Snowfall estimates using snowfall phenomena under the lower-atmosphere area

为了估计降雪量（降雪量少），我们从雪云中测量了雪颗粒落在地面附近的降雪过程。结果如下：1。垂直方向电磁波反射回波的测量它在富山国立理工大学的电力大楼屋顶安装了一个小型雷达（微型雨雷达，由METEK制造）。观测了从春季到秋季的降雨现象，并测量了降雨率。从2002年12月开始连续观测到冬季降雪现象。利用电子秤分析了电磁波反射回波与降雪率的关系。从雷达反射系数观察到每个高度都有下降现象。功率谱用α和ε在γ分布函数处进行近似，并根据这些参数对降雪模式进行分类。利用图像处理技术测量降雪粒子的形状和质量，利用落在观测塔上的降雪粒子观测图像。测量雪粒的密度是可能的。根据粒径与速度的关系，可以对雪粒的种类（冰雹和雪花）进行分类。雷达降雪率测量系统根据1和2的关系，利用两个雷达参数计算降雪率和估计降水种类。我们将这些测量数据和分析结果整合到数据库中，并编制了降雪估计因子。该技术不仅可以定量观测降雪，而且可以测量固体降水的种类和质量。

To estimate amount of snowfall (snowfall rare), we measured the snowfall process that snow particles fall near the ground from the snow cloud. The results were given as follows.1. Measurement of the electromagnetic wave reflection echo in the vertical directionIt installed a small radar (Micro rain radar, made from METEK) in Toyama National College of Technology, the electric building rooftop.It observed a rainfall phenomenon from the spring to the fall and rainfall rate were measured. The winter snowfall phenomenon was continuously observed from December, 2002.We analyzed the relation between the electromagnetic wave reflection echo and the snowfall rate using an electronic balance. It was observed a falling phenomenon from the radar reflection factor in every altitude. The power spectrum was approximate at the gamma-distribution function using α and ε and it classified a snowfall pattern in these parameters.2. Measurement the shape and the quality of a snowfall particle by the image processing techniqueIt observed an image by the snowfall particle which falls in the observation tower. It was possible to measure the density of snow particle. It becomes able to classify of the snow particle kind (hail and snowflake) from the relation between the diameter and the velocity.3. Snowfall rate measurement system by the radarForm 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. We integrated these measurement data and an analysis result into the data-base and prepared a snowfall estimate factor. This proposed technique is not only useful to observe snowfall quantitatively, but also to measure the kind and quality of solid precipitation.