设为首页
加入收藏
Quality Control and Evaluation on Non-cloud Echo of Ka-band Cloud Radar
-
摘要: 针对Ka波段毫米波云雷达观测中出现的非云回波，提出改进的质量控制方法，并利用2018年9月—2020年8月福建平和观测资料，定量评估质量控制效果及其对云-降水探测的影响。结果表明：提出的改进方法能较好改善雷达探测结果，可有效滤除非云回波。非云回波对3 km高度以下的弱云探测有重要影响，且非云回波的探测率与雷达灵敏度密切相关，整体随高度上升而下降；同时非云回波存在明显的日变化特征，午后—前半夜因湍流活动较强，非云回波的探测率也较高；后半夜—日出前因湍流活动减弱，非云回波的探测率逐渐下降。Abstract: Aiming at non-cloud echoes in Ka-band millimeter wave cloud radar observation, an improved data quality control method is proposed. Using the observation at Pinghe of Fujian from September 2018 to August 2020, the quality of the radar is quantitatively evaluated to study the actual impact of data quality control on cloud-precipitation detection. The non-cloud echoes show the characteristics of weak radar reflectivity factor (Z) and strong depolarization ratio (R) at Pinghe. But statistics show that there is difference from those of Qinghai-Tibet Plateau or Guangdong. Therefore, using the radar reflectivity factor (Z) less than -5 dBZ and linear depolarization ratio (R) greater than -22 dB as the judgment condition, and with the aid of filtering, non-cloud echoes can be effectively filtered. At the same time, a typical example is used to verify the effectiveness of the algorithm. Non-cloud echoes have a significant effect on the detection of cloud below 3 km, especially weak echoes. Non-cloud echoes account for 9.20% of all radar reflectivity factor samples, and 34.05% of all radar linear depolarization ratio samples. For the weak echo below -5 dBZ, the impact of non-cloud echoes is more significant, which accounts for 67.20% of all radar reflectivity factor sample. The detection rate of non-cloud echoes matter is closely related to the radar sensitivity, and the overall decrease with the height increaseing. The detection rate of non-cloud echoes decreases with the height increaseing. Meanwhile, non-cloud echoes have a certain relationship with the boundary layer, with an obvious diurnal change trend. From afternoon to midnight, due to strong turbulent activity, the detection rate of non-cloud echo matter is also higher, and the peak occurs at 1700 BT. From midnight to sunrise, due to the weakening of turbulent motion, the detection rate of non-cloud echo gradually decreases, and the lowest value occurs at 0400 BT. Non-cloud echoes have a significant effect on the vertical distribution of cloud precipitation. After quality control, the number of samples at the height of 0.12-2.5 km for radar reflectivity factor decrease by 17.68%, and the number of samples at the height of 0.12-4 km for radar linear depolarization ratio decrease by 14.29%.
-
图 1 2018年9月—2020年10月福建平和雷达观测的非云回波和云-降水回波Z与R概率分布
Fig. 1 Probability distribution of measured Z and R of non-cloud and cloud-precipitation echoes observed by Pinghe radar in Fujian from Sep 2018 to Oct 2020
图 2 2018年9月—2020年8月福建平和3 km高度以下质量控制前后的Z和R频次分布
Fig. 2 Frequency distributions of measured Z and R below 3 km altitude before and after quality control observed by Pinghe radar in Fujian from Sep 2018 to Aug 2020
图 3 2018年9月—2020年8月福建平和非云回波的时间-高度频次分布和整层高度总频次
Fig. 3 Time-height frequency distributions of non-cloud echoes and frequency distribution of the whole levels observed by Pinghe radar in Fujian from Sep 2018 to Aug 2020
图 4 2018年9月—2020年8月福建平和非云回波质量控制前后Z和R的频次-高度分布
Fig. 4 Frequency-height distributions of measured Z and R of non-cloud echoes before and after quality control observed by Pinghe radar in Fujian from Sep 2018 to Aug 2020
