Real time synchronously integrated technique for radar and raingauge based on concept of quasi-same rain volume sample

The real time synchronously integrated technique for radar and raingauge (R&G) based on the concept of quasi same rain volume sample was presented. Because of the presence of temporal and spatial discrepancies as well as resolution differences, the same sample correspondence of R&G has long been a difficult, lasting problem. However, the observations indicate that there exists the correlation conforming to the power law between hourly accumulation of raingauge measurement QG and radar detected echo aloft over the rain gauge vertically (ZOH). On the basis of this fact, aiming to eliminate the temporal and spatial discrepancies, the concept of quasisame rain volume sample and the five direct correspondence relationships of R&G are built up. The quite convenient and practical TIVS, i.e. time integral vertical synchronous sampling, and its ZOH-QG relationship with power law are emphatically studied. What has significance is that under the fixed exponent, the coefficient A B or AM can flexibly vary in accordance with the temporal and spatial variability of the natural precipitation, and has a function to synchronously integrate the Z-R conversion and the gauge adjustment into a single equation, thus the precipitation estimation error caused by detecting resolution differences between radar and gauge can be obviously mitigated. It is apparently different from the traditional methods wherein precipitation is estimated by radar and gauge, respectively. The real time synchronously integrated technique using the ZOH-QG relationship to estimate hourly ground rainfall accumulation, is called radar gauge synchronously integrated method (RASIM). The experiments of two cases show that the correctness rate for area estimation within 230 km is about 90% and the average relative error rate for point estimation over the whole process is about 20%.Through the analysis of effects for various wind drifts in three kinds of environment fields, the physical substance of TIVS has been revealed, definitely suggesting that it is an approximate quasi-sample rain volume sampling. Fortunately, by full demonstration, the better availability has been explained in most weather conditions and confirmed by experimental tests in the paper. By analyzing the data pairs of R&G, the effective quality control method is established which can greatly improve the stability and the reasonability of ZOH-QG relationship. The forecasting product of hourly accumulated precipitation derived by RASIM method has been put into the operational forecasting and has especially played an important part in the short term quantitative monitoring and forecasting for torrential rain.RASIM needs to be further studied at many aspects, such as to establish more robust theory concerning with quasi same sample for R&G, to try searching the methods of accurately temporal and spatial coordinating sampling, to make tests and analysis in field for TIVS in various weather systems and conditions, to explore the data quality control technique influenced by wealth systems and its mechanism of evolution, to study the further application of fixed exponent in calculation of rainfall accumulation, to study multiple ZOH-QG relationships and the characters and application of A B ( AM) distribution in space, and so on. All these advances will prospectively help to improve the correctness of radar estimated rainfall accumulation.