Kinematic Structure of a Heavy Rain Event from Dual-Doppler Radar Observations

The detailed kinematic structure of a heavy rain event that occurred in the middle reaches of the Yangtze River was investigated using dual-Doppler radar observation. A variational analysis method was developed to obtain the three-dimensional wind fields. Before the analysis, a data preprocessing procedure was carried out, in which the temporal variation with the scanning time interval and the effect of the earth curvature on the data position were taken into account. The analysis shows that a shear line in the lower and middle levels played an important role in the rainfall event. The precipitation fell mainly on the south end of the shear line where southerly flow prevailed and convergence and updraft were obvious. With the movement and decay of the shear line, the precipitation moved and decayed correspondingly.

A Model Study of Three-Dimensional Wind Field Analysis from Dual-Doppler Radar Data

A three-dimensional wind field analysis sollware based on the Beigng-Gucheng dual-Doppler weather radar system has been built, and evaluated by using the numerical cloud model producing storm flow and hydrometeor fields. The effects of observation noise and the spatial distribution of wind field analysis error are also investigated.

Three-Dimensional Wind Field Retrieved from Dual-Doppler Radar Based on a Variational Method:Refinement of Vertical Velocity Estimates

In this paper,a scheme of dual-Doppler radar wind analysis based on a three-dimensional variational method is proposed and performed in two steps.First,the horizontal wind field is simultaneously recovered through minimizing a cost function defined as a radial observation term with the standard conjugate gradient method,avoiding a weighting parameter specification step.Compared with conventional dual-Doppler wind synthesis approaches,this variational method minimizes errors caused by interpolation from radar observation to analysis grid in the iterative solution process,which is one of the main sources of errors.Then,through the accelerated Liebmann method,the vertical velocity is further reestimated as an extra step by solving the Poisson equation with impermeable conditions imposed at the ground and near the tropopause.The Poisson equation defined by the second derivative of the vertical velocity is derived from the mass continuity equation.Compared with the method proposed by O’Brien,this method is less sensitive to the uncertainty of the boundary conditions and has better stability and reliability.Furthermore,the method proposed in this paper is applied to Doppler radar observation of a squall line process.It is shown that the retrieved vertical wind profile agrees well with the vertical profile obtained with the velocity–azimuth display(VAD)method,and the retrieved radial velocity as well as the analyzed positive and negative velocity centers and horizontal wind shear of the squall line are in accord with radar observations.There is a good correspondence between the divergence field of the derived wind field and the vertical velocity.And,the horizontal and vertical circulations within and around the squall line,as well as strong updrafts,the associated downdrafts,and associated rear inflow of the bow echo,are analyzed well.It is worth mentioning that the variational method in this paper can be applied to simultaneously synthesize the three-dimensional wind field from multiple-Doppler radar observations.

The Use of Dual-Doppler Radar Data in the Study of 1998 Meiyu Frontal Precipitationin Huaihe River Basin

During the Meiyu period in June and July of 1998, intensified field observations have been carried out for the project “Huaihe River Basin Energy and Water Cycle Experiment (HUBEX)”. For studying Meiyu front and its precipitation in Huaihe River basin, the present paper has performed analysis on the middle and lower level wind fields in the troposphere by using the radar data obtained from the two Doppler radars located at Fengtai district and Shouxian County. From June 29 to July 3 in 1998, the continuous heavy precipitation occurred in Huaihe River basin around Meiyu front. The precipitation process on July 2 occurred within the observation range of the two Doppler radar in Fengtai district and Shouxian County. The maximum rainfall of the Meiyu front was over 100 mm in 24 h, so it can be regarded as a typical mesoscale heavy precipitation process related to Meiyu front. Based on the wind field retrieved from the dual Doppler radar, we find that there are meso-γ scale vertical circulations in the vertical cross-section perpendicular to Meiyu front, the strong upward motion of which corresponds to the position of the heavy rainfall area. Furthermore, other results obtained by this study are identical with the results by analyzing the conventional synoptic data years ago. For example: in the vicinity of 3 km level height ahead of Meiyu front there exists a southwest low-level jet; the rainstorm caused by Meiyu front mainly occurs at the left side of the southwest low-level jet; and the Meiyu front causes the intensification of the low-level convergence in front of it. Key words Dual Doppler radar - Meiyu front - Meso—γ scale vertical circulation This research was supported by Project HUBEX (Project Number: 49794030) which is funded by the National Natural Science Foundation of China (NSFC).