图 5 2019年4月18日12:00—20:00福建平和雷达上空观测的包含低空碎积云和深对流降水云的质量控制前后回波对比
Fig. 5 Comparison of low altitude cumulus cloud and deep convective precipitation cloud echoes before and after radar quality control observed by Pinghe radar in Fujian from 1200 BT to 2000 BT on 18 Apr 2019
图 6 2019年5月19日17:00—23:00福建平和雷达上空观测的包含低空层云、积云和高空卷积云的回波质量控制前后回波对比
Fig. 6 Comparison of low altitude stratus clouds, cumulus and high altitude cirrocumulus echoes before and after quality control of observed by Pinghe radar in Fujian from 1700 BT to 2300 BT on 19 May 2019
图 7 2018年9月2日15:00—23:00福建平和雷达上空观测的包含低空积云和弱对流性降水云的质量控制前后回波对比
Fig. 7 Comparison of low altitude cumulus cloud and weak convective precipitation cloud echoes before and after quality control observed by Pinghe radar in Fujian from 1500 BT to 2300 BT on 2 Sep 2018
表 1 Ka波段毫米波云雷达主要性能参数
Table 1 Major performance parameters for Ka-band millimeter wave cloud radar
参数 数值 工作频率 35 GHz±500 MHz 波束宽度 0.4° 脉冲重复频率 5988~16666 Hz 峰值功率 20 W 时间分辨率 1 min 空间分辨率 30 m 观测资料 Z/V/σV/R 信号处理方式 FFT 
下载: 导出CSV
表 2 4种探测模式主要参数
Table 2 Major parameters of 4 detection modes
参数 边界层模式 中云模式 高云模式 降水模式 脉冲宽度/μs 0.2 8 24 0.2 脉冲重复频率/Hz 16666 8333 5988 5988 驻波时间/s 0.98 1.97 1.37 1.37 相干积累数 4 2 1 1 非相干积累数 16 32 32 32 FFT点数 256 256 256 256 距离分辨率/m 30 30 30 30 有效探测高度/km 0.12~7.5 1.47~7.5 3.87~20 0.12~20 最大不模糊速度/(m·s-1) 8.93 8.93 12.83 12.83 速度分辨率/(cm·s-1) 6.98 6.98 10.02 10.02
下载: 导出CSV
-
[1] 郭学良,付丹红,胡朝霞.云降水物理与人工影响天气研究进展(2008-2012年).大气科学,2013,37(2):351-363. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXK201302013.htmGuo X L, Fu D H, Hu Z X. Progress in cloud physics precipitation and weather modification during 2008-2012. Chinese Journal of Atmospheric Sciences, 2013, 37(2): 351-363. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXK201302013.htm [2] 程周杰, 刘宪勋, 朱亚平. 双偏振雷达对一次水凝物相态演变过程分析. 应用气象学报, 2009, 20(5): 594-601. doi: 10.3969/j.issn.1001-7313.2009.05.011Cheng Z J, Liu X X, Zhu Y P. A process of hydrometeor phase change with dual-polarimetric radar. J Appl Meteor Sci, 2009, 20(5): 594-601. doi: 10.3969/j.issn.1001-7313.2009.05.011 [3] 郭学良, 方春刚, 卢广献, 等. 2008-2018年我国人工影响天气技术及应用进展. 应用气象学报, 2019, 30(6): 641-650. doi: 10.11898/1001-7313.20190601Guo X L, Fang C G, Lu G X, et al. Progress of weather modification technologies and applications in China from 2008 to 2018. J Appl Meteor Sci, 2019, 30(6): 641-650. doi: 10.11898/1001-7313.20190601 [4] 施丽娟, 徐小峰, 李柏, 等. 雷达资料在登陆台风"桑美"数值模式中的应用. 应用气象学报, 2009, 20(3): 257-266. doi: 10.3969/j.issn.1001-7313.2009.03.001Shi L J, Xu X F, Li B, et al. Application of Doppler radar data to the landfalling Typhoon Saomai simulation. J Appl Meteor Sci, 2009, 20(3): 257-266. doi: 10.3969/j.issn.1001-7313.2009.03.001 [5] 葛俊祥, 汪洁, 王金虎, 等. 毫米波气象雷达发展与应用. 南京航空航天大学学报, 2018, 50(5): 577-585. https://www.cnki.com.cn/Article/CJFDTOTAL-NJHK201805001.htmGe J X, Wang J, Wang J H, et al. Development and application of millimeter wave weather radar. Chinese Journal of Nanjing University of Aeronautics & Astronautics, 2018, 50(5): 577-585. https://www.cnki.com.cn/Article/CJFDTOTAL-NJHK201805001.htm [6] Kollias P, Miller M A, Luke E P, et al. The atmospheric radiation measurement program cloud profiling radars: Second-generation sampling strategies, processing, and cloud data products. J Atmos Oceanic Technol, 2007, 24: 1199-1214. doi: 10.1175/JTECH2033.1 [7] Görsdorf U, Lehmann V, Bauter-Pfundstein M, et al. A 35-GHz polarimetric Doppler radar for long-term observations of cloud parameters-description of system and data processing. J Atmos Oceanic Technol, 2015, 32: 675-690. doi: 10.1175/JTECH-D-14-00066.1 [8] Liu L P, Zheng J F, Ruan Z, et al. Comprehensive radar observation of clouds and precipitation over the Tibetan Plateau and preliminary analysis of cloud properties. J Meteor Res, 2015, 29(4): 547-561. http://www.cqvip.com/QK/88418X/201504/666234442.html [9] 唐英杰, 马舒庆, 杨玲, 等. 