This paper dwells upon optimizing the azimuth samp-ling interval of digital surface maps used to model radar ground clutter.The resulting equations can be used to find the digital map sampling interval for the require...This paper dwells upon optimizing the azimuth samp-ling interval of digital surface maps used to model radar ground clutter.The resulting equations can be used to find the digital map sampling interval for the required calculation error and modeled power of the simulated signal,which determines the resulting distribution of backscatter intensity.The paper further showcases how the sampling interval could be increased by pre-processing the map.展开更多
Using China New Generation Weather Radar （CINRAD） level-Ⅱ data, the original algorithms for removing isol-ated non-meteorological echoes and ground clutters in radar data, which have been applied to Weather Surveil...Using China New Generation Weather Radar （CINRAD） level-Ⅱ data, the original algorithms for removing isol-ated non-meteorological echoes and ground clutters in radar data, which have been applied to Weather Surveillance Radar-1988 Doppler （WSR-88D） in the USA and Severe Weather Automatic Nowcast （SWAN） system in China, are modified and improved. To remove isolated non-meteorological echoes, the new algorithm introduces a constraint parameter （Po） to distinguish whether a window of 5 x 5 points is isolated as external echoes. A statistical analysis of 150 radar scans （5 cases, with each case comprising 30 scans） under three different echo types （small-scale convec-tion, typhoon, and large-scale synoptic system） shows that the constraint parameter Po ≤ 0.167 is suitable for remov- ing isolated non-meteorological echoes while preserving the edge of meteorological echoes. A new parameter, NDZ, which promotes the ability of the algorithm to identify the ground clutters appearing at two adjacent elevation angles, is constructed based on the vertical continuity of reflectivity. These improved algorithms are tested for four cases （three cases of isolated non-meteorological echoes and one case of ground clutters）. Based on the statistics of 232 volume scans of radar data （on a temporal resolution of 1 h） measured at Nanchang station from 0000 UTC 5 to 1600 UTC 14 March 2015, it is found that the improved algorithms not only eliminate most （over 95% under clear-sky conditions） of the isolated non-meteorological echoes and ground clutters （including those appearing at two adjacent elevation angles）, but also well preserve the structure of meteorological echoes （storms）.展开更多
A novel clutter suppression method in ground penetrating radar （GPR） is proposed. The preliminary result is obtained by using target resolution improved processing （TRIP）. The preliminary result will be used as an...A novel clutter suppression method in ground penetrating radar （GPR） is proposed. The preliminary result is obtained by using target resolution improved processing （TRIP）. The preliminary result will be used as an initial input for TRIP iteration. All TRIP iteration steps are the adaptive linear combination of the previous TRIP result and the preliminary result. This adaptive combination strategy can balance clutter suppression and target information protection, which is considered as a troublesome contradiction and a chronic problem in clutter suppression research. When the matrix entropy of iteration result converges, the algorithm can achieve a good result both in clutter suppression and target protection. Experimental results demonstrate that the new algorithm outperforms the existing approaches.展开更多
基金supported by the Russian Foundation for Basic Research(19-37-90103).
文摘This paper dwells upon optimizing the azimuth samp-ling interval of digital surface maps used to model radar ground clutter.The resulting equations can be used to find the digital map sampling interval for the required calculation error and modeled power of the simulated signal,which determines the resulting distribution of backscatter intensity.The paper further showcases how the sampling interval could be increased by pre-processing the map.
基金Supported by the Jiangxi Provincial Department of Science and Technology project(20171BBG70004)Open Project of the State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences(2016LASW-N11)National Natural Science Foundation of China(41575098)
文摘Using China New Generation Weather Radar （CINRAD） level-Ⅱ data, the original algorithms for removing isol-ated non-meteorological echoes and ground clutters in radar data, which have been applied to Weather Surveillance Radar-1988 Doppler （WSR-88D） in the USA and Severe Weather Automatic Nowcast （SWAN） system in China, are modified and improved. To remove isolated non-meteorological echoes, the new algorithm introduces a constraint parameter （Po） to distinguish whether a window of 5 x 5 points is isolated as external echoes. A statistical analysis of 150 radar scans （5 cases, with each case comprising 30 scans） under three different echo types （small-scale convec-tion, typhoon, and large-scale synoptic system） shows that the constraint parameter Po ≤ 0.167 is suitable for remov- ing isolated non-meteorological echoes while preserving the edge of meteorological echoes. A new parameter, NDZ, which promotes the ability of the algorithm to identify the ground clutters appearing at two adjacent elevation angles, is constructed based on the vertical continuity of reflectivity. These improved algorithms are tested for four cases （three cases of isolated non-meteorological echoes and one case of ground clutters）. Based on the statistics of 232 volume scans of radar data （on a temporal resolution of 1 h） measured at Nanchang station from 0000 UTC 5 to 1600 UTC 14 March 2015, it is found that the improved algorithms not only eliminate most （over 95% under clear-sky conditions） of the isolated non-meteorological echoes and ground clutters （including those appearing at two adjacent elevation angles）, but also well preserve the structure of meteorological echoes （storms）.
基金supported by the National Natural Science Foundation of China under Grant No. 40976114the National 863 Program under Grant No. 2008AA121702-3
文摘A novel clutter suppression method in ground penetrating radar （GPR） is proposed. The preliminary result is obtained by using target resolution improved processing （TRIP）. The preliminary result will be used as an initial input for TRIP iteration. All TRIP iteration steps are the adaptive linear combination of the previous TRIP result and the preliminary result. This adaptive combination strategy can balance clutter suppression and target information protection, which is considered as a troublesome contradiction and a chronic problem in clutter suppression research. When the matrix entropy of iteration result converges, the algorithm can achieve a good result both in clutter suppression and target protection. Experimental results demonstrate that the new algorithm outperforms the existing approaches.