STRUCTURE OF MESO-β AND –γ-SCALE ON SOUTH CHINA HEAVY RAINFALL ON 12～13 JUNE 2005 USING DUAL-DOPPLER RADAR

The three-dimensional wind fields of the heavy rain on 12-13 June 2005 in Guangdong province are retrieved and studied with the volume scan data of the dual-Doppler radar located in the cities of Meizhou and Shantou. It is shown that the meso-β-scale and meso-γ-scale convergence lines located in the convective system at the low and middle layer play an important role in the heavy rainfall. The convergence line is the initiating and maintaining mechanism of the rain. A three dimensional kinematic structure model is also given.

Mesoscale Structure of Rainstorm Retrieved from Dual-Doppler Radar Observations Using the 4DVAR Assimilation Technique

The four-dimensional variational （4DVAR） data assimilation method was applied to dual-Doppler radar data about two Meiyu rainstorms observed during CHeRES （China Heavy Rain Experiment and Study）. The purpose of this study is to examine the performance of the 4DVAR technique in retrieving rainstorm mesoscale structure and to reveal the feature of rainstorm mesoscale structure. Results demonstrated that the 4DVAR assimilation method was able to retrieve the detailed structure of wind, thermodynamics, and microphysics fields from dual-Doppler radar observations. The retrieved wind fields agreed with the dual- Doppler synthesized winds and were accurate. The distributions of the retrieved perturbation pressure, perturbation temperature, and microphysics fields were also reasonable through the examination of their physical consistency. Both of the two heavy rainfalls were caused by merging cloud processes. The wind shear and convergence lines at middle and lower levels were their primary dynamical characteristics. The convective system was often related to low-level convergence and upper-level divergence coupled with up- drafts. During its mature stage, the convective system was characterized by low pressure at lower level and high pressure at upper level, associated with warmer at middle level and colder at lower and upper levels than the environment. However, a region of cooling and high pressure occurred in the lower and middle levels compared to warming and low pressure in the upper level during its dissipating ＇.stage. The water vapor, cloud water, and rainwater corresponded to the convergence, the updraft and the intensive reflectivity, respectively.

Study on Retrieving Three-Dimensional Wind Using Simulated Dual-Doppler Radar Data in the Cartesian Space

This paper investigates a technique of retrieving three-dimensional windfields from the dual-Doppler weather radar radial wind which is based on the Cartesian space usingvariational method. This technology provides a simultaneous resolution of three wind components andsatisfies both the minimal dual-equation system and the continuity equation. The main advantage ofthis method is that it can remove the potential drawback of an iterative solution of Cartesiandual-Doppler analysis techniques which is a major demerit when one retrieves the vertical velocityusing mass continuity equation with iterative method. The data pre-processing technology andinterpolation are also studied. This work developed a three-dimensional Cressman weighting functionto process the interpolation. In order to test the capability and advantage of this method, onenumerical experiment based on simulating dual-Doppler radar observations is designed. Firstly, wesynthesize the dual-Doppler radar radial velocity and reflectivity from the numerical model. Then,the three-dimensional wind components are retrieved from the radial velocity and reflectivity usingthis technique. The retrieved three-dimensional wind fields are found to be quite consisted withthose previously simulated wind fields. Mean difference, root-mean-square error, and relativedeviation are defined to test the precision of the method. These statistic errors reveal theaccuracy and the advantage of this method. The numerical experiment has definitely testified thatthis technique can be used to retrieve the three-dimensional wind fields from the radial velocityand reflectivity detected by the real dual-Doppler weather radar.

中低纬度系统相互作用过程的中尺度风场分析

以山东济南和滨州两部S波段多普勒雷达的观测数据为基础,采用直接合成的方法,反演台风“利奇马”和西风槽相遇引发极端降水过程的中尺度系统三维风场。(1)冷暖空气交汇产生的切变线长时间维持是西风槽与台风相互作用过程中产生极端降水的关键,暖空气先进后退,表现为东南气流和西北气流先后越过雷达站,垂直方向出现复合切变;(2)最强上升运动出现在对流单体回波梯度最大的区域,最大下沉运动出现在回波顶下风方,中低层回波中心均为弱风速区;(3)发展中的对流单体各层均有气旋式入流,成熟的对流单体高层出流有反气旋式出流;(4)风垂直切变是雨团降水增幅的主要影响因素,成熟期的雨团具有低质心对流单体风暴的结构形态,垂直运动达到最强。

