Accuracy of Sonic Anemometers: Laminar Wind-Tunnel Calibrations Compared to Atmospheric In Situ Calibrations Against a Reference Instrument
Accuracy of Sonic Anemometers: Laminar Wind-Tunnel Calibrations Compared to Atmospheric In Situ Calibrations Against a Reference Instrument
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声波风速计的精度：层流风洞校准与参考仪器的大气原位校准的比较
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
A. Smedman
中科院分区：
文献类型：
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作者：
U. Högström;A. Smedman
两台 Gill Solent 超声波风速计（型号 1012R2 和 1210R3）针对基于风向标的热膜风速计（带有额外的温度和湿球温度传感器）、MIUU（MIUU：乌普萨拉大学气象研究所）仪器进行了现场并行测量测试。层流风洞测试显示，该仪器在大气湍流中使用时仍能保持其精度。这与两个声波风速计的观察结果形成鲜明对比，这两个声速风速计首先在层流风洞流中进行校准。构建了单独的三维校准矩阵，结果表明，对于所有方位角和±40°以内的迎角，风速的剩余校准不确定度可降低至 0.4-0.8%。在声波学与 MIUU 仪器的现场比对测试中，发现不仅平均风速的精度，而且所有研究的二阶矩（方差和协方差，有温度和无温度）的精度通常下降了三到四倍。大多数散射似乎是随机的，但就风速而言，也发现了对风向的明显依赖性。结论是，对 R2 和 R3 仪器的垂直支撑杆效应的校正在层流中几乎完全一致，但在自然湍流中效果并不完全令人满意。反过来，这很可能是因为圆柱形支撑杆后面的尾流对进场流的特征高度敏感。
Two Gill Solent Ultrasonic anemometers, models 1012R2 and 1210R3, weretested in field parallel measurements against a windvane based hot-film anemometerwith additional sensors for temperature and wet-bulb temperature, the MIUU (MIUU:Meteorology Institute, Uppsala University) instrument. This instrument was shown toretain its precision from laminar wind-tunnel tests when used in atmospheric turbulentflow. This contrasts strongly to the observed results for the two sonic anemometers,which were first calibrated in laminar wind-tunnel flow. Individual three-dimensionalcalibration matrices were constructed, and were shown to reduce the remaining calibration uncertainty for the wind speed to 0.4–0.8% for all azimuths and for angles of attack within ±40°. In the field intercomparison tests of the sonics against the MIUU instrument, it was found that the precision not only of the mean wind speed but of all second-order moments studied (variances and covariances, with and without temperature) deteriorated by a factor of typically three to four. Most of the scatter appears to be random, but in the case of the wind speed, a clear dependence on wind direction is found as well. It is concluded that the correction for the effect of the vertical supporting rods of the R2 and R3 instruments, which gives nearly perfect agreement for laminar flow, does not work entirely satisfactory in the natural turbulent flow. This, in turn, is likely to be so because of high sensitivity of the wake behind the cylindrical supporting rods to the character of the approach flow.