Meteorological Echo And Non-Meteorological Echo Recognition Study Of CINRAD

Radar echoes can be divided into non-meteorological echo and meteorological echo. Non-precipitation echo of meteorological echo will have a certain impact on precipitation; On the one hand, rather than let radar information on pollution, and non-meteorological goals lead to radar data quality issues; On the other hand, some non-meteorological echo can also derive a useful meteorological information. So to achieve echo classification real-time of radar data, have generated significant to radar data quality control and in the lower reaches of the radar products. This article is based on fuzzy logic of the existing identification clutter, develop the clutter identification methods suited to CINRAD (SA), use Beijing and Tianjin SA radar information, at the same time using the reflection and radial velocity, and a wide spectrum of processing, analysis the characteristics of the non-meteorological echo and meteorological echo, and then to clutter identification; CSI(critical success index)is used to improve the membership function of clutter identification, and probe the clear-air echo and sea echo on the characteristics. This work is for launching of CINRAD base-data quality control, radar product quality, as well as non-meteorological echo inversion characteristics of the atmosphere, and so on to provide a strong foundation.(1) Use Beijing and Tianjin SA radar information, at the same time using the reflection and radial velocity, and a wide spectrum of processing, obtain the various features of membership function of precipitation Echo and clutter, and analysis of the various functions; results also show that features echo and precipitation echoes have different characteristics, that is, six parameters such as MDVE, SDVE, MDSW, TDBZ, GDBZ SPIN have a clear distinction between precipitation and clutter echo, using these six parameters can inversion the characteristics of clutter and precipitation echo and then to identified.(2) Taking into account the membership function is the key precision of the clutter identify, the use of CSI evaluation criteria to determine the optimal linear trapezoidal membership functions for fuzzy logic to identify anomalous propagation clutter.(3) In the analysis of contribution of radial velocity to echo recognition, you can see, the radial velocity is good for radar echoes identify, the integrated use of radar echo intensity, radial velocity and wide spectrum can make radar echo Recognition accuracy rate increase; and after results test found that its impact mainly embodied on precipitation in the identification, the radial velocity parameters involved in the identification can reduce the precipitation misjudgment.(4) In the case of analysis the misjudgment of rainfall also showed that on the edge of heavy rainfall echo and the stratiform clouds precipitation echo, the mistaken identification was mainly attributed by the level changes of echo intensity and speed, When speed parameters not involved in identifying, the possibility of mistaken identification increase. These are the captions that the echo recognition of the use of radial velocity data can improve the effectiveness of identification result.(5) In analysis of the AP sea echo in Xiamen in the case, can be seen its characteristics be similar to AP ground echo, but there are also some obvious differences, such as compared to the AP ground echo ,The high probability areas of vertical changes of sea echo is lightly larger than the ground echo, this will cause sea echo membership function curve of the vertical changes to the right of the ground echo, and the level changes of the sea echo is slightly smaller than ground echo, its membership function curve will to the left of ground echo, and radial velocity showed that the high probability area of the sea echo in the negative zone is slightly wider than the ground echo; the scope of the variance of speed of sea echo is within the ground echo, wide spectrum of features is slightly wider than the ground Echo.(6) In the case studies of clear-air layered echo in the Beijing area shows that the cloud layer clear-air echo located in atmospheric boundary layer, the main scattering mechanism suit for the Prague scattering with turbulence-scale ofλ/2. The emergence of boundary layer clear-air echoes, shows that the boundary layer is in a large high temperature, pressure, wet the uneven structure, the gradient turbulent process caused by temperature, pressure and water vapor.(7) At the same time, we should also know that radar identification is still a complicated issue, rely only on forecasters and radar data, sometimes to accurately distinguish between clutter and precipitation echo is very difficult, but the identification of various echoes is very significant, therefore, further development of comprehensive utilization of satellite and radar data for the recognition of clutter, sea and clear-air echo is very necessary.