论文标题
从Kodaikanal太阳能天文台扩展了黑子区域系列
Extending the Sunspot Area Series from Kodaikanal Solar Observatory
论文作者
论文摘要
Kodeikanal太阳能天文台（KOSO）拥有世界上最长，最统一的黑子观测记录之一，该记录跨越了一个世纪以上（1904-2017）。有趣的是，这些观察结果（最初记录在摄影板/胶片中）是在整个时间段内使用相同的设置进行的，这使得该数据独特，最适合长期太阳可变性研究。此数据的很大一部分是在1921 - 2011年之间的大量数字化，并在Mandal等人（2017年）中发表了包含检测到的黑子参数（例如，面积和位置）的目录（例如，面积和位置）。在本文中，我们通过在1904- 1921年至2011年2017年之间包括新的数据集来扩展早期的目录。为此，我们对这些新数据集进行数字化和校准，其中包括解决随机图像方向问题。我们通过将KOSO图像与皇家格林威治天文台的共同数据进行比较来解决此问题。随后，将半自动化的黑子检测和自动化的UMBRA检测算法实现在这些校准图像上，以检测黑子和Umbra。此外，在此目录更新期间，我们还通过重新校准“胭脂”板，填补了现有的Koso Sunspot目录（1921-2011）中的数据空白。该更新的黑子区域系列涵盖了将近115年（1904-2017），并将成为社区的独特来源，可以研究太阳的长期可变性
Kodaikanal Solar Observatory (KoSO) possesses one of world's longest and homogeneous records of sunspot observations that span more than a century (1904-2017). Interestingly, these observations (originally recorded in photographic plates/films) were taken with the same setup over this entire time period which makes this data unique and best suitable for long-term solar variability studies. A large part of this data, between 1921-2011, were digitized earlier and a catalog containing the detected sunspot parameters (e.g., area and location) was published in Mandal et al.(2017). In this article, we extend the earlier catalog by including new sets of data between 1904-1921 and 2011-2017. To this end, we digitize and calibrate these new datasets which include resolving the issue of random image orientation. We fix this by comparing the KoSO images with co-temporal data from Royal Greenwich Observatory. Following that, a semi-automated sunspot detection and automated umbra detection algorithm are implemented onto these calibrated images to detect sunspots and umbra. Additionally, during this catalog updation, we also filled data gaps in the existing KoSO sunspot catalog (1921-2011) by virtue of re-calibrating the 'rouge' plates. This updated sunspot area series covering nearly 115 years (1904-2017) are being made available to the community and will be a unique source to study the long term variability of the Sun
