Assessment of OTT Pluvio2 Rain Intensity Measurements
Assessment of OTT Pluvio2 Rain Intensity Measurements
复制标题
OTT Pluvio2 降雨强度测量的评估
DOI：
10.1175/jtech-d-19-0219.1
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发表时间：
2021
影响因子：
2.2
通讯作者：
Testik, Murat C.
中科院分区：
文献类型：
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作者：
Saha, Rupayan;Testik, Firat Y.;Testik, Murat C.
本研究探讨OTT Pluvio 2称重式雨量器的随机和系统误差成分，以及在实验室条件下随时间变化的降雨强度（RI）的测量的稳定性。在实验中使用了提供恒定和时变RI的高度精确的可编程蠕动泵。评价RI值的突然、逐步和周期性变化。RI读数是在真实的时间（RT）中以不同的时间分辨率（6-60 s）获取的，RI范围为6-70 mm h-1。我们的分析表明，OTT Pluvio 2实时RI测量的下限应重新定义为1分钟分辨率下的7 mm h− 1。给出了包含95%重复测量的容许区间，概率为0.95。结果表明，在折射率范围内，测量方差不等，测量重复性不均匀。对于7和8 mm h−1的RI值，观察到统计学显著的负偏倚，而不存在统计学显著的线性问题。通过使用统计控制限，它表明，RI测量的平均值稳定的实际RI值。对RT桶重测量的详细调查显示，桶重测量存在时间延迟，这会导致动态降雨条件下报告的RI测量结果出现显着误差。为了证明Pluvio 2的实时RI测量的大误差的潜力，开发了一套方程，忠实地再现了Pluvio 2的内部（隐藏）算法，并从动态实验室和原位降雨情景的结果进行了模拟。这项调查的结果表明，修改目前的Pluvio 2 RI算法，以提高其性能的必要性，并显示后处理现有的Pluvio 2 RI数据集，以提高测量精度的可能性。
This study investigates the OTT Pluvio2weighing precipitation gauge’s random and systematic error components as well as stabilization of the measurements on time-varying rainfall intensities (RI) under laboratory conditions. A highly precise programmable peristaltic pump that provided both constant and time-varying RI was utilized in the experiments. Abrupt, gradual step, and cyclic step changes in the RI values were evaluated. RI readings were taken in real time (RT) at different time resolutions (6–60 s) for the RI range of 6–70 mm h−1. Our analysis indicates that the lower threshold for the OTT Pluvio2’s real-time RI measurements should be redefined as 7 mm h−1at a 1-min resolution. Tolerance intervals containing 95% of the repeated measurements with a probability of 0.95 are given. It is shown that the measurement variances are unequal over the range of RI and the measurement repeatability is not uniform. A statistically significant negative bias was observed for the RI values of 7 and 8 mm h−1, while there was not a statistically significant linearity problem. Through the use of statistical control limits, it is shown that means of the RI measurements stabilized on the actual RI value. A detailed investigation on RT bucket weight measurements revealed a time delay in bucket weight measurements, which causes notable errors in reported RI measurements under dynamic rainfall conditions. To demonstrate the potentiality of large errors in Pluvio2’s real-time RI measurements, a set of equations was developed that faithfully reproduced the Pluvio2’s internal (hidden) algorithm, and results from dynamic laboratory and in situ rainfall scenarios were simulated. The results of this investigation show the necessity of modifying the present Pluvio2RI algorithm to enhance its performance and show the possibility of postprocessing the existing Pluvio2RI datasets for improved measurement accuracies.