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

Urban and regional land use analysis: CARETS and census cities experiment package

The author has identified the following significant results. Successful tentative calibration permits computer programs to be written to convert Skylab thermal tapes into line-printed graymaps showing actual surface radiation temperature distributions at the time of imaging. The calibrations will be further checked when atmospheric soundings are available. Success of Skylab calibration suggests that satellite are feasible platforms for thermal scanning and provide a much broader geographical field of view than is possible with airborne platforms

Book Reviews

Reviews of the following books: Changes in the Land: Indians, Colonists, and the Ecology of New Englandby William Cronon; The Transformation of Political Culture: Massachusetts Parties, 1790s-1840s by Ronald P. Formisan

The Role of Service-Learning and Mentoring in the Early Career Development of a Research Methodologist

Anxiety about statistics may impede new scholars from developing quantitative research skills and from sharing those skills in service-learning, internship, and work settings. Using an interpretive case study design with a convenience sample of one emerging student leader in a collaborative university-community service-learning research project, we explored the question “How did the career path of a quantitatively skilled researcher develop?” Data collected over a 3-and-a-half-year period included 7 semi-structured interviews with the student during her master’s and doctoral program and interviews with 3 mentors, 2 peers, and 2 community partners, as well as observations and documents. A constant comparison analysis method identified emerging themes: the role of mentors in building skills, building trust, and modeling risk taking. The results suggest strategies for increasing the number of new researchers who can bring quantitative research skills and career readiness to their respective fields

The Brimfield (?) and Paxton (?) Formations in Northeastern Connecticut

Guidebook for field trips in Connecticut: New England Intercollegiate Geological Conference 60th annual meeting, Yale University, New Haven, Connecticut, October 25-27, 1968: Trip F-