Research Article
Leveraging Synthetic Data for Star and Satellite Photometry
Kimmy Chang*
,
Alex Cabello,
Jeff Houchard,
Jonathan Zachary Gazak,
Justin Fletcher
Issue:
Volume 12, Issue 2, June 2024
Pages:
18-29
Received:
16 August 2024
Accepted:
4 September 2024
Published:
29 September 2024
Abstract: In the realm of Space Domain Awareness (SDA), precise photometric measurements are essential for applications such as stability analysis, shape recovery, and material studies of satellites. However, current methods that rely on manual data collection and analysis are not scalable to autonomous frameworks, which are increasingly necessary due to the growing congestion in space. This research presents an approach to automate photometric measurements within a network of telescopes operating in non-ideal conditions. Our work focuses on achieving reliable photometry in degraded weather conditions, where traditional methods might fail, leading to false detections and unnecessary follow-up efforts. We utilize the SatSim space scene simulator to generate synthetic data for training and testing photometry algorithms. These algorithms include both traditional aperture photometry and machine learning-based approaches. Our methodology employs dynamic segmentation techniques to optimize the detection of satellites and stars under various adverse conditions. The segmentation methods were evaluated for their robustness in different scenarios, with the Depth-First Search + Interquartile Range (DFS + IQR) approach showing the most promise. Through extensive experimentation, we demonstrate that our approach can achieve a photometric precision of approximately 10−1, even in adverse conditions. This represents a significant advancement in the field, as it enables more reliable satellite detection and tracking in real-world, non-photometric environments. Additionally, our ablation studies highlight the importance of balanced datasets in reducing error metrics, particularly for underrepresented satellite classes. This work contributes to the development of more effective autonomous SDA systems, capable of operating efficiently in a wide range of environmental conditions.
Abstract: In the realm of Space Domain Awareness (SDA), precise photometric measurements are essential for applications such as stability analysis, shape recovery, and material studies of satellites. However, current methods that rely on manual data collection and analysis are not scalable to autonomous frameworks, which are increasingly necessary due to the...
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Research Article
Comparison of Visual Acuity Outcomes of Phacoemulsification and Small Incision Cataract Surgery
Eghosasere Iyamu*,
Clinton Ifeanyi Okechukwu
Issue:
Volume 12, Issue 2, June 2024
Pages:
30-36
Received:
5 September 2024
Accepted:
23 September 2024
Published:
10 October 2024
DOI:
10.11648/j.ajop.20241202.12
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Abstract: Background. The visual outcomes of phacoemulsification (Phaco) and manual small incision cataract surgery (MSICS) have been extensively studied, with research indicating that both methods are highly effective in restoring vision. Purpose. This study was aimed at comparing the visual acuity outcomes of the two surgical techniques. Methods. A total of 90 participants were scheduled for cataract surgery at Adetula Opticals & Eye Clinic, Oshodi-Isolo, Lagos State, Nigeria, from June to August 2023. The participants were divided into two groups of 45, a group was scheduled for Phaco (0.92 ± 0.65; 6/60-6/36) and SICS (1.32 ± 0.81; 3/60) logMAR. Visual acuities (VAs) were measured pre- and postoperatively. Results. The difference in mean VA pre-op of -0.40 (95% confidence interval (CI): -0.096, -0.71) between the two techniques was statistically significant (p = 0.000). There was no significant difference in the logMAR VAs between the techniques post-operatively (p = 0.06), although the visual outcome with the two methods showed the tendency of a better VA (0.11± 0.17 [6/9 - 6/6]) as opposed to that of the other two techniques (0.22 ± 0.32; [6/12 - 6/9]). Conclusion. Both techniques have been refined to a point where they provide comparable long-term visual outcomes, making the choice of method dependent on specific patient needs, surgeon expertise, and available resources.
Abstract: Background. The visual outcomes of phacoemulsification (Phaco) and manual small incision cataract surgery (MSICS) have been extensively studied, with research indicating that both methods are highly effective in restoring vision. Purpose. This study was aimed at comparing the visual acuity outcomes of the two surgical techniques. Methods. A total o...
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