利用2007年6月和2008年6—7月国内 GPS 探空仪同步比对试验数据及2010年中国阳江国际探空系统比对试验数据，基于现有的探空仪随机误差的间接计算方法，深入分析不同的探空原始数据平滑处理程度对随机误差评估的影响。分析表明：现有的探空仪随机误差评估方法不能完全适用于秒级探空数据，特别是对风、平流层温度和对流层相对湿度这3个要素的随机误差的评估。在同步比对施放中，如果对探空原始数据的平滑处理程度一致，可以利用现有的随机误差评估方法，不会产生明显偏差；反之，如果平滑处理程度差异较大，则间接计算得出的随机误差会明显偏大。在比对施放方案中，为了更好地获取某种型号探空仪的随机误差，建议将多个同型号探空仪同球施放进行比对观测，避免作为参考仪器的其他型号探空仪自身的误差参与计算，影响待测探空仪随机误差的评估。同型号探空仪同球施放的探空仪越多，获取的有效统计数据越多，随机误差的分析越准确。%With the development of science and technology,the performance of sounding system,including the data acquisition rate,accuracy,reliability and automation are improved significantly.Comparison and sta-tistical methods to estimate various errors are also needed to be improved.Relative system error and ran-dom error are concern variables of the sounding information users,errors evaluated by the reasonable method can reflect typical characteristics of error to same extent.So far,there have not a satisfactory standard radiosonde developed as a reference,relative system error and random error are obtained only through direct intercomparison simultaneously.The random error,it is not determined by dual-launching the same type of radiosondes because of the heavy workload.It is mainly used the indirect estimation meth-od,that is the random error of the specify instrument used as a reference,and then the random error of unknown radiosonde is isolated from the variance between reference and unknown radiosondes.But wheth-er the indirect calculation method of random error is suitable for the second level sounding data or not,the further discussion should be adopted.An overview of the random error is explained including the definition and determination method.And then two datasets are used to analyze the effect on the random error by different degree of data smoothing.One is the data of domestic GPS radiosondes comparison experiments in June 2007 and June-July 2008,the other dataset is the 8th WMO radiosonde comparison at Yangjiang China in 2010.The intercomparison analysis shows that the indirect calculation method of random error could not fully be applicable to the second level sounding data,especially for the estimation of random er-ror of wind,temperature in stratospheric and relative humidity in tropospheric.The second level sounding data can detect the more detail caused by the swing of rising balloon,the raw data should be smoothed to reduce the impact of the above.If smoothing degrees of the original data compared are consistent,the indi-rect calculation method of random errors could be used suitably.The deviation is small,conversely,it might be problematical,which will produce large bias if it exists the difference in smoothing degree of the original data.In the scheme of direct intercomparision,in order to obtain the relative system error and ran-dom error of the different types of radiosonde systems,it is best to hang more than one of the same types of radiosonde in the same balloon to contrast synchronously,which can reduce the influence on evaluating the unknown radiosonde random error because of the own error of reference instrument.The more radio-sondes of the same type are used,the more valid data could be obtained,the more accurate evaluation of random errors could be obtained.
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