• 한국측량학회지
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• 제22권4호
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• pp.323-329
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• 2004

수증기는 지구 기후 변화를 관측하는데 있어서 가장 중요한 요소이며, 기상 예보 능력 향상을 위해 이용되고 있다. 그러나, 수증기 관측시 고가의 비용문제와 구조적인 이유로 정확하게 관측이 이루어지지 않고 있는 실정이다. PWV측정을 위한 GPS 기상학 기술은 현재 선진국을 중심으로 활발히 연구되고 있다. GPS 기상학의 주요 핵심은 가중 평균 온도식과 기상 데이터와 연관된 PWV 정확도에 있다. 본 연구에서는 2003년 1년 동안 국내에서 운용중인 라디오존데 관측소 6개소의 기상관측 데이터를 이용하여 선형 회귀 방법에 의한 우리나라에 적합한 가중 평균 온도식을 결정하였다. 새로운 한국형 가중 평균 온도식과 기존의 연구에 의한 가중 평균 온도식에 의하여 GPS 관측치와 라디오존데 관측치에 의한 PWV 정확도를 실험하였다.

• Journal of Positioning, Navigation, and Timing
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• 제3권4호
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• pp.143-147
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• 2014

The mean temperature is one of the key parameters in computing Precipitable Water Vapor (PWV) from Global Positioning System (GPS) measurements and is usually derived as a function of surface temperature through the use of a mean temperature equation (MTE). In this study, two new types of MTEs were developed as functions solely of the observation time so that the mean temperature can be obtained without surface temperature measurements. To validate the new models, we created one-year time series of GPS-derived PWV using the new MTEs and compared them with the radiosonde-observed PWV. The bias and root-mean-square error were on the other of ~1 mm and ~2 mm, respectively.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.47-51
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• 2006

Among Solar activities' events, the geomagnetic storms are believed to cause the largest atmospheric effects. The geomagnetic storm is a complex process of solar wind/magnetospheric origin. It is well known to affect severely on the ionosphere. However, this effect of this complex process will maybe act at various altitudes in the atmosphere, even including the lower layer and the neutral middle atmosphere, particularly the stratosphere. Nowadays, the GPS-derived ZTD (zenith tropospheric delay) can be transformed into the precipitable water vapor (PWV) through a function relation, and further has been widely used in meteorology, especially in improving the precision of Numerical Weather Prediction (NWP) models. However, such geomagnetic effects on the atmosphere are ignored in GPS meteorology applications. In this paper, we will investigate the geomagnetic storms' effects on the middle atmosphere and troposphere (0-100km) by GPS observations and other data. It has found that geomagnetic storms' effect on the atmosphere also appears in the troposphere, but the mechanism to interpret correlations in the troposphere need be further studied.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.47-53
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• 2004

Water vapor is an important parameter in monitoring changes in the Earth's climate and it can be used to improve weather forecasting However, it haven't observed accurately by reasons of structural and economic problem of observation. GPS meteorology technique for precipitable water vapor measurement is currently actively being researched an advanced nation. Main issue of GPS meteorology is an accuracy of PWV measurement related weighted mean temperature and meteorological data. In this study, the korean weighted mean temperature had been recalculated by a linear regression method based on meteorological observations from 6 radiosonde stations for 2003 year. We examined the accuracy of PWV estimates from GPS observations and Radiosonde observations by new korean weighted mean temperature and others.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2019년도 하계 학술발표초록집
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• pp.161-162
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• 2019

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.131-137
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• 2004

GPS/Meteorology technique for PWV monitoring is currently actively being researched an advanced nation. We deal with the monitoring of GPS derived PWV during the passage of Typhoon MAEMI. Typhoon MAEMI which caused a series damage was passed over in Korea peninsula from September 12 to September 13, 2003. We obtained GPS-PWV at 17th GPS permanent stations. We retrieve GPS data hourly and use Gipsy-Oasis II software. The GPS-PWV time series results demonstrate that PWV is, in general, high before and during the occurrence of the typhoon, and low after the typhoon.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 춘계학술발표회 논문집
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• pp.69-74
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• 2003

