Rain Observation by an X- and Ka-band Dual-Wavelength Radar

[摘要] A rain observation by an X- and Ka-band dual-wavelength radar has been performed. The objective of this experiment is to explore the possibility of multi-wavelength radar for measuring rainfall rate. Simultaneous rain observations by C- and Ku-band radars were also performed. Correlations among measured Z- factors show that rain attenuation is significant only in the Ka-band for a short range when the observing range is a few km. After a method of obtaining an optimum averaging hit number is proposed, a dual-wavelength analysis using rain attenuation is applied to Ka- and X-band radar data and the result confirms the capability of providing an estimation of rainfall rate other than that by the conventional method. The dual-wavelength analysis is compared with a single wavelength analysis using rain attenuation and an advantage of dual-wavelength analysis is verified. The capability of the dual-wavelength analysis for retrieving a vertical structure of rain is demonstrated. A radar calibration using the dual-wavelength analysis is tested and a more accurate calibration than that comparing the rain gauge data is obtained.

[学科分类] 大气科学