404 research outputs found

    Measuring what matters: the positioning of students in feedback processes within national student satisfaction surveys

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    The increasing prominence of neoliberal agendas in international higher education has led to greater weight being ascribed to student satisfaction, and the national surveys through which students evaluate courses of study. In this article, we focus on the evaluation of feedback processes. Rather than the transmission of information from teacher to student, greater recognition of the fundamental role of the learner in seeking, generating, and using feedback information is evident in recent international literature. Through an analysis of the framing of survey items from 10 national student satisfaction surveys, we seek to question what conceptions or models of feedback are conveyed through survey items, and how such framing might shape perceptions and practice. Primarily, the surveys promote an outdated view of feedback as information transmitted from teacher to student in a timely and specific manner, largely ignoring the role of the student in learning through feedback processes. Widespread and meaningful change in the ways in which feedback is represented in research, policy, and practice requires a critical review of the positioning of students in artefacts such as evaluation surveys. We conclude with recommendations for practice by proposing amended survey items that are more consistent with contemporary theoretical conceptions of feedback

    Personal Pedagogical Systems: Core Beliefs, Foundational Knowledge, and Informal Theories of Teaching

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    This case study describes a personal pedagogical system that acts a guide for adult educators in their practice. The system reflects core beliefs (assumptions about truth or propriety), foundational knowledge (essential knowledge for effective teaching of adults) and an informal theory of teaching (a theory of what works and what doesn\u27t work), all of which interact dialectically. Implications for further research and practice are discussed

    Critical Reflection and Imaginative Engagement: Towards an Integrated Theory of Transformative Learning

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    Based on a review of the literature, we propose an integrated approach to transformative learning that recognizes the importance of both the rational and affective, as well as the personal and the social dimensions in fostering self-understanding

    Planetary Radio Interferometry and Doppler Experiment (PRIDE) Technique: a Test Case of the Mars Express Phobos Fly-by. 2. Doppler tracking: Formulation of observed and computed values, and noise budget

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    Context. Closed-loop Doppler data obtained by deep space tracking networks (e.g., NASA's DSN and ESA's Estrack) are routinely used for navigation and science applications. By "shadow tracking" the spacecraft signal, Earth-based radio telescopes involved in Planetary Radio Interferometry and Doppler Experiment (PRIDE) can provide open-loop Doppler tracking data when the dedicated deep space tracking facilities are operating in closed-loop mode only. Aims. We explain in detail the data processing pipeline, discuss the capabilities of the technique and its potential applications in planetary science. Methods. We provide the formulation of the observed and computed values of the Doppler data in PRIDE tracking of spacecraft, and demonstrate the quality of the results using as a test case an experiment with ESA's Mars Express spacecraft. Results. We find that the Doppler residuals and the corresponding noise budget of the open-loop Doppler detections obtained with the PRIDE stations are comparable to the closed-loop Doppler detections obtained with the dedicated deep space tracking facilities

    Tidally Heated Exomoons around ϵ\epsilon Eridani b: Observability and prospects for characterization

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    Exomoons are expected to orbit gas giant exoplanets just as moons orbit solar system planets. Tidal heating is present in solar system satellites and it can heat up their interior depending on their orbital and interior properties. We aim to identify a Tidally Heated Exomoon's (THEM) orbital parameter space that would make it observable in infrared wavelengths with MIRI/JWST around ϵ\epsilon Eridani b. We study the possible constraints on orbital eccentricity and interior properties that a successful THEM detection in infrared wavelengths can bring. We also investigate what exomoon properties need to be independently known in order to place these constraints. We use a coupled thermal-tidal model to find stable equilibrium points between the tidally produced heat and heat transported within a moon. For the latter, we consider a spherical and radially symmetric satellite with heat being transported via magma advection in a sub-layer of melt (asthenosphere) and convection in the lower mantle. We incorporate uncertainties in the interior and tidal model parameters to assess the fraction of simulated moons that would be observable with MIRI. We find that a 2RIo2 R_{Io} THEM orbiting ϵ\epsilon Eridani b with an eccentricity of 0.02, would need to have a semi-major axis of 4 planetary Roche-radii for 100% of the simulations to produce an observable moon. These values are comparable with the orbital properties of gas giant solar system satellites. We place similar constraints for eccentricities up to 0.1. We conclude that if the semi-major axis and radius of the moon are known (eg. with exomoon transits), tidal dissipation can constrain the orbital eccentricity and interior properties of the satellite, such as the presence of melt and the thickness of the melt containing sub-layer

    Combining astrometry and JUICE-Europa Clipper radio science to improve the ephemerides of the Galilean moons

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    Context. The upcoming JUICE and Europa Clipper missions targeting Jupiter s Galilean satellites will provide radio science tracking measurements of both spacecraft. Such data are expected to significantly help estimating the moons ephemerides and related dynamical parameters (e.g. tidal dissipation parameters). However, the two missions will yield an imbalanced dataset, with no flybys planned at Io, condensed over less than six years. Current ephemerides solutions for the Galilean moons, on the other hand, rely on ground-based astrometry collected over more than a century which, while being less accurate, bring very valuable constraints on the long-term dynamics of the system. Aims. An improved solution for the Galilean satellites complex dynamics could however be achieved by exploiting the existing synergies between these different observation sets. Methods. To quantify this, we merged simulated radio science data from both JUICE and Europa Clipper spacecraft with existing ground-based astrometric and radar observations, and performed the inversion in different configurations: either adding all available ground observations or individually assessing the contribution of different data subsets. Our discussion specifically focusses on the resulting formal uncertainties in the moons states, as well as Io s and Jupiter s tidal dissipation parameters. Results. Adding astrometry stabilises the moons state solution, especially beyond the missions timelines. It furthermore reduces the uncertainties in 1/Q (inverse of the tidal quality factor) by a factor two to four for Jupiter, and about 30- 35% for Io. Among all data types, classical astrometry data prior to 1960 proved particularly beneficial. Overall, we also show that ground observations of Io add the most to the solution, confirming that ground observations can fill the lack of radio science data for this specific moon. Conclusions. We obtained a noticeable solution improvement when making use of the complementarity between all different observation sets. The promising results obtained with simulations thus motivate future efforts to achieve a global solution from actual JUICE and Clipper radio science measurements

    Combining astrometry and JUICE -- Europa Clipper radio science to improve the ephemerides of the Galilean moons

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    The upcoming JUICE and Europa Clipper missions to Jupiter's Galilean satellites will provide radio science tracking measurements of both spacecraft. Such data are expected to significantly help estimating the moons' ephemerides and related dynamical parameters. However, the two missions will yield an imbalanced dataset, with no flybys planned at Io, condensed over less than six years. Current ephemerides' solutions for the Galilean moons, on the other hand, rely on ground-based astrometry collected over more than a century which, while being less accurate, bring very valuable constraints on the long-term dynamics of the system. An improved solution for the Galilean satellites' complex dynamics could however be achieved by exploiting the existing synergies between these different observation sets. To quantify this, we merged simulated JUICE and Clipper radio science data with existing ground-based astrometric and radar observations, and performed the inversion. Our study specifically focusses on the resulting formal uncertainties in the moons' states, as well as Io's and Jupiter's tidal dissipation parameters. Adding astrometry stabilises the moons' state solution, especially beyond the missions' timelines. It furthermore reduces the uncertainties in 1/Q1/Q (inverse of the tidal quality factor) by a factor two to four for Jupiter, and about 30-35\% for Io. Among all data types, classical astrometry data prior to 1960 proved particularly beneficial. We also show that ground observations of Io add the most to the solution, confirming that ground observations can fill the lack of radio science data for this specific moon. We obtained a noticeable solution improvement when exploiting the complementarity between all different observation sets. These promising simulation results thus motivate future efforts to achieve a global solution from actual JUICE and Clipper radio science data

    Spacecraft VLBI tracking to enhance stellar occultations astrometry of planetary satellites

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    Stellar occultations currently provide the most accurate ground-based measurements of the positions of natural satellites (down to a few kilometres for the Galilean moons). However, when using these observations in the calculation of satellite ephemerides, the uncertainty in the planetary ephemerides dominates the error budget of the occultation. We quantify the local refinement in the central planet's position achievable by performing Very Long Baseline Interferometry (VLBI) tracking of an in-system spacecraft temporally close to an occultation. We demonstrate the potential of using VLBI to enhance the science return of stellar occultations for satellite ephemerides. We identified the most promising observation and tracking opportunities offered by the Juno spacecraft around Jupiter as perfect test cases, for which we ran simulations of our VLBI experiment. VLBI tracking at Juno's perijove close to a stellar occultation locally (in time) reduces the uncertainty in Jupiter's angular position in the sky to 250-400 m. This represents up to an order of magnitude improvement with respect to current solutions and is lower than the stellar occultation error, thus allowing the moon ephemeris solution to fully benefit from the observation. Our simulations showed that the proposed tracking and observation experiment can efficiently use synergies between ground- and space-based observations to enhance the science return on both ends. The reduced error budget for stellar occultations indeed helps to improve the moons' ephemerides, which in turn benefit planetary missions and their science products, such as the recently launched JUICE and upcoming Europa Clipper missions
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