• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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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.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.151-156
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• 2021

The speed and direction of the earth's fluid motion is measured by a remote sensing method using electromagnetic waves. Using UHF radar and GPS Sonde, the vertical profile of fluid velocity was calculated by the Euler measurement method and the Lagrange measurement method, respectively. Since the wind direction, which is the direction of motion of the atmosphere, is indicated in the direction of the wind blowing, and a circular value of 0° - 360° is used, it is necessary to pay attention to statistical analysis. Errors caused by calculation conditions are provided, and the corrected accuracy of comparison results is improved by 400%.

• Wind and Structures
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• v.15 no.1
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• pp.65-86
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• 2012

Over the last decade substantial improvements have been made in our ability to observe the tropical cyclone boundary layer. Low-level wind speed maxima have been frequently observed in Global Positioning System dropwindsonde (GPS sonde) profiles. Data from GPS sondes and coastal Doppler radars were employed to evaluate the characteristics of tropical cyclone vertical wind profiles in open ocean conditions and at landfall. Changes to the mean vertical wind profile were observed azimuthally and with decreasing radial distance toward the cyclone center. Wind profiles within the hurricane boundary layer exhibited a logarithmic increase with height up to the depth of the wind maximum.

• Atmosphere
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• v.24 no.3
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• pp.391-402
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• 2014

This study investigated the performances of precipitable water vapor (PWV) retrieval from the sets of ground global positioning system (GPS) signals, each of which had different length of observing-session duration, for the purpose of obtaining as short session duration as possible that is required at the least for appropriate retrieval of the PWV for meteorological usage. The shorter duration is highly desirable to make the most use of the GPS instrument on board the mobile observation vehicle making measurements place by place. First, using Bernese 5.0 software the PWV retrieval was conducted with the data sets of GPS signals archived continuously in 30 seconds interval during 2-month period of January and February, 2012 at Bukgangneung site. Each of the PWVs produced independently using different session durations was compared to that of radio-sonde launched at the same GPS location, a Bukgangneung site. Second, the same procedure was done using the data sets obtained from the mobile observation vehicle that was operating at Boseong area in Jeonnam province during Changma observation campaign in 2013, and the results were compared to that at Bukgangneung site. The results showed that as the observing-session duration increased the retrieval errors decreased with the dramatic change happening between 3 and 4 hours of the duration. On average, the root mean square error (RMSE) of the retrieved PWV was around 1 mm for the durations of greater than 4 hours. The results at both the Bukgangneung (fixed site) and Boseong (mobile vehicle) seemed to be fairly comparable with each other. From this study it is believed that at least 4 hours of observing-session duration is needed for the retrieval of PWV from the ground GPS for meteorological usage using Bernese 5.0 software.