Comparison And Verification Of Data From GPM Spaceborne Dual-frequency Precipitation Radar And Ground-based C-band Dual-polarization Radar

The combined application of ground-based radar and spaceborne radar has a great prospect,but due to the difference of scanning mode and detection band,the data detected by them are quite different.The comparison of reflectivity factor and precipitation between ground-based C-band dual-polarization radar(Nuist-C)and dual-frequency precipitation radar(DPR)can better understand the characteristics of their detection data and the essential reasons for the difference between the two detection data,and make preparation for the data fusion.By comparing the reflectivity factor data and precipitation data detected by DPR and Nusit-C during 2015 and 2017,the results show that :(1)For the reflectivity factor,the overall consistency of the reflectivity factor detected by DPR and Nuist-C is well and the deviation is small,the main factor causing the deviation are the attenuation and the different backscattering cross section caused by different wavelength.After attenuation correction and band correction,the correlation coefficient of reflectivity factor between DPR NS and Nuist-C reaches 0.86,and the correlation coefficient of reflectivity factor between DPR HS and Nuist-C reaches 0.83.Analyse the differences of reflectivity factor between DPR and Nuist-C based on the types of hydrometeors,the DPR NS has a good correlation to detect the echo of wet snow,graupel,large drop and moderate rain,a low correlation to detect the echo of dry snow,and a poor correlation to detect the echo of heavy rain and ice crystal.DPR HS has a good correlation to detect the echo of big drop and moderate rain,a low correlation to detect the echo of dry snow,wet snow and graupel,and a poor correlation to detect the echo of heavy rain and ice crystal.(2)For the precipitation,take the precipitation by the adaptive optimization algorithm as a standard to assess DPR precipitation products,the overall consistency of precipitation detected by DPR and Nuist-C is well,a small part of precipitation detected by DPR is overestimated,the main sources of deviation of precipitation detected by DPR are precipitation with strong intensity,convective precipitation and precipitation with wrong phase state identification.(3)The precipitation detected by different modes of DPR are different,compared with DPR NS and DPR HS,the DPR MS has the best consistency with Nuist-C,and the number of abnormal minimum value of precipitation is the least.DPR NS and DPR MS are better than DPR HS in detecting convective precipitation,and DPR HS and DPR MS are better than DPR NS in detecting stratified precipitation.DPR MS can improve the detection ability of weak and moderate precipitation on the basis of ensuring the detection ability of heavy precipitation.For non-liquid precipitation(snow/graupel),DPR HS has a stronger ability to detect snow/graupel hydrometeors precipitation than DPR NS.The main reason for the difference between DPR NS,DPR HS and DPR MS in detecting precipitation is the different detection bands.