讨论了电离层对星载SAR矩形包络线性调频信号的影响 ,推导出由电离层引起的图像偏移和峰值二次相位误差的计算公式 ,基于这些公式对P ,L ,C 3个波段的影响作了比较分析。结果表明 :电离层对P波段的影响很大 ,对L波段有一定影响 ,对C波段的影响基本可以忽略。

Ionospheric effects on linear FM rectangular envelope signals of space-borne SAR are considered in this paper. Two kinds of effects due to the ionosphere are presented and the relative formulas are derived, including compressed pulse shift and second phase error. It can be seen that the compressed pulse shift is proportional to total electron content (TEC) and inverse proportional to the square of signals frequencies,and that the second phase error is proportional to TEC and the square of signals bandwidth while in inverse proportional to the square of signals frequencies at the same time. The ionospheric effects at P, L, C bands are also investigated by comparison based on the formulas derived above. The result shows that signals at P-band will be severely affected by the ionosphere. The effects will be obvious at L-band if the signals have a large bandwidth or TEC values are high. At C-band, ionospheric effects are neglectable.