A Multi-Annotator Survey of Sub-km Craters on Mars

Francis, Alistair; Brown, Jonathan; Cameron, T. W. M.; Clarke, Reuben Crawford; Dodd, Romilly; Hurdle, Jennifer; Neave, Matthew J.; Nowakowska, Jasmine; Patel, Viran; Puttock, Arianne; Redmond, Oliver; Ruban, Aaron; Ruban, Damien; Savage, Meg; Vermeer, Wiggert; Whelan, Alice; Sidiropoulos, Panagiotis; Müller, Jan-Peter

doi:10.3390/data5030070

Cited by 7 publications

(3 citation statements)

References 24 publications

(28 reference statements)

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“…Here, we focus only on the DPR. This work was undertaken with the Orbyts program, which partners scientists with schools to support school students' involvement in research (Chubb, Joseph, et al., 2018 ; Chubb, Naumenko, et al., 2018 ; Darby‐Lewis et al., 2019 ; Edwards et al., 2020 ; Francis et al., 2020 ; French et al., 2020 ; Grafton‐Waters et al., 2021 ; Holdship et al., 2019 ; McKemmish et al., 2017 , 2018 ; Wibisono et al., 2020 ).…”

Section: Observationsmentioning

confidence: 99%

Jupiter's X‐Ray and UV Dark Polar Region

Dunn

Weigt

Grodent

et al. 2022

Geophysical Research Letters

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We present 14 simultaneous Chandra X‐ray Observatory (CXO)‐Hubble Space Telescope (HST) observations of Jupiter's Northern X‐ray and ultraviolet (UV) aurorae from 2016 to 2019. Despite the variety of dynamic UV and X‐ray auroral structures, one region is conspicuous by its persistent absence of emission: the dark polar region (DPR). Previous HST observations have shown that very little UV emission is produced by the DPR. We find that the DPR also produces very few X‐ray photons. For all 14 observations, the low level of X‐ray emission from the DPR is consistent (within 2‐standard deviations) with scattered solar emission and/or photons spread by Chandra's Point Spread Function from known X‐ray‐bright regions. We therefore conclude that for these 14 observations the DPR produced no statistically significant detectable X‐ray signature.

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Section: Observationsmentioning

confidence: 99%

Jupiter's X‐Ray and UV Dark Polar Region

Dunn

Weigt

Grodent

et al. 2022

Geophysical Research Letters

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“…ORBYTS spans a wide range of research areas, such as providing accurate molecular transition frequencies ((McKemmish et al 2017a((McKemmish et al , 2018Chubb et al 2018 ;Darby-Lewis et al 2019 )) and characterizing the transit parameters of a range of exoplanets (Edwards et al 2020(Edwards et al , 2021. Other projects have included analysing CH 3 OH and CH 3 CHO emission in protostellar outflows (Holdship et al 2019 ), applying of artificial intelligence to images (Francis et al 2020 ), Xray spectral analysis of active galactic nuclei (Grafton-Waters et al 2021 ), and planetary aurorae (Wibisono et al 2020 ).…”

Section: O R I G I Na L R E S E a R C H B Y Yo U N G T W I N K L E S ...mentioning

confidence: 99%

Quantifying the dust in SN 2012aw and iPTF14hls with ORBYTS

Niculescu-Duvaz

Barlow

Dunn

et al. 2022

Monthly Notices of the Royal Astronomical Society

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Core-collapse supernovae (CCSNe) are capable of producing large quantities of dust, with strong evidence that ejecta dust masses can grow significantly over extended periods of time. Red-blue asymmetries in the broad emission lines of CCSNe can be modelled using the Monte Carlo radiative transfer code damocles, to determine ejecta dust masses. To facilitate easier use of damocles, we present a Tkinter graphical user interface (GUI) running damocles. The GUI was tested by high school students through the Original Research By Young Twinkle Students (ORBYTS) programme, who used it to measure the dust masses formed at two epochs in Type IIP CCSNe SN 2012aw and iPTF14hls, demonstrating that a wide range of people can contribute to scientific advancement. Bayesian methods quantified uncertainties on our model parameters. From the red scattering wing in the day 1863 Hα profile of SN 2012aw, we constrained the dust composition to large (radius >0.1 μm) silicate grains, with a dust mass of $6.0^{+21.9}_{-3.6}\times 10^{-4}~M_\odot$. From the day 1158 Hα profile of SN 2012aw, we found a dust mass of $3.0^{+14}_{-2.5}\times 10^{-4}$ M⊙. For iPTF14hls, we found a day 1170 dust mass of 8.1 $^{+81}_{-7.6}\times 10^{-5}$ M⊙ for a dust composition consisting of 50 per cent amorphous carbon and 50 per cent astronomical silicate. At 1000 days post explosion, SN 2012aw and iPTF14hls have formed less dust than the peculiar Type II SN 1987A, suggesting that SN 1987A may have formed a larger dust mass than typical Type IIP’s.

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“…Lee and Hogan [29] proposed an automated CDA with humanlevel performance by multiple neural networks, but the method used not only DEM but also thermal infrared imagery, so the method did not have universal applicability. Francis et al [30] presented a dataset of craters for CDA based on deep learning. Cui et al [31] directly used the crater curve matching for the planetary landing navigation system and obtained superior accuracy.…”

Section: Introductionmentioning

confidence: 99%

Robust Crater Detection Algorithm Based on Maximum Entropy Threshold Segmentation

Ping

Deng

2022

International Journal of Aerospace Engineering

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For future lunar exploration and planetary missions, the digital elevation model (DEM) of the target object may not be well prepared before the mission, so developing a new robust crater detection algorithm (CDA) without prepared high-precision DEM is needed to meet the requirements of a high-reliability and high-precision detection and navigation system. In this paper, we presented a new robust lunar CDA method based on maximum entropy threshold segmentation. By calculating the entropy distribution of the ternary image, the threshold for retaining the maximum amount of image information is selected adaptively, a variety of evaluation indicators are proposed, and a multiple-indicator constraint matrix is constructed to realize the extraction and fitting of the craters. The proposed method has the following advantages: (1) it has strong robustness and is capable of extracting complete craters under multiple illumination conditions, which makes it suitable for the extraction of large-scale planetary and lunar images; (2) the extracted crater edges are clear and complete and do not merge with the surrounding environment edge; and (3) it avoids the problem of parameter sensitivity that is present in a traditional CDA algorithm. The proposed method was verified using an image taken by the Chang’e-2 lunar probe, and a comparison with the traditional method based on morphology and adaptive Canny edge detection shows that the number of craters detected increases by more than 35%, while the computational efficiency is improved by more than 40%.

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A Multi-Annotator Survey of Sub-km Craters on Mars

Cited by 7 publications

References 24 publications

Jupiter's X‐Ray and UV Dark Polar Region

Jupiter's X‐Ray and UV Dark Polar Region

Quantifying the dust in SN 2012aw and iPTF14hls with ORBYTS

Robust Crater Detection Algorithm Based on Maximum Entropy Threshold Segmentation

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