GPS/Meteorology technique for PWV monitoring is currently actively being researched an advanced nation. But, there is no detailed research on an evaluation of precision of GPS derived PWV measurements during the period of foul weather condition. Here, we deal with the precision of GPS derived PWV during the passage of Typhoon RUSA. Typhoon RUSA which caused a series damage was passed over in Korea from August 30 to September 1, 2002. We compared th tropospheric wet delay estimated from GPS observation and radio-sonde data at four sites(Suwon, Kwangju, Taegu, Cheju). The mean standard deviation of PWV differences at each site is ${\pm}$0.005mm. We also obtained GPS PWV at 13 GPS permanent stations(Seoul, Wonju, Seosan, Sangju, Junju, Cheongju, Taegu, Wuljin, Jinju, Daejeon, Mokpo, Sokcho, Jeju). GPS PWV time series shows, in general, peak value before and during th passage of RUSA, and low after the RUSA. GPS PWV peak time at each station is related to the progress of a typhoon RUSA. We obtained very similar result as we compare GMS satellite image with tomograph using GPS PWV and we could present th possibility of practical use by numerical model for weather forecast.

• 대한토목학회논문집
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• 제26권6D호
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• pp.1033-1041
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• 2006

본 연구에서는 2006년 7월 10일경 한반도에 영향을 미친 태풍 에위니아가 진행하는 동안 GPS/MET 기술을 이용하여 한반도의 GPS 가강수량의 시공간적 변화량을 계산하였다. 22개소의 GPS 상시관측소를 이용하여 1시간 간격의 대류권의 건조지연량과 습윤 지연량을 산출하고 지상기상관측 정보를 이용하여 가강수량으로 환산하였다. 가강수량으로 환산하기 위하여 가중 평균 기온식은 기존의 한국형 가중 평균 기온식 결정 연구에서 제시된 식을 적용하였다. 보다 정확한 GPS 가강수량의 결정을 위하여 기압 정보를 역해면 경정하여 관측소 해발고도상의 기압으로 환산하여 적용하였다. 최종적으로 GPS 가강수량도를 작성하여 태풍 에위니아 진행 동안 MTSAT 수증기 영상 및 레이더 영상과 함께 시공간적 변화를 비교하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.267-270
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• 2006

The International GNSS Service (IGS) has managed the global GNSS network and provided the highest quality GNSS data and products, which are GPS ephemerides, clock information and Earth orientation parameter, as the standard for GNSS. An important part of its works is to provide the precise orbits of GPS satellites. GPS satellites send their orbit information (broadcast ephemerides) to users and their accuracies are approximately 1.6 meters level, but those accuracies are not sufficient for the high precise applications which require millimeters precision. The current accuracies of the IGS final orbits are within 5 centimeters level and they are used for Earth science, meteorology, space science, and they are made by the IGS analysis centers and combined by the IGS analysis center coordinator. The techniques making the products are very difficult and require the high technology. The Korea Astronomy and Space Science Institute (KASI) studies to make the IGS products. In this study, we developed our own processing strategy and made GPS ephemerides using Bernese GPS software Ver. 5.0. We used the broadcast ephemerides as the initial orbits and processed the globally distributed 150 IGS stations. The result shows about 6 to 8 centimeters in root-mean-squares related to IGS final orbits in each day during a week. We expect that this study can contribute to secure our own high technology.

• Journal of Astronomy and Space Sciences
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• 제23권4호
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• pp.373-384
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• 2006

현재 GPS 가강수량 관련 연구에는 대부분 Bevis 평균온도식을 사용하고 있다. 그러나 Bevis 평균온도식은 북미대륙의 기상관측 자료를 이용하여 개발된 것이므로 기후조건이 다른 우리나라에 적용할 경우 가강수량 산출이 부정확할 수 있다. 이 연구에서는 우리나라 기상관측 자료를 이용하여 한반도 기상조건에 적합한 평균온도식을 개발하고, 이 개발된 평균온도식을 적용하여 가강수량을 산출한 후 Bevis 평균온도식과 기존 국내 연구에서 개발된 평균온도식을 이용한 가강수량과 비교하였다. 그 결과 각 평균온도식에 따른 가강수량은 이 연구에서 개발한 평균온도식을 기준으로 했을 때 지상기온이 높을 경우에 차이가 증가하며, 최대 $1{\sim}3mm$의 RMS 차이가 발생함을 알 수 있었다.