摘要:

ABSTRACTThe first Space Shuttle rendezvous missions were accomplished in support of the successful Solar Maximum Mission satellite retrieval and repair (STS 41‐C), the retrieval and return of two communication satellites (STS 51‐A), and the rendezvous with the Syncom IV‐3 satellite (STS 51‐D). The rendezvous navigation system performance was as good as or better than predicted on all missions.The onboard rendezvous navigation system continuously maintains accurate estimates of the Orbiter and target state vectors during the rendezvous mission phase. These vectors are used onboard to target the maneuvers required to achieve the rendezvous. The navigation outputs are also required to aid the Orbiter tracking sensors in tracking the target and to provide essential navigation information to the crew on the relative navigation display.The onboard rendezvous navigation software package—its inputs, models, characteristics, and outputs—and the rendezvous navigation performance for flight 41‐C are summarized. Included is a description of the rendezvous profile showing the relative vehicle geometry and the locations of the navigation sensor tracking arcs and Orbiter maneuvers within the profile. The crew displays and controls and their interfaces with the navigation system are described. The tracking sensors are defined. The method for processing the sensor measurements to update the state vector is summarized. Also, capabilities built into the navigation software to handle contingency situations are discussed. Plots are included to illustrate expected navigation system performance and to demonstrate the actual navigation system performance as observed by the crew during the ST

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00905.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTAs the Global Positioning System (GPS) is maturing, potential enhancements and improvements to the system have been studied. One such potential enhancement is the ability of the GPS satellites to navigate in an autonomous mode, which would significantly reduce the Control Segment (CS) service requirements. Conceptual feasibility has been established recently and reported elsewhere. This paper addresses the implementation feasibility of autonomous navigation as applied to a Block II type of space vehicle. Operational issues affecting the CS and Space Segment (SS) are also addressed.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00906.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTNASA Ames Research Center conducted a nonreal‐time, Differential Global Positioning System (DGPS) flight‐test experiment using two coarse‐acquisition (C/ A) code GPS receivers. The data were recorded concurrently at a fixed site and on board the NASA SH‐3G test helicopter. The aircraft conducted several simulated mission operations, including terminal approach, while being tracked by radar and laser systems. After the flights, data recorded by the two GPS receivers and the trackers were analyzed to determine whether differential corrections could improve the navigation performance of the airborne GPS receiver. An airborne navigation error history was obtained by subtracting the reference “true” trajectory (derived from the tracking data) from the airborne GPS navigation solution. At the same time, differential GPS corrections were obtained by subtracting the ground‐station GPS navigation solution from the true (surveyed) location of the ground receiver. Filtering was used to separate receiver‐unique errors in the GPS data from the locally common (spatially correlated) GPS errors. The results show high correlation between airborne navigation errors and the differential corrections. The airborne navigation solution is shown to be much improved after the addition of the differential corrections. Efforts are continuing to develop a real‐time differential data link between the ground station

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00907.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00908.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTThis paper describes the design of Navigation Software implemented for the family of GPS User Equipment developed by Rockwell‐Collins for the USAF NAVSTAR GPS Phase IIB Program. The family consists of one channel, two channel and five channel sets. The goal of the software design was to maximize commonalty of software functions across the entire family while minimizing the modifications required for new applications.The one channel set is specifically targeted to the manpack/vehicular application, while the two and five channel sets are generic sets adaptable to many applications. Adaptation to a particular host vehicle requires modification of only an outer layer of software modules, leaving the core software—including the navigation function—intact.The one channel navigation function centers around an 8‐state Kalman filter processing measurements from one satellite every second. The navigation function of the two and five channel sets is common to both families at the object code level and centers around a 12‐state Kalman filter. This filter runs at 1 Hz in one of three basic modes, in conjunction with high iteration rate processing of host vehicle sensor data that enables the maintenance of a navigation solution close to real time. This solution is used to aid satellite signal acquisition and tracking and may be used by host vehicle subsystems.This paper also discusses certain special features such as adaptive process noise, under‐determined operation, and handling of INS resets. It concludes with a sample of performance data from in‐plant an

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00909.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTThe Aerial Profiling of Terrain System (APTS) has been developed by The Charles Stark Draper Laboratory for the United States Department of the Interior Geological Survey to provide terrain profiling and other survey data at current accuracy standards with substantial savings in time and field work. Designed to operate in a relatively small aircraft such as the deHavilland Twin Otter, the APTS incorporates a three‐gimbaled inertial platform to indicate the position of the aircraft in three coordinates. A two‐axis laser tracker mounted on a common base acquires and follows prelocated retroreflectors in sequence, thereby supplying range and pointing information to update the navigator from ground truth. A laser profiler provides terrain clearance measurements which are combined with the highly accurate position data from the postflight data reduction to obtain ground profiles. An onboard computer with appropriate peripheral devices serves as system controller and data logger while navigating the aircraft during data collection activities. A video system featuring a color camera boresighted to the laser profiler records the image below the aircraft during profiling.Performance evaluation and survey application flights during the past year have confirmed the ability of APTS to achieve its positional design goal of ± 15 cm in the vertical and ± 60 cm in the horizontal coordinates.The paper outlines the considerations leading to the system configuration, describes the design and fabrication of the hardware and delineates the development of the real‐time and postflight data reduction software. Performance evaluation testing and data are presented, together with planning and results of surveying application tests

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00910.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Book reviewed in this article:INTRODUCTORY NAVIGATION:AN OCEAN NAVIGATION EXERCISE: BERMUDA TO THE AZORESThomas M. StoutADVANCE PLANNING PAYS OFF:CELESTIAL NAVIGATION PLANNINGLeonard GrayHISTORICAL:THE VOYAGE OF GEORGE VANCOUVER 1791–1795, 4 Volumes Edited by W. Kaye La

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00911.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1985.tb00912.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY