High-order aberration compensation with Multi-frame Blind Deconvolution and Phase Diversity image restoration techniques

Context. For accurately measuring intensities and determining magnetic field strengths of small-scale solar (magnetic) structure, knowledge of and compensation for the point spread function is crucial. For images recorded with the Swedish 1-meter Solar Telescope, restoration with Multi-Frame Blind Deconvolution and Joint Phase Diverse Speckle methods lead to remarkable improvements in image quality but granulation contrasts that are too low, indicating additional stray light. Aims. We propose a method to compensate for stray light from high-order atmospheric aberrations not included in MFBD and JPDS processing. Methods. To compensate for uncorrected aberrations, a reformulation of the image restoration process is proposed that allows the average effect of hundreds of high-order modes to be compensated for by relying on Kolmogorov statistics for these modes. The applicability of the method requires simultaneous measurements of Fried's parameter r0. The method is tested with simulations as well as real data and extended to include compensation for conventional stray light. Results. We find that only part of the reduction of granulation contrast in SST images is due to uncompensated high-order aberrations. The remainder is still unaccounted for and attributed to stray light from the atmosphere, the telescope with its re-imaging system and to various high-altitude seeing effects. Conclusions. We conclude that statistical compensation of high-order modes is a viable method to reduce the loss of contrast occurring when a limited number of aberrations is explicitly compensated for with MFBD and JPDS processing. We show that good such compensation is possible with only 10 recorded frames. The main limitation of the method is that already MFBD and JPDS processing introduces high-order compensation that, if not taken into account, can lead to over-compensation.Comment: in press in Astronomy & Astrophysic

Pesticide monitoring in inshore waters of the Great Barrier Reef using both time-integrated and event monitoring techniques (2013-2014)

The report details pesticide monitoring activities carried out utilising a combination of passive sampling and grab sampling techniques in the Great Barrier Reef Marine Park as part of the Reef Rescue Marine Monitoring Program (MMP). The MMP was implemented to evaluate changes in water quality in the Great Barrier Reef (GBR) and the status of key ecosystems under the Reef Water Quality Protection Plan (RWQPP) 2003 (which was further updated in 2009)

Best Practices for Retaining Public Speaking Students

This article draws on existing communication research and praxes to share the best practices for retaining students enrolled in the introductory public speaking course. Among the many important pedagogical practices that communication scholars have documented, this article highlights the value of 10 best practices: instructor use of immediacy and confirmation; instructor inclusion of written prescriptive feedback, peer feedback workshops, low-stakes assignments, applied assignments, and individual speech preparation tools; and instructor participation in out-of-class communication, online office hours, and classroom-connectedness

Pesticide monitoring in inshore waters of the Great Barrier Reef using both time-integrated and event monitoring techniques (2012-2013)

The report details pesticide monitoring activities carried out utilising a combination of passive sampling and grab sampling techniques in the Great Barrier Reef Marine Park as part of the Reef Rescue Marine Monitoring Program (MMP). The MMP was implemented to evaluate changes in water quality in the Great Barrier Reef (GBR) and the status of key ecosystems under the Reef Water Quality Protection Plan (RWQPP) 2003 (which was further updated in 2009).Report prepared by monitoring provider contractor to GBRMPA. Contract with gives GBRMPA complete use and distribution rights to all contract outputs, including this report

Marine Monitoring Program: Annual report for inshore pesticide monitoring 2014-2015

[Extract] Declining water quality influenced by land-based activities and run-off has been identified as a significant threat to the health and resilience of the Great Barrier Reef (the Reef). Sediment, nutrients and pesticides remain the key water quality issues and may have negative impacts on marine plants and animals (primarily corals and seagrass) that are exposed to run-off plumes in inshore marine areas. The Reef Water Quality Protection Plan (Reef Plan) is a collaborative program designed to improve the quality of water in the Reef though improved land management practises. In 2014-2015, Entox carried out water quality monitoring activities in the Great Barrier Reef Marine Park (the Marine Park) as part of the Marine Monitoring Program (MMP) under Reef Plan. The key objectives of the project are to monitor and assess trends in inshore water quality (i.e. concentrations of pesticides/ herbicides) against the Marine Park Water Quality Guidelines, and link inshore concentrations and their transport with end-of-catchment loads

Pesticide monitoring in inshore waters of the Great Barrier Reef using both time-integrated and event monitoring techniques (2010-2011)

The report details pesticide monitoring activities carried out utilising a combination of passive sampling and grab sampling techniques in the Great Barrier Reef Marine Park as part of the Reef Rescue Marine Monitoring Program (MMP). The MMP was implemented to evaluate changes in water quality in the Great Barrier Reef (GBR) and the status of key ecosystems under the Reef Water Quality Protection Plan (RWQPP) 2003 (which was further updated in 2009).ENTOX: National Research Centre for Environmental Toxicolog

Phase diversity restoration of sunspot images I. Relations between penumbral and photospheric features

We investigate the dynamics of and the relations between small-scale penumbral and photospheric features near the outer penumbral boundary: penumbral grains (PGs), dark penumbral fibrils, granules, and photospheric G-band bright points. The analysis is based on a 2 h time sequence of a sunspot close to disc center, taken simultaneously in the G-band and in the blue continuum at 450.7 nm. Observations were performed at the Swedish Vacuum Solar Telescope (La Palma) in July 1999. A total of 2564 images (46 arcsec x 75 arcsec) were corrected for telescope aberrations and turbulence perturbations by applying the inversion method of phase diversity. Our findings can by summarized as follows: (a) One third of the outward-moving PGs pass through the outer penumbral boundary and then either continue moving as small bright features or expand and develop into granules. (b) Former PGs and G-band bright points next to the spot reveal a different nature. The latter have not been identified as a continuation of PGs escaping from the penumbra. The G-band bright points are mostly born close to dark penumbral fibrils where the magnetic field is strong, whereas PGs stem from the less-magnetized penumbral component and evolve presumably to non-magnetic granules or small bright features.Comment: Accepted by A&A, 9 pages and 5 figure

Book Review Panel: When Souls Had Wings: Pre-mortal Existence in Western Thought

On October 13, 2011, BYU Studies sponsored a program reviewing Terryl Givens’s important Oxford book on the idea of the premortal existence of souls in various lines of Western philosophy and religion. Because this first volume of its kind covers literature from so many different civilizations, the editors of BYU Studies saw no way to do this book justice without involving a panel of reviewers from several disciplines. After portions of Robert Fuller’s forthcoming review in Church History were read, the program proceeded with reviews, responses, and open discussion