云底高度的地基毫米波云雷达观测及其对比. 应用气象学报, 2015, 26(6): 680-687. doi: 10.11898/1001-7313.20150604Tang Y J, Ma S Q, Yang L, et al. Observation and comparison of cloud-base heights by ground-based millimeter-wave cloud radar. J Appl Meteor Sci, 2015, 26(6): 680-687. doi: 10.11898/1001-7313.20150604 [10] 钟正宇, 马舒庆, 杨玲, 等. 结合风廓线雷达的毫米波衰减特性初步研究. 应用气象学报, 2018, 29(4): 496-504. doi: 10.11898/1001-7313.20180410Zhong Z Y, Ma S Q, Yang L, et al. Progress of weather modification technologies and applications in China from 2008 to 2018. J Appl Meteor Sci, 2018, 29(4): 496-504. doi: 10.11898/1001-7313.20180410 [11] 陶法, 官莉, 张雪芬, 等. Ka波段云雷达晴空回波垂直结构及变化特征. 应用气象学报, 2020, 31(6): 719-728. doi: 10.11898/1001-7313.20200607Tao F, Guan L, Zhang X F, et al. Veriation and vertical structure of clear-air echo by Ka-band cloud radar. J Appl Meteor Sci, 2020, 31(6): 719-728. doi: 10.11898/1001-7313.20200607 [12] 仲凌志, 刘黎平, 葛润生. 毫米波测云雷达的特点及其研究现状和展望. 地球科学进展, 2009, 24(4): 383-391. doi: 10.3321/j.issn:1001-8166.2009.04.004Zhong L Z, Liu L P, Ge R S. Characteristics about the millimeter-wavelength radar and its status and prospect in and abroad. Advances in Earth Science, 2009, 24(4): 383-391. doi: 10.3321/j.issn:1001-8166.2009.04.004 [13] Kropfli R A, Kelly R D. Meteorological research applications of mm-wave radar. Meteorol Atmos Phys, 1996, 59: 105-121. doi: 10.1007/BF01032003 [14] Lhermitte R M. 94 GHz Doppler radar for cloud observation. J Atmos Oceanic Technol, 1987, 4: 36-48. doi: 10.1175/1520-0426(1987)004<0036:AGDRFC>2.0.CO;2 [15] 孙豪, 刘黎平, 郑佳锋. 不同波段垂直指向雷达功率谱密度对比. 应用气象学报, 2017, 28(4): 447-457. doi: 10.11898/1001-7313.20170406Sun H, Liu L P, Zheng J F. Comparison of Doppler spectral density data by different bands pointing vertically radars. J Appl Meteor Sci, 2018, 28(4): 447-457. doi: 10.11898/1001-7313.20170406 [16] 商建, 郭杨, 吴琼, 等. 我国Ka频段降水测量雷达机载校飞试验结果. 应用气象学报, 2011, 22(5): 590-596. doi: 10.3969/j.issn.1001-7313.2011.05.009Shang J, Guo Y, Wu Q, et al. Airborne field campaign results of Ka-band precipitation measuring radar in China. J Appl Meteor Sci, 2011, 22(5): 590-596. doi: 10.3969/j.issn.1001-7313.2011.05.009 [17] Babb D M, Verlinde J, Albrecht B A. Retrieval of cloud microphysical parameters from 94-GHz radar Dopple power spectra. J Atmos Oceanic Techol, 1999, 16: 489-503. doi: 10.1175/1520-0426(1999)016<0489:ROCMPF>2.0.CO;2 [18] Pasqualucci F, Bartram B W, Kropfli R A, et al. A millimeter-wavelength dule-polarization Doppler radar for cloud and precipitation studies. J Appl Meteor Climatol, 1983, 22(5): 758-765. doi: 10.1175/1520-0450(1983)022<0758:AMWDPD>2.0.CO;2 [19] 仲凌志. 毫米波测云雷达系统的定标和探测能力分析及其在反演云微物理参数中的初步研究. 南京: 南京信息工程大学, 2009.Zhong L Z. Calibration and Capability Analysis of China New Generation of Cloud Radar-HMBQ and Its Preliminary Application in Retrieving Cloud Microphysics Parameter. Nanjing: Nanjing University of Information Science & Technology, 2009. [20] 宗蓉. 毫米波雷达对云宏观微观特性的探测和研究. 南京: 南京信息工程大学, 2013.Zong R. Studies of Cloud Macro-and Microphysical Properties using China New Generation Millimeter-wavelength Radar. Nanjing: Nanjing University of Information Science & Technology, 2013. [21] 郑佳锋. Ka波段-多模式毫米波雷达功率谱数据处理方法及云内大气垂直速度反演研究. 