双能CT联合彩色多普勒超声诊断宫颈癌淋巴结转移的临床价值

目的:探讨双能CT参数联合彩色多普勒超声(彩超)对宫颈癌盆腔淋巴结转移的诊断价值。方法:选择2019年6月-2022年6月在本院确诊的155例宫颈癌患者临床资料,根据病理诊断是否发生盆腔淋巴结转移分为未转移组108例和转移组47例。分析患者双能CT参数及彩超表现特征,评价双能CT参数联合彩超对宫颈癌盆腔淋巴结转移的诊断效能。结果:转移组47例中,彩超诊断宫颈癌淋巴结转移41例(87.2%),表现为类圆形或融合状不规则形,内部均匀低回声,可见丰富的点、条状血流信号,RI值较低;未转移组108例中,彩超诊断未发生淋巴结转移86例(79.6%),未见明显占位性病变,内部呈回声、稍低回声,血流不丰富,RI值较高。155例宫颈癌患者病灶内部CT表现为低回声、不均匀,多数边缘不规则,部分内部可见钙化灶,淋巴结呈圆形或椭圆形,边缘模糊,强化明显,中心呈低密度。转移组动、静脉期双能CT定量参数λHU、NIC、IC均高于未转移组(P<0.05);λHU、NIC、IC诊断宫颈癌淋巴结动脉期转移的曲线下面积(AUC)动脉期(0.831、0.818、0.836)略高于静脉期(0.800、0.772、0.721),彩超诊断宫颈癌淋巴结转移的AUC为0.834,灵敏度87.2%、特异度79.6%,动脉期λHU、NIC、IC联合彩超诊断宫颈癌淋巴结转移的AUC为0.963,灵敏度93.6%、特异度89.8%,联合诊断效能高于单独检测(P<0.05)。结论:动脉期双能CT参数联合彩超对宫颈癌盆腔淋巴结转移有较高的诊断价值。

基于S波段双偏振雷达融化层识别算法的研究

基于融化层识别算法(melting layer detection algorithm,MLDA)原理,利用2020年7—8月济南、青岛两部S波段双偏振多普勒雷达体扫数据,进行融化层高度信息识别试验,根据试验结果在MLDA算法中引入径向连续性检验、增加扫描仰角范围与调整判别融化层出现的距离库总数阈值的改进措施,与改进前的MLDA算法进行了对比分析,得到以下结论:MLDA对融化层顶高度有一定识别效果,识别的融化层顶高度的平均绝对误差较大,融化层底高度过低;加入径向连续性检验(简称MLDA-R1)后,识别的融化层顶高度的平均绝对误差明显减小,融化层底对应温度与融化层厚度分布在合理区间,但是遗漏识别的试验数明显增加;在MLDA-R1基础上,扫描区域增加了3.3°仰角(简称MLDA-R2)并调整了判别融化层出现的距离库总数阈值(简称MLDA-R3),融化层遗漏识别的试验数明显减少,同时提高了对融化层高度信息的识别效果;一些降水回波与非降水回波混合的区域会被错误识别为融化层区域,影响MLDA算法对融化层的识别效果,仍需进一步改进。总体来看,改进后的MLDA更适用于我国S波段双偏多普勒振雷达,对雷达水凝物相态分类与定量降水估测等气象现代化业务有一定支撑作用。

