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Full-Text Articles in Aerospace Engineering
A Study Of Satellite Navigation, Dilution Of Precision, And Positioning Techniques For Use On And Around The Moon, John H. Macnicol
A Study Of Satellite Navigation, Dilution Of Precision, And Positioning Techniques For Use On And Around The Moon, John H. Macnicol
Theses and Dissertations
The National Aeronautics and Space Agency is examining several approaches to meet navigational requirements for spacecraft in lunar orbit, in transit to or from the moon, and for personnel on the lunar surface requiring an accurate, real-time, on-board navigation capability. This work addresses one possible solution to the navigation problem in the vicinity of the moon using a lunar satellite navigation system. Dilution of precision is the figure of merit used to determine if a candidate lunar satellite navigation system can meet accuracy specifications based on a given satellite constellation and the measurement types used. Ten satellite constellations, using two …
Broadcast Vs Precise Gps Ephemerides: A Historical Perspective, David L. M. Warren
Broadcast Vs Precise Gps Ephemerides: A Historical Perspective, David L. M. Warren
Theses and Dissertations
In most recent years, both high-resolution imagery systems and images were only available to military and national security organizations. Distinctive changes within the commercial image industry allowed space-borne pioneers to provide high-resolution images. Space-borne Image Company's Ikonos satellite provides a 1-meter resolution for the past 3 years. Current development of .5-meter resolution will be offered in the near future. Access of these images is available in ground stations located worldwide in different regions. Studies have shown that these high quality images are eye-catching and may serve a purpose through its design; on contrary high cost and accessibility does not met …
Ins Aiding By Tracking An Unknown Ground Object, Mursy Polat
Ins Aiding By Tracking An Unknown Ground Object, Mursy Polat
Theses and Dissertations
The reduction of the navigation error in an inertial navigation system by optically tracking a ground object is investigated. Multiple observations of the ground object are used. The location of the ground object is assumed unknown. A careful analysis of the measurement situation at hand reveals that by optically tracking an unknown ground object using passive, bearings-only measurements, the aircraft's angle of attack and sideslip angle can be measured. Thus, two new independent measurement equations featuring the aircraft's angular navigation variables are obtained. Hence, by optically tracking over time an unknown ground object, inertial navigation system aiding is in fact …