低空目标探测中的大气折射误差快速算法
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摘要
为了利用雷达对低空和超低空飞行器进行精确探测,必须对影响雷达测量精度的大气折射误差进行实时修正。针对目前大气折射误差计算存在处理时间较长、不能满足实时性要求的现状,提出了一种利用虚高进行折射误差修正的快速算法。根据等效地球半径中电波射线为直线的情形推出计算接近目标真实高度的虚高方法,利用虚高将折射误差公式中的积分项分为两部分,最影响折射误差修正处理时间的部分采用一次积分完成,另一小部分利用变步长的迭代方法完成。仿真实验表明,在保证与目前公认高精度的射线描迹法相同的精度条件下,利用虚高进行大气折射误差修正可实现快速计算,计算速度至少提高一倍,且计算速度随雷达仰角的增大而增快。
In order to use radar to accurately detect the low and very low-altitude aircraft,the atmospheric refraction error which influences the measurement accuracy of radar must be corrected in real-time.Taking into account of the current situation that the calculation of atmospheric refraction error needs longer time and cannot meet real-time requirement,this paper proposes a fast algorithm by using virtual-height method to modify the refraction error.Regarding the radio wave ray as straight line in earth's equivalent radius,the virtual-height method which can calculate the close height with the true altitude is derived.By using virtual-height the integral terms of refraction error formula can be divided into two parts.One part that has a strong impact on the treatment time of refraction error modification can be calculated by one time integration and the other part can be calculated by variable step iterative method.The simulation results show that the computation time of virtual-height method can reduced by half under the condition of the same precision as the high precision ray tracing method,and the speed gets faster with the radar's elevation angle increasing.
In order to use radar to accurately detect the low and very low-altitude aircraft,the atmospheric refraction error which influences the measurement accuracy of radar must be corrected in real-time.Taking into account of the current situation that the calculation of atmospheric refraction error needs longer time and cannot meet real-time requirement,this paper proposes a fast algorithm by using virtual-height method to modify the refraction error.Regarding the radio wave ray as straight line in earth's equivalent radius,the virtual-height method which can calculate the close height with the true altitude is derived.By using virtual-height the integral terms of refraction error formula can be divided into two parts.One part that has a strong impact on the treatment time of refraction error modification can be calculated by one time integration and the other part can be calculated by variable step iterative method.The simulation results show that the computation time of virtual-height method can reduced by half under the condition of the same precision as the high precision ray tracing method,and the speed gets faster with the radar's elevation angle increasing.
引文
[1]张瑜.电磁波空间传播[M].西安:西安电子科技大学出版社,2007.
[2]刘波,刘宝泉,陈春晖.机载预警雷达测高精度分析[J].雷达科学与技术,2012,10(2):133-137.LIU Bo,LIU Baoquan,CHEN Chunhui.Altitude Measurement Precision Analysis of Airborne Early Warning Radar[J].Radar Science and Technology,2012,10(2):133-137.(in Chinese)
[3]JIANG Changyin,WANG Beide.Atmospheric Refraction Corrections of Radiowave Propagation for Airborne and Satellite-Borne Radars[J].Science in China:Technological Sciences,2001,44(3):280-290.
[4]张捍卫,栾军,雷伟伟.大气折射的原理性公式[J].地球物理学进展,2014,29(2):616-619.
[5]祝转民,李恒年,黄永宣,等.电波折射误差修正的精确模型与在线算法[J].系统工程与电子技术,2003,25(3):287-289,325.
[6]武征,潘佳梁,胡梦中.测量雷达对流层大气折射误差修正方法研究[J].无线电工程,2014,44(2):73-76.
[7]赵乐至,武昱,唐佩佳,等.雷达大气折射误差修正快速算法[J].四川兵工学报,2012,33(5):104-111.
[8]马东升,董宁.数值计算方法[M].3版.北京:机械工业出版社,2015.
[9]史水娥,杨豪强.电波折射误差快速修正方法[J].河南师范大学学报(自然科学版),2012,40(4):168-171.
[10]杨豪强,朱命怡,张瑜.等效地球半径的等效性与局限性研究[J].河南师范大学学报(自然科学版),2008,36(6):66-69.
[2]刘波,刘宝泉,陈春晖.机载预警雷达测高精度分析[J].雷达科学与技术,2012,10(2):133-137.LIU Bo,LIU Baoquan,CHEN Chunhui.Altitude Measurement Precision Analysis of Airborne Early Warning Radar[J].Radar Science and Technology,2012,10(2):133-137.(in Chinese)
[3]JIANG Changyin,WANG Beide.Atmospheric Refraction Corrections of Radiowave Propagation for Airborne and Satellite-Borne Radars[J].Science in China:Technological Sciences,2001,44(3):280-290.
[4]张捍卫,栾军,雷伟伟.大气折射的原理性公式[J].地球物理学进展,2014,29(2):616-619.
[5]祝转民,李恒年,黄永宣,等.电波折射误差修正的精确模型与在线算法[J].系统工程与电子技术,2003,25(3):287-289,325.
[6]武征,潘佳梁,胡梦中.测量雷达对流层大气折射误差修正方法研究[J].无线电工程,2014,44(2):73-76.
[7]赵乐至,武昱,唐佩佳,等.雷达大气折射误差修正快速算法[J].四川兵工学报,2012,33(5):104-111.
[8]马东升,董宁.数值计算方法[M].3版.北京:机械工业出版社,2015.
[9]史水娥,杨豪强.电波折射误差快速修正方法[J].河南师范大学学报(自然科学版),2012,40(4):168-171.
[10]杨豪强,朱命怡,张瑜.等效地球半径的等效性与局限性研究[J].河南师范大学学报(自然科学版),2008,36(6):66-69.