利用双偏振参量估计降水粒子下落末速度及三维风场反演的应用

降水系统三维风场反演的关键问题之一是准确地估算降水粒子下落末速度(W_(t)),为了探究双偏振雷达估计W_(t)的能力,利用广东省龙门地区的雨滴谱数据,建立了W_(t)与S和X波段双偏振雷达观测量的关系,并且将其应用于广州和韶关两部雷达的风场反演。对华南地区2019年4月发生的一次飑线过程进行风场反演试验,分析讨论了此次飑线过程的风场结构配置,并探索了利用不同方法估算的W_(t)在反演出的风场结构上的差异。结果表明:S和X波段雷达通过回波强度(Z H)和差分反射率(Z DR)估算W_(t),其函数形式为幂函数和一次函数,通过Z DR估算的W_(t)均方根误差相较利用Z H估算的W_(t)均方根误差更小、相关系数更大,因此通过Z DR估算的W_(t)的效果更好。此次飑线过程主要从西北向东南方向发展,风场主要是西风和西南风,在飑线前部弓状回波区域内存在明显的辐合区,垂直结构是低层辐合、高层辐散。对比利用不同方法估算W_(t)得到的三维风场,其水平风场变化主要集中在±1 m·s^(-1)的范围,水平经向风速的变化(Δu)主要是正值,水平纬向风速的变化(Δv)主要是负值,垂直方向上风速的变化(Δw)集中在±0.15 m·s^(-1)内,主要是正值,低层Δu、Δv、Δw较高层小。研究结果为降水系统三维风场反演及垂直速度反演提供了参考依据。

双路偏振结构的激光多普勒测速系统

为了消除光束倾角带来的不确定性,本文建立了一种双路偏振式激光多普勒测速系统。该系统使用双光束双探头结构来探测物体的运动信息。首先,通过转动实验精确获得双光束间的夹角大小,对于任意光束倾角,本文采用双探头装置收集运动物体表面的散射光束,结合双路偏振式光路结构,得到两路干涉信号的多普勒频移。然后,创新性采用了细化分帧算法对两路干涉信号进行实时解调,通过两路速度分量的合成得到物体真实速度。实验结果表明:速度在10 mm/min~1500 mm/min范围内,测量值与理论值之间的平均误差可以达到1%~5%。在非平稳运动过程中,通过细化分帧算法修正后的v-t图像RMSE均值为1.19 mm/min。该系统结构满足速度测量的稳定可靠、精度高、抗干扰能力强等要求。

双多普勒雷达观测在一次雹云结构中的应用

利用常州站和泰州站双多普勒天气雷达探测数据,结合常规观测资料和ERA5再分析资料,综合分析了2019年7月6日一次强对流天气过程的天气形势、雷达回波强度演变特征和双多普勒雷达反演的三维流场信息。重点利用双多普勒雷达径向速度资料反演出格点流场,并结合回波特征分析雹云的结构。结果表明:强对流天气过程中,江苏受高空冷涡影响,在高空冷槽、高空急流、低层切变线和地面辐合线的配置条件下,形成了上干冷、下暖湿的层结不稳定结构。本次过程中,雹云不仅具有典型的强对流单体雷达回波特征,在中层强回波中心处,还有明显的“S”型水平流场结构。雹云的低层,是明显的辐合与旋转配置的水平流场。深厚的零线结构是成雹的典型特征。

复杂水下环境中的Dual-HFM速度谱优化

在理想环境下,双双曲调频(dual hyperbolic frequency modulation,Dual-HFM)速度谱估计方法可得到高分辨率的连续多普勒估计结果。然而由多径、双目标环境引起的旁瓣干扰,削弱了速度谱方法抑制噪声的能力,影响目标参数估计。针对该方法在多径、双目标等各种复杂水声环境中的应用,进行了深入的讨论,推导了多径、双目标造成的速度谱旁瓣位置,并提出了基于多帧信号的速度谱旁瓣抑制方法,利用另一维度信号空间中目标回波信息与多径杂波旁瓣的差异性,抑制了复杂水下环境中的速度谱旁瓣,并保留了速度谱计算量低的优点。通过数值仿真验证了所提方法的适用性,为低信噪比、多径、双目标环境下的多普勒估计提供了理论依据。

一次飑前降雹超级单体分裂过程的雷达回波及流场特征分析

2019年4月23日浙江南部发生一次明显的超级单体分裂过程,为研究超级单体风暴分裂特征,利用多部雷达构成的双雷达三维风场反演组网技术,结合雷达基本产品、风廓线雷达及探空资料对此次分裂过程做了分析。该超级单体风暴在较强的风垂直切变环境下(地面—500 hPa大于15 m/s)发生,形成于飑线主体弓形回波前端,具有明显的三体散射特征且持续时间较长。分裂从初始风暴的北侧中层开始,然后迅速向上、下伸展,左移超级单体具有明显的中反气旋涡旋结构,呈现由悬垂、强回波柱、强上升气流配合构成的典型超级单体结构,与右移超级单体无论在形态或是流场结构上都形成近似镜像对称的特征。在两者即将分离时,两风暴均发生了降雹,对应强下沉气流。在新风暴分裂形成的发展阶段其垂直廓线中最大垂直速度和最大负散度均在增大,而对应时段原风暴这两个物理量数值减小;整个分裂过程两个风暴正、负涡度数值均一同逐渐增大,气旋—反气旋涡旋的旋转程度变大趋势一致。低层风垂直切变矢量随高度上升逆时针旋转,分裂的左移反气旋超级单体加强发展,右移的气旋式超级单体受到一定抑制,与理论研究结论一致。该个例雷达反演的风场特征与径向速度分布吻合,反演风场基本可靠,为直观理解超级单体风暴分裂的动力学特征提供了进一步参考。

