采用风廓线雷达5波束探测模式的数据对测风精度进行评估分析,用垂直波束和其中两个相邻倾斜波束的探测数据构成一对计算因子,通过对同一距离高度上的4对计算因子进行误差分析,评估风廓线雷达的测风精度,得到水平风在垂直指向连续高度上的精度.对北京延庆CFL-08风廓线雷达2010年3,6,9,12月4个典型代表月份逐日连续探测资料进行了处理分析,结果表明:该雷达满足风速误差不大于1.5m·s-1、风向误差不大于10°探测精度要求的最大探测高度6月、9月为8 km,3月、12月为6 km,基本符合该雷达探测高度的设计要求.信噪比、大气风场的不均匀性是影响雷达测风精度的主要因素:信噪比影响了高空的测风精度,-15 dB可以作为判断雷达测风可信数据最大探测高度的阈值；晴空大气出现的风场不均匀性对风廓线雷达的测风精度影响不大,降水出现时环境风场不均匀性造成水平风向、风速的测量误差较大,不能满足测风精度要求,特别是对流性降水发生前的1～2 h,水平风向、风速的方差增长迅速,可以作为强降水出现的预警指标.%merits of the discharge process in triggered lightning are observed synthetically. The characteristics of induced voltages produced by triggered lightning on power lines and signal lines of an automatic weather station are measured and analyzed. The triggered lightning technique is also used to test the detection efficiency and precision of lightning location system in Guangdong Province. The peak current of return stoke (RS) ,the transferred charge within 1 ms after the RS beginning, the half-peak width and the 10%-90% risetime for RS waveform are recorded and analyzed. The relationship between the luminosity of the lightning channel and the continuous current intensity during the initial stage and interval of the return strokes for triggered lightning flashes is analyzed. The results reveal that, on the whole, luminosity of the air-ionized part of lightning channel shows obvious positive correlation with current. Linear correlation exists between square root of integrated luminosity and current when the luminosity of lightning channel doesn't reach saturation in the high-speed images. However, the parameters in the fitting equation are slightly distinct for different processes. The 2D propagation speed of upward positive leader for the triggered lightning is about 104-105 m o s‐1. The speed of downward negative leader involved in altitude triggered lightning is about 105 m o s‐1. The information on the shape and velocity of the leader channel provided by the high-speed camera records and the synchronous electrical field change data are used to calculate the charge densities and current of upward positive leader for the triggered lightning. The results indicate that, prior to disintegration of the wire, the charge densities of the upward positive leaders range from several micro-coulombs to hundreds of micro-coulombs per meter, and the distribution of charge densityis strongly skewed toward the upward positive leader tips. The calculated current in the upward positive leaders ranges from less than one to dozens of amperes, and increases with the ongoing propagation of the leader. The induced voltage pulse caused by the RS on the overhead power tine appears as a positive peak initially and then declines sharply, followed by a negative peak, with a period of several microseconds between the positive and negative peaks. The maximum negative and positive peaks of the bipolar induced voltages on the power line are -10. 31 kV and 4. 47 kV, respectively. The voltage associated with the fast-changing pulses superposed on the continuous current following the return strokes can exceed 1 kV. The waveform of voltage on the signal for wind speed shows the peak pulses resembled a "V" shape. The results of the lightning location system in Guangdong report that the flash and stroke detection efficiency are 92% and 45% for rocket-triggered lightning, respectively. The space location error ranges from 111 to 5250 m with a mean space location error of 759 m. The relative error between peak current estimated by LLS and the direct measured current from the channel bottom of artificial triggered lightning is 16. 3%.
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