• Journal of the Korean Society for Aviation and Aeronautics
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• v.3 no.1
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• pp.145-159
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• 1995

정확한 고도, 속도의 측정은 항공기의 효율적인 운영과 안전에 필수적이다. 정확한 고도의 측정은 지형 장애물의 회피와 항로상에서 최저 수직 고도 분리를 유지하기 위해 절대적으로 필요하다. 또한 정확한 속도의 측정은 저속(실속상태)에서 조종상실을 피하고 고속에서 항공기의 구조적 한계와 공기 역학적 한계의 초과를 방지한다. 따라서 비행시험을 통하여 고도와 속도를 정확히 보정해줌으로써 비행안전과 재산상의 손실을 막을 수 있다.

• Journal of the Korean association of regional geographers
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• v.6 no.2
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• pp.57-69
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• 2000

The purpose of this study is to identify distributional characteristics of autumn droughts in occurrence frequency and to analyze synoptic characteristics on the surface pressure fields and 500hPa levels for autumn droughts in Korea. The regional distributions of autumn droughts in occurrence frequency vary according to the monthly regional distributions of the precipitation variabilities in Korea. In september, the southwestern and the mid western parts of Korean Peninsula have high rate of drought frequency, while the eastern coast regions have low rate of it. It means that the regional distribution of the drought frequency in september indicates west-high and east-low pattern. In October, the regional distribution of the drought frequency shows low variations on regions, but in November the inland areas have low rate of drought frequency, whereas the coastal areas have high rate of it. Negative anomalies appear on the surface and 500hPa level, around Korean Peninsula during the drought period of early autumn. Positive height anomalies areas are extended from the Sea of Okhotsk to the central part of the North Pacific Ocean. It indicates that the occurrence frequencies of blocking high and ridge are high around the Sea of Okhotsk. When the pressure system, such as migratory anticyclone, stays around the Korean Peninsula, a drought occurs. In late autumn drought, the positive anomalies appear in the west and the negative anomalies in the east are generated, respectively and therefore, zonal wind is strong around Korean Peninsula. In consequence, occurrences of droughts in early autumn have a different mechanism from those of late autumn.

• Journal of the Korean earth science society
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• v.28 no.7
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• pp.947-956
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• 2007

In this article, the extratropical transition (ET) of tropical cyclone (TC) was investigated based on the case study covering the latest three TCs (Shanshaa Yaki, and Soulik) associated with ET evolution (onset and completion) using the objective 37 diagnostics of Evans and Hart (2003) and Hart (2003). At 500-hPa level, on an onset of ET, all three TCs entered the baroclinic zone. In a vertical cross-section analysis, three TCs before and at an onset of ET kept warm and humid throughout all levels around the TC center. However, these TCs after ET onset became relatively cold and dry over the western part of TC as the typical characteristics of ET concept model. Although our case study was not sufficient, it is concluded that the diagnostics of the ET onset and atmospheric structure change associated with Evans and Hart (2003) and Hart (2003) will be useful in ET operational forecast.

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.119-138
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• 1998

Recently measurements of atmospheric trace gases from satellite are vigorous. So the development of its data processing algorithm is important. In this study, retrievalof vertical ozone profile from the atmospheric transmittance measured by satellite solar occultation method and its sensitivity to temperature and pressure are investigated. The measured transmittance from satellite is assumed to be given by the limb path transmittance simulated using annual averaged Umkehr data for Seoul. The limb path transmittance between wavelengths $9.89{\mu}m$ and $10.2{\mu}m$ is simulated with respect to tangent heights using the ozone data of HALOE SIDS(Hallogen Occultation Experiment Simulated Instrument Data Set) as an initial profile. Other input data such as pressure and temperature are also from HALOE SIDS. Vertical ozone profile is correctly retrieved from the measured transmittance by onion-peeling method from 50km to 11km tangent heights with the vertical resolution of 3km. The bias error of $\pm0.001$ in measured transmittance, the forced error of $\pm3K$ in each layer temperature, and the forced $\pm3%$ error in each layer pressure are assumed for sensitivity tests. These errors are based on the ADEOS/ILAS error limitation. The error in ozone amount ranges from -6.5% to +6.9% due to transmittance error, from -9.5% to +10.5% due to temperature error, and from -5.1% to +5.4% due to pressure error, respectively. The present study suggests that accurate vertical ozone profile can be retrieved from satellite solar occultation method. Accuracy of vertical temperature profile is especially important in the retrieval of vertical ozone profile.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.165-170
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• 2015

