• 한국환경과학회지
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• 제11권10호
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• pp.1055-1060
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• 2002

A new method of automatic recording raingauge is developed to measure rainfall 1200mm full scale with high accuracy and resolution. The principle of new instrument is to detect a weight change of a buoyant weight according to a change in water level of raingauge measured by the use of a strain gauge load cell. This method has the advantage of increasing measurement accuracy, since no moving equipment is used. Laboratory test of the instrument was recorded 0.4% error of 190mm rainfall amount. The validity of new instrument was examined by comparing its measured values with values recorded by automatic weather station on June 24 to 25 2001 at Daegu Meteorological Station, when there is 148.3mm rainfall amount. In spite of much rainfall there is only 0.77mm difference of total rainfall amount. This instrument was accomplished high accuracy and resolution at field test in much rainy day.

• 대기
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• 제26권4호
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• pp.541-551
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• 2016

A real-time quality control algorithm for $PM_{10}$ concentration measured by Continuous Ambient Particulate Monitor (FH62C14, Thermo Fisher Scientific Inc.) has been developed. The quality control algorithm for $PM_{10}$ data consists of five main procedures. The first step is valid value check. The values should be within the acceptable range limit. Upper ($5,000{\mu}g\;m^{-3}$) and lower ($0{\mu}g\;m^{-3}$) values of instrument detectable limit have to be eliminated as being unrealistic. The second step is valid error check. Whenever unusual condition occurs, the instrument will save error code. Value having an error code is eliminated. The third step is persistence check. This step checks on a minimum required variability of data during a certain period. If the $PM_{10}$ data do not vary over the past 60 minutes by more than the specific limit ($0{\mu}g\;m^{-3}$) then the current 5-minute value fails the check. The fourth step is time continuity check, which is checked to eliminate gross outlier. The last step is spike check. The spikes in the time series are checked. The outlier detection is based on the double-difference time series, using the median. Flags indicating normal and abnormal are added to the raw data after quality control procedure. The quality control algorithm is applied to $PM_{10}$ data for Asian dust and non-Asian dust case at Seoul site and dataset for the period 2013~2014 at 26 sites in Korea.

• 대기
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• 제23권1호
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• pp.47-61
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• 2013

The Punggi (風旗) is one of the meteorological instruments made in the Joseon Dynasty (朝鮮王朝). Its purpose was to observe the direction of the wind. It is estimated that it started its operation in the $16^{th}$ century at least. But it does not remain in a perfect form, like the Chugugi (測雨器) and the Supyo (水標). The Punggi (風旗) can only be found at old document data, while the stone used to build the Punggi still remains. Since the stone had been named as the Punggi-dae (風旗臺) by 和田雄治 (1917), the name has not been changed until now. The Punggi is currently located in the Gyeongbok-gung (景福宮) and the Changgyeong-gung (昌慶宮). Meantime, there have been several transfers of its position. However, 和田雄治 (1917)'s paper and the "每日新報" (Maeil-Sinbo, 1929) articles have provided new clues. Also, the word 'Hupungso (候風所)' was found in the "朝鮮王朝實錄" (The annals of the Joseon Dynasty) and the "承政院日記" (Daily records of royal secretariat of Joseon dynasty). A designed harbor where the ship was staying was usually considered a special section for wind observations. It is assumed that the Hupungso was in most of the harbors at that time. This paper assumes the Punggi and the Hupungso had a lot of interest in wind observations in the Joseon Dynasty. In this study, we'll look for contained information about the Punggi and the viewpoints about wind during the Joseon Dynasty.

• 한국항행학회논문지
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• 제28권1호
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• pp.60-67
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• 2024

민간항공사고의 대부분은 인적요인에 의해 발생하고 특히 회전익 항공기는 예상하지 못하거나 의도하지 않게 악기상으로 진입하는 IIMC (instrument meteorological conditions) 상황에서의 사고가 많이 발생하고 있다. 이 연구는 저시정 조건에서 회전익 항공기 조종사의 에러율를 다각적으로 분석하여 비행특성에 관한 통찰력을 얻고 IIMC 상황에서의 사고를 줄이기 위한 방안을 연구하였다. 저시정 조건에서 조종사의 에러 발생율을 모션이 장착된 비행 시뮬레이터를 활용하였으며 65명의 조종사가 실험에 참여하였다. 실험을 통해 획득한 비행 데이터로 비행시정 감소, 공간정위상실 유무, 조종사 자격 등 다양한 조건에 따라 에러 발생율을 비교 분석하였다. 분석결과 다양한 조건에서 비행특성에 대한 특이점을 발견할 수 있었고 조종사의 자격 등급, 계기비행 (IFR; instrument flight rules) 자격 유무, 비행단계별 에러 발생율에 유의미한 차이가 발생하였다. 이와 같은 연구의 결과는 조종사의 교육 및 훈련프로그램을 개선하고 IIMC 상황에서 항공기 사고예방에 중요한 기여를 할 것으로 기대된다.

• 한국지리정보학회지
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• 제3권2호
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• pp.87-97
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• 2000

최근 마이크로파 원격탐사 기술이 지구 환경 분야에 활발하게 사용되고 있는데 특히 SAR(Synthetic Aperture Radar)를 이용한 지형 탐사 기술은 여러 응용분야가 넓어지고 있다. 미국 NASA/JPL이 주관하는 환태평양 AIRSAR 관측(PACRIM2)은 인공위성이나 우주 왕복선에 탑재할 관측기기 개발을 목적으로 하는 비행기 관측 프로그램이다. 본고는 PACRIM2의 개요와 관측 센서를 기술하고 각 센서를 통한 관측 예를 소개함으로 SAR 자료의 다양한 응용 가능성을 보였다.

