Atmospheric refraction effects on baseline error in satellite laser ranging systems

Because of the mathematical complexities involved in exact analyses of baseline errors, it is not easy to isolate atmospheric refraction effects; however, by making certain simplifying assumptions about the ranging system geometry, relatively simple expressions can be derived which relate the baseline errors directly to the refraction errors. The results indicate that even in the absence of other errors, the baseline error for intercontinental baselines can be more than an order of magnitude larger than the refraction error

Analysis of short pulse laser altimetry data obtained over horizontal path

Recent pulsed measurements of atmospheric delay obtained by ranging to the more realistic targets including a simulated ocean target and an extended plate target are discussed. These measurements are used to estimate the expected timing accuracy of a correlation receiver system. The experimental work was conducted using a pulsed two color laser altimeter

Prospects for measuring coherent neutrino-nucleus elastic scattering at a stopped-pion neutrino source

Rates of coherent neutrino-nucleus elastic scattering at a high-intensity stopped-pion neutrino source in various detector materials (relevant for novel low-threshold detectors) are calculated. Sensitivity of a coherent neutrino-nucleus elastic scattering experiment to new physics is also explored.Comment: 9 pages, 14 figures; minor modifications for publicatio

Profile of oral health students over a ten year period and their practice intentions after graduation

Published: January 26, 2017Objective: Limited research has been published on oral health therapists, particularly Australian cohorts of Bachelor of Oral Health (BOH) students who will graduate as oral health therapists. Aside from selection criteria and sample characteristics of students from some institutions, little is known about factors influencing career choice and career aspirations and workplace intentions after graduation. This study describes the characteristics, career choice factors and career aspirations of first year students enrolled at the University of Adelaide between 2005 and 2014. Methods: All first year cohorts (2005-2014) completed a self-report questionnaire as part of coursework. Demographic data, socio-economic status, career choice influences and graduate aspirations were collected and analysed. Kruskal –Wallis Tests were conducted on each variable with the cohort years. Results: Completed questionnaires suitable for analyses were received from 269 students (response rate 86%). Most students were under 21 years, in their preferred program and attended non-government schools. Males entering the profession increased. Career choice factors reflected those of other studies. The desire to work in the public sector declined after the first year of graduation with most reporting the private sector the workplace of choice after five and ten years. The stated intention of pursuing an academic career did not change and most reported the possibility of undertaking future postgraduate study. Conclusion: Working conditions and lifestyle factors have become increasing important and a growing number of males are entering the profession. Monitoring profile variations between BOH student cohorts overtime is important for program selection, recruitment and labourforce planning. If the trend continues for BOH students wanting to ultimately work in the private sector, access to care could be affected for particular population groups.Suzanne Gardner, and Kaye Roberts-Thomso

Tafassasset: The Saga Continues

In this study, we compare data for two separate Tafassasset stones and supply new oxygen isotope data for our sample. We include a discussion of the debate surrounding the classification of Tafassasset and offer a hypothesis for its origin based upon new information

Information extraction and transmission techniques for spaceborne synthetic aperture radar images

Information extraction and transmission techniques for synthetic aperture radar (SAR) imagery were investigated. Four interrelated problems were addressed. An optimal tonal SAR image classification algorithm was developed and evaluated. A data compression technique was developed for SAR imagery which is simple and provides a 5:1 compression with acceptable image quality. An optimal textural edge detector was developed. Several SAR image enhancement algorithms have been proposed. The effectiveness of each algorithm was compared quantitatively

Adaptive filtering of radar images for autofocus applications

Autofocus techniques are being designed at the Jet Propulsion Laboratory to automatically choose the filter parameters (i.e., the focus) for the digital synthetic aperture radar correlator; currently, processing relies upon interaction with a human operator who uses his subjective assessment of the quality of the processed SAR data. Algorithms were devised applying image cross-correlation to aid in the choice of filter parameters, but this method also has its drawbacks in that the cross-correlation result may not be readily interpretable. Enhanced performance of the cross-correlation techniques of JPL was hypothesized given that the images to be cross-correlated were first filtered to improve the signal-to-noise ratio for the pair of scenes. The results of experiments are described and images are shown

Student leadership training as a stress reduction strategy at a South African university

The role of student leaders at tertiary institutions is common practice. Student leaders participation in both academic and residence leadership roles provides an opportunity for skills development and also a source of income. The multiplicity of roles that residence leaders fulfill have been reported to be a source of stress and dissatisfaction which has had a negative effect on their academic performance. A descriptive research design using a self-report cross-sectional approach was used. The population was student leaders from 19 residence halls at a South African tertiary institution (n=184). Psychometric properties of measures used were consistent with previous studies. Significant positive correlations between role overload and role stress as well as training and role satisfaction were established. A negative relationship was established between training and role satisfaction. These findings are consistent with previous studies that reported training as an important factor in determining student leader satisfaction. Key words: Role stress; role overload; student leadership; training; role satisfaction; performanc

Nonresonant Contributions in B->rho pi Decay

We consider nonresonant contributions in the Dalitz plot analysis of B->rho pi->pi^+ pi^- pi^0 decay and their potential impact on the extraction of the CKM parameter alpha. In particular, we examine the role of the heavy mesons B^* and B_0, via the process B->pi (B^*, B_0)->pi^+ pi^- pi^0, and their interference with resonant contributions in the rho-mass region. We discuss the inherent uncertainties and suggest that the effects may be substantially smaller than previously indicated.Comment: 15 pages, 3 figures; minor changes, version to appear in Phys. Rev.