• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.5
• /
• pp.819-826
• /
• 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 Institute of Internet, Broadcasting and Communication
• /
• v.20 no.3
• /
• pp.43-51
• /
• 2020

In this paper, the design of 64 array antennas applied to RWP (Radar Wind Profiler) was described. The design point of the antenna is to ensure isolation between each element and to match the vertical / horizontal radiation pattern. To this end, a single element of the array antenna was proposed as a Bend dipole type, and through simulation, When sequentially sending 5 beams including vertical, the east/west/south/north direction was ±20°, and it was confirmed that no Grating Lobe occurred when steering the beam. The 64 array antenna proposed in this paper was designed with performance equal to or higher than that of overseas products, and was confirmed to be applicable to RWP.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.6
• /
• pp.1037-1044
• /
• 2020

Since radar wind profiler (RWP) provides wind field data with high time and space resolution in all weather conditions, their verification of the accuracy and quality is essential. The simultaneous wind measurement from rawinsonde is commonly used to evaluate wind vectors from RWP. In this study, the simulation algorithm which produces the spectrum and raw time series (I/Q) data from the average values of moments is presented as a step-by-step verification method for the signal processing algorithm. The possibility of the simulation algorithm was also confirmed through comparison with the raw data of LAP-3000. The Doppler power spectrum was generated by assuming the density function of the skew-normal distribution and by using the moment values as the parameter. The simulated spectrum was generated through random numbers. In addition, the coherent averaged I/Q data was generated by random phase and inverse discrete Fourier transform, and raw I/Q data was generated through the Dirichlet distribution.

• Journal of Korea Multimedia Society
• /
• v.22 no.12
• /
• pp.1396-1403
• /
• 2019

The radar wind profiler data contaminates with various non-atmospheric components that produce errors in moments and wind velocity estimations. This study implemented an adaptive Gaussian model to detect and remove the clutter from the radar return. This model includes DC filtering, ground clutter recognition, Gaussian fitting, and cost function to mitigate the clutter component. The adaptive model tested for the various types of clutter components and found that it is effective in clutter removal process. It is also applied for the both time series and spectrum datasets. The moments estimated using this method are compared with those derived using conventional DC-filtering clutter removal method. The comparisons show that the proposed method effectively removes the clutter and produce reliable moments.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.3
• /
• pp.393-398
• /
• 2022

During the test operation period of the wind profiler prototype, radio frequency interference (RFI) contamination occurred in the spectrum. The reference of the RFI that removed the algorithm appearing in the wind profiler spectrum were investigated, and a new algorithm was developed to remove the RFI. First, it was filtered with a threshold value of 0.1 m/s of the spectral width, and the range of the number of gates with the same radial velocity was determined according to whether the beam was a vertical beam or an oblique beam. RFI contamination was removed through filtering and scanning of non-weather signals, and the continuity of wind vectors calculated from the improved spectral radial velocity was verified.

• Journal of Environmental Science International
• /
• v.25 no.2
• /
• pp.267-280
• /
• 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
• /
• v.14 no.1
• /
• pp.61-68
• /
• 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.

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

• Journal of Environmental Science International
• /
• v.25 no.9
• /
• pp.1241-1251
• /
• 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
• /
• v.13 no.2
• /
• pp.305-312
• /
• 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.