• 대기
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• 제21권4호
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• pp.455-469
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• 2011

The Chugudae is a pedestal for the Chugugi. While many Chugudae were made during the Joseon Dynasty period, seven remained in existence until the early 20th century. Only five of them remain to this day-Gwansanggam (Royal Office of Astronomy and Meteorology), the Seonhwadang in Daegu, the Changdeok Palace, Tongyeong, and Yeongyeongdang. The Changdeok Palace Chugudae is the only existing model made not only as a meteorological instrument but also as a memorial statue. It has been a challenge to decipher 41 of the 368 characters in 'Chugugi-myeong (The title of the inscriptions on the Changdeok Palace Chugudae)' as these had been eroded. However, the interpretation of the full text of 'Chugugi-myeong' became possible thanks to the "Cheoljae Jinjeok (澈齋眞蹟)" which was discovered through this study. The key sentences of the 'Chugugi-myeong' include the reason for creation, the size and functions of the Chugugi and a eulogy to the reigns of King Sejong, Youngjo and Jeongjo. Moreover, its splendid design is worthy of further study. To conclude its true meaning and value, the Changdeok Palace Chugudae requires a more extensive investigation from the viewpoint of an art history.

• 자원환경지질
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• 제34권6호
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• pp.573-581
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• 2001

110 earthquake parameters (origin time, epicentral location and magnitude) were determined from 533 event records between 1905 and 1942 using data mainly from the "Annual Report of the Meteorological Observatory of the Government General of Tyosen" We adopted epicentral coordinates from the original reports for 34 events and from the Japanese Central Meteorological Observatory far another .34 events. We determined epicenters for 37 events using arrival time information from the reports. We adopted 4 epicenters from the International Seismological Summary and I from the Chinese bulletin. To determine the magnitude, we applied Tsuboi (1954) formula which is currently employed by Korea Meteorological Administration (KMA) for 94 events. For 16 events, we determined magnitude from the reef)reed felt epicentral areal using the correlation equation between known magnitude and felt area.

• 대기
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• 제19권1호
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• pp.1-8
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• 2009

We need water equivalent unit data of snowfall for the purpose of forecast and hydrology related research area. This study developed new method of automatic recording snowfall as weight unit with circle type plate using stain-gauge loadcell. Field test of instrument carried out at Daegwallyeong Obs. Station from 20 to 23 Jan. 2008 during heavy snowfall. There is 74.2cm snow depth and 54.6mm precipitation by Daegwallyeong Obs. Station. But the instrument of this study recorded 71.0mm of precipitation amount. Because of different observation method can cause more 15.4mm than Daegwallyeong Obs. Station. But this study gives the possibility of observation of new snow fall measurement under freezing conditions of snow. From the observation data the density of snowfall calculated from 0.09 to $1015g/cm_3$ from the observation period. And have a good relations between manual observation and automatic observation data from this study instrument with slope of 1.35 to 1.39.

• 대기
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• 제32권4호
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• pp.307-322
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• 2022

A drone has recently got attention as an instrument for weather observation in lower atmosphere because it can produce the high spatiotemporal resolution weather data even though the weather phenomenon is inaccessible. Sea fog is a weather phenomenon occurred in lower atmosphere, and has observational limitations because it occurs on the sea. Therefore, goal of this study is to analyze the vertical structures about inflow, development and dispersion of sea fog using the high-resolution weather data with the meteorological sensor-equipped drone. This study observed sea fogs in the west coast of the Korean peninsula from March to October 2021 and investigated one sea fog inflowed into the coast on June 8th 2021. θ_e - q_v diagrams (θ_e: equivalent potential temperature, q_v: water vapor ratio) and vertical wind structures were analyzed. At inflow of sea fog, moist adiabatically stable layer was formed in 0-300 m and prevailing wind was switched from south-southwesterly to west-southwesterly under 120 m. Both changes are favorable for sea fog on the location. θ_e and q_v plummeted in a layer 0-183 m. The inflowed sea fog developed from 183 m to 327 m by mixing with ambient atmosphere on top of sea fog. Also, strong mechanical turbulence near ground drove a vertical mixing under stable layer. At dispersion of sea fog, as θ_e on ground gradually increased, air condition was changed to neutral. Evaporation occurred on both bottom and top in sea fog. These results induced dissipation of sea fog.

• 대기
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• 제29권4호
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• pp.439-450
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• 2019

Present weather plays an important role not only for atmospheric sciences but also for public welfare and road safety. While the widely used state-of-the-art visibility and present weather sensor yields present weather, a single type of measurement is far from perfect to replace long history of human-eye based observation. Truly automatic present weather observation enables us to increase spatial resolution by an order of magnitude with existing facilities in Korea. 8 years of human-eyed present weather records in 19 sites over Korea are compared with visibility sensors and auxiliary measurements, such as humidity of AWS. As clear condition agrees with high probability, next best categories follow fog, rain, snow, mist, haze and drizzle in comparison with human-eyed observation. Fog, mist and haze are often confused due to nature of machine sensing visibility. Such ambiguous weather conditions are improved with empirically induced criteria in combination with visibility and humidity. Differences between instrument manufacturers are also found indicating nonstandard present weather decision. Analysis shows manufacturer dependent present weather differences are induced by manufacturer's own algorithms, not by visibility measurement. Accuracies of present weather for haze, mist, and fog are all improved by 61.5%, 44.9%, and 26.9% respectively. The result shows that automatic present weather sensing is feasible for operational purpose with minimal human interactions if appropriate algorithm is applied. Further study is ongoing for impact of different sensing types between manufacturers for both visibility and present weather data.