2022年3月14日江西及周边地区冰雹回波特征分析

为更好地开展对江西冰雹天气的监测预警工作,使用MICAPS数据、自动站数据、雷达拼图数据、雷达PUP产品数据、双多普勒雷达反演风场数据、冰雹灾情照片视频和微信冰雹信息反馈等资料,采用天气学、雷达气象学等原理与方法,对2022年3月14日江西及周边省份冰雹回波特征进行分析,结果表明:3月14日,江西及周边省份多地出现冰雹,20个区域站出现≥17.2 m·s^(-1)的大风,24个区域站出现≥50.0 mm的降水,且雷暴大风和冷空气大风混合出现。200 hPa高空出流区、500 hPa南支槽和风速切变、850 hPa低涡和切变线、地面辐合线和西南倒槽是冰雹天气主要系统;南昌订正后较大的CAPE、较强逆温层、中层干区和低层湿区为冰雹天气发生提供了环境条件。冰雹以超级单体回波为主,有时孤立存在,有时存在于回波群、回波带之中;回波强度≥60 dBz,强回波面积最小≥18 km^(2),最大≥180 km^(2);30~60 dBz强回波梯度距离≤6 km,具有明显的云砧前伸回波;冰雹回波生命史多数在2 h以上。在冰雹回波识别中,垂直积分液态水含量(VIL)是一个很重要的特征。江西冰雹单部雷达VIL在35~60 kg·m^(-2),雷达拼图上VIL为35~50 kg·m^(-2)。在冰雹回波2.5 km CAPPI图上,冰雹回波强度均≥60 dBz,最大可达65 dBz;在双多普勒雷达反演风场上多数回波中心具有中涡旋结构、侧面辐合风场、南北风场辐合等特征;有些个例风场比较凌乱。上述分析结果为江西冰雹天气的监测预警提供了分析依据。

中青年髋部骨折患者术前深静脉血栓形成的危险因素及列线图预测模型的构建

目的 分析中青年髋部骨折患者术前深静脉血栓形成(DVT)的危险因素,并构建列线图预测模型。方法 选取首次确诊髋部骨折的中青年患者共408例,根据术前双功能彩色多普勒超声检查(DUS)结果分为DVT组60例和无DVT组348例。比较2组临床资料和血生化指标;采用多因素Logistic回归分析筛选危险因素,并构建列线图模型。结果 单因素分析发现,相比于无DVT组,DVT组年龄更大,低能量损伤增多,受伤至DUS时间和总住院时间延长,血清总蛋白<60 g/L、白蛋白<35 g/L、乳酸脱氢酶(LDH)≥250 U/L、红细胞(RBC)计数<4.0×10^(12)/L、血红蛋白(Hb)<110 g/L、红细胞压积(HCT)≥50%、血小板计数≥300.0×10^(9)/L和D-二聚体≥0.5 mg/L的患者比率较高,差异均有统计学意义(P<0.05)。多因素Logistic回归分析显示,年龄大、受伤至DUS时间长、LDH≥250 U/L、D-二聚体≥0.5 mg/L和HCT≥50%是术前DVT发生的独立危险因素(P<0.05)。采用R软件建立列线图模型,总分220分。受试者工作特征(ROC)曲线计算列线图预测DVT的曲线下面积(AUC)为0.897,大于各单一危险因素的AUC,差异有统计学意义(P<0.05)。Hosmer-Lemeshow检验显示,列线图的拟合优度良好(χ^(2)=1.625,P=0.342)。校正曲线显示,列线图预测DVT的发生概率与实际DVT发生率有较好的一致性。结论 中青年髋部骨折患者也有一定的术前DVT发生率,年龄大、受伤至DUS时间长、LDH≥250 U/L、D-二聚体≥0.5 mg/L和HCT≥50%是影响术前DVT发生的独立危险因素。构建列线图模型用于指导术前筛查高风险DVT患者有较好的应用潜力。