The topic of this paper is the advanced absolute altitude determination for 3-D positioning using barometric altimeter and the reference station. Barometric altimeter does not provide absolute altitude because atmosphere pressure always varies over the time and geographical location. Also, since Global Navigation Satellites system such as GPS, GLONASS has geometric error, the altitude information is not available. It is the reason why we suggested the new method to improve the altitude accuracy. This paper shows 3-D positioning algorithm using absolute altitude determination method and evaluates the algorithm by real field tests. We used an accurate altitude from RTK system in Seoul as a reference data and acquired the differential value of pressure data between a reference station and a mobile station equipped in low cost barometric altimeter. In addition, the performance and advantage of the proposed method was evaluated by 3-D experiment analysis of PNS and CNS. We expect that the proposed method can expand 2-D positioning system 3-D position determination system simply and this 3-D position determination technique can be very useful for the workers in the field of fire-fighting and construction.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.121.1-121.1
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• 2013

인공위성 및 우주발사체가 해당 궤도 및 고도에서 정상적으로 기능을 수행할 수 있는지 확인하기 위해 진공챔버 내부에 시험 대상을 설치하고 내부 압력을 낮추어 해당 궤도와 고도를 모사하게 된다. 반복적인 진공 시험을 수행하다 보면, 진공 챔버 내에 인지하지 못한 수분이 잔류하는 경우가 발생하는데, 이 때의 챔버 내부 압력 변화는 수분이 존재하지 않는 경우와는 매우 다른 양상을 보인다. 본 연구에서는 진공챔버 내부에 수분이 존재하는 경우를 모사하여, 포화증기압에서 액체의 잠열 이상으로 외부로부터 열을 받는 구간과 그렇지 못한 경우에 대한 현상을 살펴보고 이에 따른 챔버 내부 압력 변화에 대해 고찰하였다.

• Korean Journal of Remote Sensing
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• v.12 no.2
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• pp.126-138
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• 1996

The characteristics of rapid development of the low pressure system over the East Sea from 06 to 08 Nov., 1995 has been analyzed in detail by the synoptic numerical products and satellite observations. The Low system was initially triggered the development of the baroclinic leaf cloud over the border of the northern part of Korea and China and moved eastward and then developed explosively com-ma or lambda type cloud system over the East Sea. To forecast well the general development and movement of the coastal winter cyclone over the East Sea popularly in a numerical simulation by several scientists, the large baroclinicity, continuous support of water vapor, and sequential cold outbreak over the warm sea surface have been more commonly concerned about. The cyclone which the central surface pressure was dropped 40hPa within 24 hours has often accompanied strong wind and heavy snow- or rain-fall in the winter season. In all successive observations with 12-hourly satellite imagery and analyzed meteorological variables in this period, the centers of the sea-level pressure and 500hPa geopotential height associated with this cyclone were typically illustrated by moving farther eastward using GMS combined enhanced IR images. The maxi-mum wind sustained by this system with the intensity and central pressure of tropical storm was about 60 knots with the center pressure drop of 44hPa/day similar to the North American cyclonic bomb and Atlantic storm.

• ICROS
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• v.14 no.3
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• pp.64-69
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• 2008

• The Korean Journal of Quaternary Research
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• v.13 no.1
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• pp.45-52
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• 1999

This study examined the spatial distribution of precipitation in Donghae-Shi. The daily, monthly precipitaion on the 2 stations, 3 AWS(Automatic Weather Station) were analyzed by altitudinal distribution, the air pressure type and days of daily precipitation. The results of the study are as follows. 1 Hour greatest precipitation is 62.4mm(1994. 10. 12), Daily greatest precipitation, 200mm(1994. 10. 12), Monthly greatest precipitation, 355.5mm(1994. 10), Maximum depth of snow fall, 35.5cm(1994. 1. 29) in Donghae-Shi, 1993∼1997. Altitudinal distribution of precipitation in Summer tends to have more precipitation at higher altitude, in Winter, high mountains and coast have more precipitation than other sites do. The heavy rainfall in Donghae-Shi is mainly formed by a Typhoon, next is Jangma front. The number of consecutive days of daily precipitation $\geq$20mm is 81days, 44days of those appeared in Summer season. The synoptic environment causes the difference in observed the heavy snowfall amount between high mountains and coast.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.95-97
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• 2010

최근 겨울철 온난화 경향이 뚜렷해지면서 강수형태가 비로 내리는 경우가 잦아지고 있다. 또한 대륙고기압이 확장할 때는 기압골의 영향으로 강우에서 강설로 변하는 예가 종종 나타나고 있다. 강수유형의 판단은 겨울철 중요한 예보요소 중 하나로 본 연구는 중서부지방의 2010년 2월 4일부터 12일까지의 사례기간동안 일기도, AWS관측자료, 위성, KLAPS(층후, 빙결고도, 상당온위) 자료를 바탕으로 하여 강우에서 강설로 변하는 강수형태를 분석한 것이다.