基于精确相差测向的机载多普勒频移计算

Calculating of Airborne Doppler Shift Based on Accurate Phase Difference DF

摘要: 首先描述了利用一维双基阵所导出的精确测向式，然后基于多普勒频移方程，通过简单的角度置换即获得了基于相差测量的频移计算式。和基于相差近似测向式所给出的频移计算式的比较表明，基于精确相差测向式所导出的频移计算式是更为准确的。误差分析表明，当基线长度为几十个波长时，在目标到达角小于40度的范围内，多普勒频移的测量误差可小于5赫兹。

Abstract: Firstly, the derivation process of an accurate DF formula based on one-dimensional linear array with two baselines is described. Then, the Doppler shift formula based on phase difference measuring is obtained by simple substitution for angle according to Doppler shift equation. As compared with the Doppler shift formula derived from approximative DF formula based on phase difference measuring, the one derived from accurate DF formula is more veracious. Error analysis shows that the measurement error of Doppler shift is less than 5 Hz within arrival angle range  when baseline is about dozens of wavelengths.