基于卫星与双极化多普勒天气雷达的湖南中部地区一次极端暴雪应用分析

基于风云二号卫星红外云顶亮温(TBB)资料和双极化多普勒天气雷达资料,并结合区域自动气象站观测数据、NCEP再分析数据,对2022年2月22—23日湖南发生的极端暴雪过程进行诊断分析。结果表明:(1)一条维持在成熟阶段的西南—东北向云带中镶嵌的中β尺度云团持续经过形成类似列车效应的传播,是造成本次极端暴雪过程的主要原因,极端暴雪落区主要位于TBB<-30℃冷云团边缘梯度最大处。(2)双极化多普勒天气雷达相关系数、反射率因子以及差分反射率等产品,对融化层高度以及大气中降水粒子属性的识别和判断均有较好的指示性,其中相关系数为0.80~0.97,基本符合融化层特征。(3)多普勒雷达风廓线产品对雨雪相态转变以及降雪加强有一定指示意义,该产品能反映出降雪发生前2.4 km高度形成的稳定垂直风切变,以及降雪加强时1.2 km高度东北急流增强、3 km高度西南急流增强、2.4 km高度垂直风切变增大,其中2.4 km高度垂直风切变稳定持续十多个小时为此次极端暴雪过程提供了有利于不稳定层结建立与维持的动力条件,而此次过程雨雪转换快且积雪深度大主要是降雪前期低层较为干冷所致。

济宁S波段双线偏振多普勒雷达数据质量分析

以济宁S波段双线偏振多普勒雷达观测的层状云降水资料为例,分析了信噪比(signal-to-noise ratio,SNR)、相关系数(ρhv)对偏振参量的影响以及近距离双偏振参数的特征。利用雷达最高扫描仰角的层状云降水资料,对小雨和干雪两种自然目标物差分反射率因子(ZDR)的订正效果进行分析。研究表明:(1)SNR小于21 dB时,ZDR、ρhv、差分传播相位偏差(ΔΦDP)的平均值和标准差随SNR的变化波动明显,ZDR、ρhv、差分传播相位(ΦDP)不稳定,数据质量差。SNR大于21 dB时,ZDR、ρhv、ΦDP才具有可信度,且随着SNR的增大,ZDR、ρhv、ΦDP的稳定性越来越好。(2)SNR大于21 dB、ρhv<0.965时,ΔΦDP的平均值和标准差随ρhv的变化而波动剧烈;SNR大于21 dB、ρhv>0.965时,ρhv越大,ΦDP的值越稳定。(3)受地面噪声干扰、近距离地物以及天线旁瓣的影响,0~15 km的近距离偏振参数不稳定,数据质量差,业务应用中需特别注意。(4)利用小雨和干雪两种自然目标物对ZDR系统误差进行标定,通过对比发现,小雨粒子的ZDR系统误差的平均值和标准差比干雪粒子小很多,且小雨粒子ZDR系统误差订正曲线比干雪粒子稳定;小雨粒子相比于干雪粒子,其ZDR系统误差订正效果更稳定;经过系统误差订正后的降水粒子的ZDR值较订正前更加合理。

双多普勒雷达风场反演误差和资料的质量控制

提出了用双多普勒雷达观测资料进行回波强度、径向速度和方位定位的质量控制方法 ,以及利用概率分布法订正配对的双多普勒雷达回波强度的方法。以 2 0 0 1年 973“中国暴雨”外场试验期间获取的双多普勒雷达观测资料为例 ,比较了合肥、马鞍山和宜昌、荆州的两对双多普勒雷达同步观测的回波强度、径向速度和方位的改变对观测数据对比的影响 ;分析了这两对双多普勒雷达径向速度测量误差引起的风场反演的误差。结果表明 :两对双多普勒雷达观测的回波强度和径向速度的空间位置和变化趋势比较一致 ,合肥与马鞍山雷达的回波强度有一定差异 ,径向速度也有 1～ 2m/s的差异。风场反演的误差与风场的方向、大小、空间位置等有关。在两个径向速度夹角在 40°～ 1 40°范围内 ,共面上的风场的反演误差在 1～ 2倍的雷达探测径向速度的误差范围内。