摘要:

Abstracta study of the historyof the technology of navigation proves as rewarding and interesting to todays Navigator or Instrumentation Engineer as it does to the historian. This paper presents a pictorial survey and description of celestial data acquisition instrumentation from earliest times to the present. Principle features of each instrument and it's place in relation to the navigational concepts of it's day are discussed.

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02134.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe design effortin sensor and helicopter systems for operation at sea will be wasted if the navigation component is unable to guide the system with precision. The degradation of probability of successful search becomes intolerable as the ratio of navigation error to sensor range grows to a sizable fraction. To achieve accuracies such as those required when underwater sensor ranges are short requires a pilot display showing the way to steer. Since the missions now assigned to the over‐water helicopter are of vital importance to the nation, it is hoped that this exposition of the problem will prompt an effort on the part of the navigation community to satisfy a critical wan

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02135.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02136.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractArecent shipboardtrue motion radar display is described. In addition to providing a large, bright picture on a television type screen, the display has electronic storage capability. True motion is provided by a new solid‐state computer which is described. Special operator controls permit rapid and accurate determination of target speed and course, thus improving the capabilities of the radar in collision avoidance and pilotin

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02137.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02138.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThis paper presentsseveral electronically steerable antenna techniques, which for frequencies from 1 to 35 gc, show promise for application to spacecraft‐to‐spacecraft communications. It is indicated that such antennas can be realistically designed to provide maximum antenna gain for given weight, maximum bandwidth, and the capability of illuminating only desired spacial areas. Moreover, by incorporating self‐tracking capability into the antenna, spacecraft stabilization requirements can be relaxed even to the extent that high gain inertialess antenna systems with omnidirectional response are possible, in the case of unstabilized vehicles.Selected beam forming techniques are presented, and it is shown that many steerable antenna designs are derived from these basic techniques. An examination of the circuitry required to implement the design is utilized to prove that the antenna is no longer solely an input or output to a given system but becomes now an inseparable part of the system. Basic problem areas of beam forming, self‐tracking, and scanning are outlined. Moreover, evidence is given to indicate that lightweight, low loss stripline componentry is presently available to construct real systems.Several promising techniques, namely, the retrodirective and the transdirective, are applied to spacecraft‐to‐spacecraft and venus‐spacecraft‐earth communication links. System parameters are listed which show that increased performance and flexibility

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02139.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02140.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThis paper discussesa solution to the boundary value problem for space trajectories which has been found to be easily mechanized. Specifically, when the initial time, initial position, terminal time, and terminal position have been prescribed for a space flight, a method for finding the initial velocity that satisfies these constraints is presented. Three examples are given. They are the boundary value problems associated with an artificial satellite, a lunar impact trajectory, and an interplanetary trajectory. For purposes of illustrating the method and to assess the quality of the results, the lunar impact trajectory investigated was a 1963 Ranger trajectory and the interplanetary orbit selected was a 1969 Mars fly‐by trajectory of the Mariner type. Each of the orbits was obtained through the courtesy of the Jet Propulsion Laboratory; however, it is to be emphasized that the ground rules adopted only permitted that the launch date, launch position, arrival date, and arrival position be known. The launch velocity was determined independentl

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02141.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02142.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0028-1522    

DOI:10.1002/j.2161-4296.1965.tb02143.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY