This study aimed to standardize the BVR CCD photometry system of the Gwangju Science High School Observatory. We have observed Landolt standard stars using the CDK14 telescope and the STX-16803 CCD camera and carried out the data reduction by Maxim DL. As a result, we estimated the atmospheric extinction coefficients using the observation on August 29 and 31, 2024. By a standardization procedure, we calculated instrumental magnitudes and color indices outside the atmosphere. The instrumental magnitudes of celestial objects measured on the ground by the atmospheric correction were successfully transformed into standard magnitudes, with the standardization conversion formulas provided as following equations.                         The observational analysis revealed that atmospheric extinction coefficients vary depending on the observing conditions and that extinction increases at short wavelength. Additionally, the B filter exhibited significant second-order extinction effects due to color indices, suggesting the necessity of applying second-order atmospheric extinction coefficients for precise observations. This study suggests that Gwangju Science High School Observatory can serve as reliable resources for both educational and research purposes. Furthermore, this study demonstrates the potential for producing high-precision photometric data that meet international standards, even at a secondary school-level observatory. These findings are expected to contribute significantly to future astronomical education and research.

In this study, quantitative analysis is attempted on data collected from Chilgapsan Observatory Star Park in Cheongyang-gun, Chungcheongnam-do. The aim of this experimental study in which quantitative analysis of the Astronomical Science Museum in Korea is conducted is to investigate its current situation and secure basic data. As of July 31, 2023, it has had 283,931 cumulative visitors in total. It had the largest number of visitors when it opened (2009 year), after which their number reduced steadily until the pandemic (COVID-19, 2020–2022). Recently, however, the number of visitors has increased. Generally, the number of visitors is highest in August (20.8$\%$) and least in April (4.1$\%$). The visit rate is higher on weekends (Saturday and Sunday) than on weekdays (Monday–Friday), and groups comprise only about 5.3$\%$ of the total number of visitors. Moreover, it can be confirmed that the number of visitors increases sharply during events. Finally, it was confirmed that the visit rate was unaffected by weather conditions. Considering these results, we propose the following strategies: 1) Establish a special program that reflects “the weekend effect.” 2) Prepare a plan to attract group visitors during the weekdays using “the event effect.” 3) Arrange alternative programs (e.g., experiential activities) that can be conducted indoors regardless of weather conditions. We think that our findings will help establish a roadmap for the direction the Astronomical Science Museum should take and aid in preparing a strategic foundation to preemptively respond to unexpected situations (e.g., pandemics).

The Seoul Radio Astronomy Observatory (SRAO) operates a 6.1-meter radio telescope on the Gwanak campus of Seoul National University. We present the efforts to reform SRAO to a Very Long Baseline Interferometry (VLBI) station, motivated by recent achievements by millimeter interferometer networks such as Event Horizon Telescope, East Asia VLBI Network, and Korean VLBI Network (KVN). For this goal, we installed a receiver that had been used in the Combined Array for Research in Millimeterwave Astronomy and a digital backend, including an H-maser clock. The existing hardware and software were also revised, which had been dedicated only to single-dish operations. After several years of preparations and test observations in 1 and 3-millimeter bands, a fringe was successfully detected toward 3C 84 in 86 GHz in June 2022 for a baseline between SRAO and KVN Ulsan station separated by 300 km. Thanks to the dual frequency operation of the receiver, the VLBI observations will soon be extended to the 1 mm band and verify the frequency phase referencing technique between 1 and 3-millimeter bands.

대한민국 기상청에서 사용하고 있는 UM (Unified Model, UM) 모델의 국지예측시스템(Local Data Assimilation and Prediction System, LDAPS)은 수치모델 모의 시 대기경계층 유형에 따라 물리과정을 다르게 계산하기 때문에 이 과정을 검증하는 것은 모델의 정확도 향상에 중요하다. 따라서, 본 연구에서는 수치모델의 대기경계층 유형을 관측자료 를 기반으로 검증하였다. 관측자료를 기반으로 대기경계층 유형을 분류하기 위해서 보성 표준기상관측소에서 수행한 여름철 집중관측자료(라디오존데, 플럭스관측장비, 도플러 라이다, 운고계)를 활용하였으며, 2019년 6월 18일 부터 8월 17일 까지 61일 동안에 총 201회의 관측자료를 분석하였다. 또한 관측자료와 수치모델 결과가 다른 경우를 보면, 관측자료를 기반으로 한 대기경계층 유형 분류 결과에서 2유형으로 분류되는 사례가 수치모델에서는 1유형으로 분류된 사례가 53회로 가장 많이 나타났다. 그 다음으로는 관측자료를 기반으로 한 대기경계층 유형 분류 결과에서 5유형과 6유형 으로 분류되는 사례가 수치모델에서는 3유형으로 분류된 사례가 많이 나타났다(각각 24회, 15회). 관측결과와 수치모델 모의 결과가 일치하지 않은 사례는 모두 층적운 접합 여부 및 적운 모의 등 수치모델의 구름물리 부분의 모의 성능에 기인하여 발생한 것이라고 분석된다. 따라서, 대기경계층 유형 분류의 구름물리과정의 모의 정확도를 개선하면 수치모델 성능이 향상 될 것으로 판단된다.