CAJ | 학술논문

地形起伏特征是影响海上雷达探测性能的重要因素.基于幂级数多项式拟合、三角函数的FFT和一级Daubechies小波分解的理论分析以及数字地形的数值仿真,结果表明:FFT近似地形的精确程度与坡度取决于横向距离谱宽度,距离谱越窄,地形坡度越小,但地形失真也越严重;一级Daubechies小波分解地形的精度最高,且在整个横向距离内坡度均小于10°～15°.小波分析方法有效消除了海上复杂地形的刃形结构,极大地扩展了大气波导环境中基于修正抛物型方程进行精确数值分析的雷达探测范围.
지형기복특정시영향해상뢰체탐측성능적중요인소.기우멱급수다항식의합、삼각함수적FFT화일급Daubechies소파분해적이론분석이급수자지형적수치방진,결과표명:FFT근사지형적정학정도여파도취결우횡향거리보관도,거리보월착,지형파도월소,단지형실진야월엄중;일급Daubechies소파분해지형적정도최고,차재정개횡향거리내파도균소우10°～15°.소파분석방법유효소제료해상복잡지형적인형결구,겁대지확전료대기파도배경중기우수정포물형방정진행정학수치분석적뢰체탐측범위.
The characteristics of the marine digital terrain(DT)has an significant impact on the radar detection ability.Based on the polynomial fitting of power$eries,FFT of sinusoidal function and 1-level decomposition of Daubechies wavelet,the simulation shows that the approximation of DT and the gradient depend on the width of horizontal distance spectrum.Wider distance spectrum causes smaller gradient,but results badly in the DT distortion.Daubechies wavelet decomposition can provide the more precise terrain,and the gradient of the horizontal distance is wholly less than 10°～15°.The method of wavelet analysis effectively realizes the knife-edge clearance of marine digital terrain,and greatly broadens the radar detection range for the modified parabolic equation.