reference. For system evaluation, a number of test maneuvers were executed, including pitch angles to ± 30 deg and bank angles to ± 60 deg. Performance in moderate turbulence was measured. The impact of structural flexure during aircraft maneuvering was evalua

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1994.tb02323.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTMany future weapons and weapon carriers are expected to have an avionics suite that includes an integrated INS/GPS set. This relatively inexpensive means of navigation motivates examination of whether very high accuracy (∼ 10 ft circular error probable [CEP]) may be obtainable using only this set of weapon avionics operating in either a relative or differential GPS mode. This paper presents several different weapon system concepts that exploit such a capability to attack both fixed and stationary (but mobile) targets. It also addresses the theory behind each concept that enables the high accuracy and discusses the assumptions relating to each technique.Concepts explained include the use of aircraft equipped with an INS/GPS/syn‐thetic aperture radar (SAR) avionics suite to perform a real‐time relative targeting function for weapon initialization. The importance of reasonable aircraft maneuvers to enhance observability and speed up the three‐dimensional (3‐D) targeting fire control solution is also addressed. Simulation results for several realistic scenarios are

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1994.tb02324.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTIt is conventionally assumed that Loran‐C receivers process only samples taken before the first skywave components arrive, 35–60 μs after the groundwave. This techniqe has significant limitations when implemented in receivers of finite bandwidth, which increase the rise times of the pulses and substantially reduce the amplitudes of the groundwave signals at the 30 μs point. For this reason, many current receivers take samples later in the pulse and so suffer skywave errors. This paper examines the consequences of this practice. It then proposes a new class of techniques to allow the onset of skywave signals to be detected so that the sampling point can be adjusted accordingly. Novel algorithms for distinguishing skywaves from the groundwave are presented. Their benefits, and the computing resources they require, are assessed. The paper includes theoretical analyses, simulations, and Monte Carlo experiments to demonstrate the performance of the techniques pro

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1994.tb02325.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY