Ground Radar Method for Measuring Precipitation Under Complex Relief Conditions

It is well known that the radar reflectivity of the precipitation zone Z is related to the intensity of precipitation I. The heavier the precipitation, the higher its reflectivity. The presence of such a relationship makes it possible to determine both the very fact of the presence of precipitation and its intensity from the measured Z values. By measuring the intensity of precipitation at different points in time, it is possible to calculate the amount of precipitation. The error of radar measurement of precipitation amounts can be easily determined by comparing radar readings with data from ground-based precipitation gauges. In this case, the data of the precipitation gauge are taken as “true” and are, as it were, reference. Recently, a large amount of work has been done to compare the intensities and amounts of precipitation measured by contact (precipitation network) and remote (radar) methods. It was found that along with good matches, there were significant differences in precipitation parameters. This is due to the large heterogeneity of precipitation and the previously unknown parameters of the Z–I ratio. Therefore, radar data is usually corrected by ground data. To reduce errors in radar measurements of precipitation, such measurements are made as close as possible to the Earth's surface, at a level of 0.5–1.0 km. However, in conditions of rough terrain in the mountains and foothills, this condition often cannot be met.