Autonomous navigation accuracy using simulated horizon sensor and sun sensor observations

A relatively simple autonomous system which would use horizon crossing indicators, a sun sensor, a quartz oscillator, and a microprogrammed computer is discussed. The sensor combination is required only to effectively measure the angle between the centers of the Earth and the Sun. Simulations for a particular orbit indicate that 2 km r.m.s. orbit determination uncertainties may be expected from a system with 0.06 deg measurement uncertainty. A key finding is that knowledge of the satellite orbit plane orientation can be maintained to this level because of the annual motion of the Sun and the predictable effects of Earth oblateness. The basic system described can be updated periodically by transits of the Moon through the IR horizon crossing indicator fields of view

X-ray based extensometry

A totally new method of extensometry using an X-ray beam was proposed. The intent of the method is to provide a non-contacting technique that is immune to problems associated with density variations in gaseous environments that plague optical methods. X-rays are virtually unrefractable even by solids. The new method utilizes X-ray induced X-ray fluorescence or X-ray induced optical fluorescence of targets that have melting temperatures of over 3000 F. Many different variations of the basic approaches are possible. In the year completed, preliminary experiments were completed which strongly suggest that the method is feasible. The X-ray induced optical fluorescence method appears to be limited to temperatures below roughly 1600 F because of the overwhelming thermal optical radiation. The X-ray induced X-ray fluorescence scheme appears feasible up to very high temperatures. In this system there will be an unknown tradeoff between frequency response, cost, and accuracy. The exact tradeoff can only be estimated. It appears that for thermomechanical tests with cycle times on the order of minutes a very reasonable system may be feasible. The intended applications involve very high temperatures in both materials testing and monitoring component testing. Gas turbine engines, rocket engines, and hypersonic vehicles (NASP) all involve measurement needs that could partially be met by the proposed technology

Longwall shearer tracking system

A tracking system for measuring and recording the movements of a longwall shearer vehicle includes an optical tracking assembly carried at one end of a desired vehicle path and a retroreflector assembly carried by the vehicle. Continuous horizontal and vertical light beams are alternately transmitted by means of a rotating Dove prism to the reflector assembly. A vertically reciprocating reflector interrupts the continuous light beams and converts these to discrete horizontal and vertical light beam images transmitted at spaced intervals along the path. A second rotating Dove prism rotates the vertical images to convert them to a second series of horizontal images while the first mentioned horizontal images are left unrotated and horizontal. The images are recorded on a film

A guide to computer-based training for the graphic arts industry

Industry in the United States is facing one of the greatest hurdles of all time, that of retraining its work force. The printing industry, in particular, faces a continuing lack of experienced and knowledgeable people. It has begun cooperative efforts to retrain workers in the basic skills needed to run a printing operation. Subjects like basic math, accounting, writing, and sciences round out the curriculum. Also on the scene are entrepreneurial training firms. Off-site training typically goes for $250-350 per person per day; the on-site instruction goes for$400 and up. And then there are options like computer-based tutorials. A firm in San Francisco ships an animated lesson on chokes and spreads to desktop publishers for $20. The demand for this packaging of instructional material has been high. But is it effective

ECONOMIC AND ENVIRONMENTAL IMPACTS OF NUTRIENT LOSS REDUCTIONS ON DAIRY AND DAIRY/POULTRY FARMS

Livestock Production/Industries,

The Media in Black and White

The media\u27s treatment of and interaction with race, like race itself is one of the most sensitive areas in American society. Whether in its coverage and treatment of racial matters or racial connections inside media organizations themselves, mass communication is deeply involved with race. The Media in Black and White brings together twenty journalists and scholars, of various racial backgrounds, to grapple with a controversial issue: the role that media industries, from advertising to newspapers to the information superhighway, play in helping Americans understand race

Radio—The Forgotten Medium

ASK ABOUT THE MEDIA and people think first of television, then newspapers. Sometimes, though not always, they acknowledge the existence of radio. But it is not uncommon for media critics to ignore radio altogether in their treatment of the larger modern media mix. Although the average American owns multiple radios and lives with this most portable medium in every room in the house, in the office, the car and even in parks, mountain retreats and at the beach, radio is rarely the topic of public discussion, giving it the dubious identity of the forgotten medium. This, the oldest of the broadcast media and once the king of electronic media, has moved farther and farther back in the media family photo. Occasionally there are references in the press to a radio station sale, a new radio network or a controversy first ignited on radio, but such sightings of radio in the public discourse are cameo appearances, like those of a once-famous leading actor reduced to walk-on or character roles. Radio, however, is much more than a bit player or an aging maiden aunt, as more than one author in this Journal suggest

The Fairness Factor

As THE FIRST POST-COLD WAR ADMINISTRATION takes office in Washington, there is general agreement that the media will play a significant role in its success or failure. Whether Americans wish President Clinton well or ill, they will all agree on at least one thing: that the media ought to be fair in reporting his efforts

I Don\u27t Want To Get Well

https://digitalcommons.library.umaine.edu/mmb-vp/2883/thumbnail.jp