南京: 南京信息工程大学, 2016.Zheng J F. Doppler Spectral Data Processing Methods of Ka-band Multi-mode mm-wave Radar and Air Vertical Speed Retrieval in Clouds. Nanjing: Nanjing University of Information Science & Technology, 2016. [22] Liu L P, Ding H, Dong X B, et al. Applications of QC and merged Doppler spectral density data from Ka-band cloud radar to microphysics retrieval and comparison with airplane in situ observation. Remote Sensing, 2019, 11: 1595-1613. doi: 10.3390/rs11131595 [23] Moran K P, Martner B E, Post M J, et al. An unattended cloud-profiling radar for use in climate research. Bull Amer Meteor Soc, 1998, 79: 443-455. doi: 10.1175/1520-0477(1998)079<0443:AUCPRF>2.0.CO;2 [24] 马书笛. 雷达回波信号MTI与脉冲压缩研究. 哈尔滨: 哈尔滨工程大学, 2019.Ma S D. Research on Radar Return Signal MTI and Pulse Compression. Harbin: Harbin Engineering University, 2019. [25] Luke E P, Pavlos K, Johnson K L, et al. A technique for the automatic detection of insect clutter in cloud radar returns. J Atmos Oceanic Technol, 2008, 25(9): 1498-1513. doi: 10.1175/2007JTECHA953.1 [26] Clothiaux E E, Ackerman T P, Mace G G, et al. Objective determination of cloud heights and radar refectivities using a combination of active remote sensors at the ARM CART sites. J Appl Meteor, 2000, 39: 645-665. doi: 10.1175/1520-0450(2000)039<0645:ODOCHA>2.0.CO;2 [27] Geerts B, Miao Q. The use of millimeter Doppler radar echoes to estimate vertical air velocities in the fair-weather convective boundary layer. J Atmos Oceanic Technol, 2005, 22: 225-246. doi: 10.1175/JTECH1699.1 [28] 郑佳锋, 刘黎平, 曾正茂, 等. Ka波段毫米波云雷达数据质量控制方法研究. 毫米波与红外学报, 2016, 35(6): 748-757. https://www.cnki.com.cn/Article/CJFDTOTAL-HWYH201606018.htmZheng J F, Liu L P, Zeng Z M, et al. Ka-band millimeter wave cloud radar data quality control. J Infrared Millim Waves, 2016, 35(6): 748-757. https://www.cnki.com.cn/Article/CJFDTOTAL-HWYH201606018.htm [29] 梁海河, 张沛源, 葛润生. 多普勒天气雷达风场退模糊方法的研究. 应用气象学报, 2002, 13(5): 591-601. doi: 10.3969/j.issn.1001-7313.2002.05.008Liang H H, Zhang P Y, Ge R S. Study of data processing of wind fields from Doppler radar. J Appl Meteor Sci, 2002, 13(5): 591-601. doi: 10.3969/j.issn.1001-7313.2002.05.008 [30] 崔哲虎, 程明虎, 乌秋力, 等. 快速中值滤波方法及其在Doppler雷达资料处理中的应用. 高原气象, 2005, 24(5): 727-733. doi: 10.3321/j.issn:1000-0534.2005.05.011Cui Z H, Cheng M H, Wu Q L, et al. A technique of fast median filtering and its application to data quality control of Doppler radar. Plateau Meteorology, 2005, 24(5): 727-733. doi: 10.3321/j.issn:1000-0534.2005.05.011 [31] 刘丽. 东南沿海污染气象特征及生物气溶胶的扩散模拟研究. 南京: 南京大学, 2011.Liu L. Study on the Pollution Meteorological Characteristics and Simulation of Bioaerosols Dispersion over Southeast Coastal Area of China. Nanjing: Nanjing University, 2011. [32] 吕立慧, 刘文清, 张天舒, 等. 基于激光雷达的京津冀地区大气边界层高度特征研究. 激光与光电子学进展, 2017, 54(1): 50-56.Lü L H, Liu W Q, Zhang T S, et al. Characteristics of boundary layer height in Jing-Jin-Ji Area based on lidar. Laser & Optoelectronics Progress, 2017, 54(1): 50-56. [33] 蒋德海, 王成刚, 吴兑, 等. 利用风廓线雷达资料对广州地区边界层日变化特征的分析研究. 热带气象学报, 2013, 29(1): 129-135. https://www.cnki.com.cn/Article/CJFDTOTAL-RDQX201301016.htmJiang D H, Wang C G, Wu D, et al. Diurnal variation of atmospheric boundary layer over Wushan station, Guangzhou using wind profiler radar. Journal of Tropical Meteorology, 2013, 29(1): 129-135. https://www.cnki.com.cn/Article/CJFDTOTAL-RDQX201301016.htm -
计量
- 摘要浏览量: 1400
- HTML全文浏览量: 351
- PDF下载量: 160
- 被引次数: 0
