CAJ | 학술논문

文中分析了X波段双线偏振雷达衰减订正各种方法的特点,考虑到差传播相移率(KDP)作为衰减订正的一种有效途径,以及由于KDP值较小,数据质量不稳定,往往导致订正误差较大,因此提出了同时利用水平反射率因子ZH与KDP进行衰减订正的ZH-KDP综合法.基于同样的考虑,在随后利用ZH、KDP进行降水估测时,提出了ZH-KDP-R综合估测方法.利用中国科学院寒区旱区环境与工程研究所和成都锦江电子系统工程有限公司,在研制3.2 cm波长同时收发式多普勒偏振天气雷达过程中,2005年8月在平凉外场试验取得的一批观测资料,对提出的衰减订正综合法及降水估测综合法的效果进行了分析检验,结果表明,ZH-KDP综合法对ZH、ZDR有稳定的订正效果,并且订正速度快,能够达到实时运行的要求.2005年8月11日15:08:03-22:05:46,间隔5-12 min不等,雷达开机取得了连续的观测资料,通过对这次降水过程的对比分析表明,ZH-KDP-R综合估测法比单因子KDP-R法、Z-R关系法,适用估测的降水强度变化范围广,与自动雨量记的观测结果较为吻合.Z-R关系法中,利用订正后的ZH值,比利用订正前的ZH值,降水估测值与雨量记实测值的误差明显减小,说明衰减订正后的雷达数据质量有明显的改善.
문중분석료X파단쌍선편진뢰체쇠감정정각충방법적특점,고필도차전파상이솔(KDP)작위쇠감정정적일충유효도경,이급유우KDP치교소,수거질량불은정,왕왕도치정정오차교대,인차제출료동시이용수평반사솔인자ZH여KDP진행쇠감정정적ZH-KDP종합법.기우동양적고필,재수후이용ZH、KDP진행강수고측시,제출료ZH-KDP-R종합고측방법.이용중국과학원한구한구배경여공정연구소화성도금강전자계통공정유한공사,재연제3.2 cm파장동시수발식다보륵편진천기뢰체과정중,2005년8월재평량외장시험취득적일비관측자료,대제출적쇠감정정종합법급강수고측종합법적효과진행료분석검험,결과표명,ZH-KDP종합법대ZH、ZDR유은정적정정효과,병차정정속도쾌,능구체도실시운행적요구.2005년8월11일15:08:03-22:05:46,간격5-12 min불등,뢰체개궤취득료련속적관측자료,통과대저차강수과정적대비분석표명,ZH-KDP-R종합고측법비단인자KDP-R법、Z-R관계법,괄용고측적강수강도변화범위엄,여자동우량기적관측결과교위문합.Z-R관계법중,이용정정후적ZH치,비이용정정전적ZH치,강수고측치여우량기실측치적오차명현감소,설명쇠감정정후적뢰체수거질량유명현적개선.
Except its smaller antenna, mobile convenience and low cost, X-band radar has a higher resolution than the S-band's, and C-band's, and therefore can therefore detect more subtle microphysical processes information of clouds, raindrop, hail and hydrometeor etc. As an effective complementarity of new generation weather radar network, it can be widely applied to the monitoring and warning of disastrous weather such as heavy rain and hails, the operations guidance and effect evaluation of weather modification, and the managements of reservoir, urban area and aviation etc., therefore, it has a huge potential in the remote sensing of clouds and precipitation and in nowcasting. Compared to ordinary Doppler weather radars, dual polarimetric radar have a very distinct advantage in the quantitative estimation of precipitation, however, the radar signal attenuation is an important shortcoming which hampers the wide application of X-Band radar, especially in precipitation estimate. Various kinds of signal attenuation correction methods for X-band dual linear polarimetric radar are analyzed, the specific differential phase shift KDP is considered as an effective approach on attenuation correction. However, the values of KDP for light rain are too small, which results in instable quality and larger error, therefore, reflectivity and specific differential phase shift are combined together in the ZH-KDP method to correct the attenuation error. Based on the similar consideration, ZH-KDP-R combined technique is also suggested when ZH and KDP are used to estimate rainfall. During the development stage of the synchronous transmitting and receiving dual polarimetric Doppler weather radar with 3.2 cm wave length by the Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences and Jinjiang Electronic System Engineering Co., Ltd. Chendu, a set of observational data were obtained in the field experiment in Pingliang in August 2005. By means of the set of observational data, the effect of combined attenuation correction and rainfall estimation methods are examined, the results indicate that the ZH-KDP combined method is effective in correcting ZH and KDP, and furthermore, the correction speed is able to meet the requirement of real time operations. Some continuous detection records with the 5-12 minute intermission were gained in the time period of 15:08:03-22:05:46 BST August 11, 2005. The contrastive analysis of this precipitation process show that ZH-KDP-R combined estimation technique is better than single factor methods such as KDP-R or Z-R, more suitable when the precipitation intensity varies widely, and the estimated results is in good agreement with automatic rain-gauge records. As to the Z-R, relation, the deviations between precipitation estimations and available rain-gauge measurements decrease obviously when the corrected ZH is used, indicating that the radar data quality are obviously improved after the attenuation correction.