摘要:

ABSTRACTResults from a flight test of a GPS carrier phase tracking receiver operated on a NASA Orion P‐3 aircraft are presented. The trajectory of the aircraft relative to a second, fixed receiver has been determined. The test was made over water, and the GPS vertical trajectory is compared to airborne LIDAR measured altitude data from the NASA Airborne Oceanographic LIDAR (AOL). The two data sets compare with a relative accuracy of 12 centimeters RMS, under poor GPS satellite geometry for vertical positioning. Analysis indicates that 1 to 2 centimeters relative vertical positioning is achievable with carrier phase tracking receivers and good GPS geometr

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1987.tb01487.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTThe first navigation sextant in the world was made by the London instrument maker, John Bird, in the year 1757. It, and four others by him are known to have survived, four of the five in museums in the United States, England,&Holland, and one in the possession of the author. Bird also published two booklets for the Board of Longitude on his methods of making and dividing the scales of astronomical instruments which contain brief reference to his sextants. These, taken with contemporary commentaries on his work, and newly discovered early documents, form the complete record on this major development in the history of navigation. The author has examined four of the five sextants in detail and has obtained data on the fifth. This is a comprehensive report on the historical aspects, mechanical design, and scale division of these instruments, together with the first set of photographs of all five ever published in one place.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1987.tb01488.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTPerhaps the most stringent requirement for land navigation is imposed by winter operations in the high arctic. The serious consequences of being lost or failing to find a supply dump in the arctic make reliability and accuracy vital necessities. A combination of circumstances conspire to also make the arctic a particularly difficult area in which to navigate by conventional means. Until GPS becomes fully operational, there will be no single system capable of continuously providing the necessary position and heading accuracy. Even then, reliability considerations will dictate that a self contained or autonomous backup be available, certainly for the military user. The Defence Research Establishment in Ottawa (DREO) has therefore developed a multi‐sensor, optimally integrated navigation system to satisfy the present operational requirements of the Canadian land forces, which are most severe in the arctic. This system, called PLANS (Primary Land Arctic Navigation System) was designed to be a highly reliable, high‐ to moderately‐accurate, automatic navigation system for all weather off‐the‐road use. Although designed primarily to meet an arctic requirement, PLANS would of course be just as applicable for desert navigation, or for any application in which reliability and accuracy are a priority, or where simpler and less costly methods are ineffective.PLANS combines several self contained sensors with two satellite receivers, using Kalman filter techniques to provide a continuous optimal estimate of position, height and heading. Time and attitude are also provided, along with waypointing functions. The self contained sensors consist of a gyrocompass/directional gyro unit, an odometer pickoff for speed, a magnetic fluxgate sensor (for which a detailed geomagnetic field model is used in the software) and a baroaltimeter. The satellite receivers are a single channel C/A‐code GPS and a dual channel Transit.This paper describes the requirement, the difficulties in meeting this requirement, the design of a multi‐sensor integrated system solution, some simulation results and some field

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1987.tb01489.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTSperry Marine, Inc. and Honeywell, Inc. are jointly developing a cost‐effective high performance marine ring laser inertial navigator (MARLIN). This navigator employs several accuracy enhancement techniques, including two‐axis indexing and two‐axis isolation control. Derivations and analysis results are presented which clearly demonstrate the advantages of these techniques in comparison to single‐axis indexing and other schemes.Key design aspects and current status of the MARLIN Navigator are described. A summary of at‐sea test data on a Honeywell demonstration system is presented, which confirms the MARLIN accur

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1987.tb01490.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

VESSEL TRAFFIC SYSTEMS: Captain Charles W. Koburger

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1987.tb01491.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1987.tb01492.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY