• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.819-826
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• 2020

The UHF band wind profiler radars of the Korea Meteorological Administration (KMA), which produces the vertical profile of the wind, need to be calibrated for better performance. The capabilities of the radar in detecting even light precipitation were used for the calibration of which reference takes the hourly series of ground rainfall rate measured by a rain gauge at the radar site. This calibration must be renewed regularly according to the methodology implemented in this work since errors occur on the wind vectors in the clear sky without reflectivity calibration. Comparing the wind by wind profiler with that by radiosonde, the optimal radar constant contributed to the improvement of wind accuracy.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.305-312
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• 2018

The quality of the radar and profiler network was estimated to forecast difficult meteorological situations. A network of UHF Doppler wind profilers and Doppler weather radars have been deployed all over the Korean Peninsular, with dense spatial resolution between instruments. The radar network allows to retrieve the three dimensional dynamics and to analyze the numerical model outputs at small and meso scales. This work has seldom been performed in any other place of the world, with such a high resolution. The wind field from radar network is a good agreement with the background wind fields based on the numerical modeling. This study will be helpful to forecast severe weathers as well as local meteorological phenomena.

• Journal of Environmental Science International
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• v.25 no.2
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• pp.267-280
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• 2016

Ground echo is radar return from stationary targets such as buildings and trees. Wind vectors from the wind profile radar in Gangneung are affected by ground echoes due to the complex mountainous terrain located to the west and the south. These ground echoes make a spurious peak close to the direct current (DC) line signal in Doppler spectra. Wind vectors polluted by ground clutters were determined from spectra of oblique beams. After eliminated the terrain echoes, the accuracy of wind vector compared with radiosonde was improved about 68.4% and its relative coefficient was increased from 0.58 to 0.97.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.61-68
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• 2019

In addition to non-meteorological echoes, meteorological echoes with large scattering effects, such as precipitation, cause errors in wind data measured by wind profiler. In the rainfall situation, the Doppler spectrum of wind profiler shows both the rainfall signal and the atmospheric signal as two peaks. The vertical radial velocity is very large due to the falling rain drop. The radial velocity contaminated by rainfall decreases the accuracy of the horizontal wind vector and leads to inaccurate weather analysis. In this study, we developed an algorithm to process raw data of wind profiler and distinguished rainfall signal and wind signal by partitioning bimodal peak for Doppler spectrum in rainfall environment.

• Journal of Environmental Science International
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• v.25 no.9
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• pp.1241-1251
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• 2016

A minimum threshold for the signal to noise ratio ($SNR_{min}$) has to be set in the data processing system of wind profiler radar (WPR). The data collection rate and the accuracy of the WPR wind vector depend on the $SNR_{min}$. The WPR at Uljin is operated with an $SNR_{min}$ of 1 dB which is a relatively large threshold. We found that the accuracy and the continuity of the WPR wind vector with height were directly related to the variability of the SNR and vertical gradient of the squared refractive index. We investigated a quantitative method for determining a new $SNR_{min}$ for the WPR at Uljin and it was evaluated with radiosonde data. The accuracy and continuity of the wind vector from an SNR of less than 1 dB, began to decrease at an altitude of 3.5 km. Most of the SNR values were less than -3.5 dB in altitudes higher than 3.5 km. We retrieved high-accuracy wind vectors at altitudes over 3 km where measurements were deficient with an $SNR_{min}$ of 1 dB.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.277-290
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• 2018

Wind data observed by wind profiler provide wind vectors with the altitudes using PCL1300, wind computation program. As a result of application with parameters set in program currently, it is difficult to compute wind vectors in the upper air over 3 km. This id because a very strict criterion for parameters removes large amounts of data. In this study, therefore, we improve the methods of application by resetting parameters to expand data collection area of wind vectors and reduce underestimation. Although the acquisition rate of the wind vector increased from 72.2% to 92.2%, the RMSE of the wind speed maintained 1.5 m/s - 3.1 m/s, which is less than 15% of the error rate at each altitude.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.429-436
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• 2021

The wind profilers operated by the Korea Meteorological Administration observe in a low mode for intensive observation of the low levels and a high mode for intensive observation of the high levels. The LAP-3000 wind profiler installed in Bukgangneung and Changwon is characterized by the same sampling frequency of the low mode and the high mode, allowing to compare winds observed in both modes at the same altitude. As a result of analyzing the wind speed of the two points for one year in 2020, the correlation between the two modes was up to 0.2 lower than the correlation with radiosonde. The T-test for the wind speed of the two modes showed a particularly significant difference in October, where the temperature and specific humidity fluctuate frequently. The difference in the development of the atmospheric boundary layer affects the accuracy of the wind speed depending on the observation mode.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.275-282
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• 2019

Clusters generated by features such as mountains or buildings are considered as the contaminated data that are independent of atmospheric phenomena. The basic way to reduce the clutter signal is to install a clutter fence around the wind profiler. In order to investigate the effect of clutter fence on the wind profiler data, the wind vector collection rate and wind vector accuracy of wind profiler was investigated before and after clutter fence installation. The clutter fence of wind profiler contributed to improve the data quality as well as the data collection rate.

• 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%.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1575-1577
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• 2002

In this research we propose a method far rain rate estimation by using Doppler spectrum's data of wind profiler. The Doppler spectrum is used to calculate the wind velocity and wind direction. But in this research uses the parameters from Doppler spectrum, it calculates the rain rate. The rain rate estimation in this method will be compared to the obtained rain rate from the surface rain gauge. Two equipments are installed in the same area. The correlation coefficient between rain rate measuring method is 0.65.