A Technical Evaluation of Lidar-Based Measurement of River Water Levels
A Technical Evaluation of Lidar-Based Measurement of River Water Levels
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DOI：
10.1029/2019wr026810
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发表时间：
2020-04-01
影响因子：
5.4
通讯作者：
Sah, Neeraj
中科院分区：
文献类型：
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作者：
Paul, Jonathan D.;Buytaert, Wouter;Sah, Neeraj
测量河流水位（水位）是流量估算和洪水预报等各种应用的关键。虽然有各种各样的原位和非接触方法，但迫切需要新的和更具成本效益的方法。快速的技术进步加速了非接触方法的使用和飞行时间距离传感器的发展。在现有的技术中，使用激光雷达进行距离测量是有前途的，因为它成本低，能量效率高，测量占地面积小。然而，激光雷达很少用于测量水位。在这里，我们测试近红外（905 nm）激光雷达传感器，以确定其适用于阶段的测量范围内的环境条件。使用不同的实验室和现场设置，我们评估传感器的性能作为测量距离，表面粗糙度，空气温度，水浊度和测量角度的函数。尽管水对红外辐射的反射率很低，但我们发现，测试的传感器能够在所有测试条件下进行测量，最高可达到40度的入射角。传感器的精度在设备的技术规格范围内，其特征在于相对误差约为0.1%。我们发现传感器温度的准确性，我们归因于次优的内部补偿的电子产品的强烈依赖。传感器的精度随着测量距离的增加而降低，随着水体表面粗糙度的增加而增加。我们没有发现任何显着的影响，水浊度的测量。关键点我们描述了一个新的非接触激光雷达原型测量河流水位原型可以采取测量范围内的环境条件，以类似的35米的范围，并接近40度的倾斜激光雷达有潜力，以丰富观测数据库中的数据稀缺地区的全球
Measuring river water level (stage) is key for a variety of applications including discharge estimation and flood prediction. Although a variety of in situ and noncontact methods are available, there is an urgent need for new and more cost-efficient methods. Rapid technological progress has accelerated the use of noncontact methods and development of time-of-flight distance sensors. Among available techniques, the use of lidar for distance measurement is promising because of its low cost, high energy efficiency, and small measurement footprint. However, lidar has rarely been used to measure water levels. Here we test a near-infrared (905 nm) lidar sensor to determine its suitability for stage measurements under a range of environmental conditions. Using different laboratory and field setups, we assess sensor performance as a function of measurement distance, surface roughness, air temperature, water turbidity, and measurement angle. Despite the low reflectivity of water for infrared radiation, we find that the tested sensor is able to take measurements under all tested conditions, up to an incidence angle of similar to 40 degrees. The accuracy of the sensor is within the technical specifications of the device and is characterized by a relative error of around 0.1%. We find a strong dependence of the accuracy on sensor temperature, which we attribute to suboptimal internal compensation of the electronics. The precision of the sensor decreases with increasing measured distance and increases with surface roughness of the water body. We did not find any significant impact of water turbidity on the measurements.Key PointsWe describe a new noncontact lidar prototype to measure river water level The prototype can take measurements under a range of environmental conditions, to similar to 35 m range, and to inclinations of similar to 40 degrees Lidar has the potential to enrich the observational database in data-scarce regions globally