Development of a snowfall estimate system using two Doppler radars

为了估计降雪现象，我们测量了降雪过程，雪粒子从雪云落到近地面。研究结果如下：1.用图像处理技术测量降雪粒子的质量我们观测了落在塔中的降雪粒子的直径和速度。从这些数据中计算出雪颗粒的质量和平均密度。可以测量雪颗粒的质量。2.垂直方向的电磁波反射回波的测量在富山国立工业大学的电气大楼屋顶安装了两台小型雷达（METEK公司生产的Micro rain radar）。可以使用两个雷达观测冬季降雪现象。功率谱用两个参数近似于伽玛分布函数，并按降雪模式分类.同时测量系统和数据库的构建同时测量1和2。我们将这些测量数据和分析结果集成到数据库中。根据1和2之间的关系，可以利用这两个雷达参数计算降雪率和估计降水类型.雷达反射率的相关性分析对各高度雷达反射率之间的相关性进行了估计。这是可能的，以估计到达的时间，雪粒子落在地面上的云。

To estimate snowfall phenomena, we measured snowfall process that snow particles fell near the ground from snow clouds. The results were given as follows.1. Measurement of the quality of snowfall particles by an image processing techniqueWe observed the diameter and velocity of snowfall particles which fell in a tower. It was calculated the mass and average density of a snow particle from these data. It was possible to measure the quality of snow particles.2. Measurement of electromagnetic wave reflection echoes in the vertical directionWe installed two small radars (Micro rain radar, made from METEK) in Toyama National College of Technology, the electric building rooftop. It was possible to observe winter snowfall phenomenon using two radars. The power spectrum was approximate at the gamma-distribution function using two parameters and classified in a snowfall pattern.3. Simultaneous measurement system and database constructionIt was simultaneously measured 1 and 2. We integrated these measurement data and analysis results into the database. From the relation between 1 and 2, it was possible to calculate the snowfall rate and estimate the kind of precipitation using the two radar parameter.4. Correlation analysis of radar reflectivityWe estimated the correlation analysis between the radar reflectivity in every height. It was possible to estimate the arrival time which snow particles fell on the ground from clouds.