雷达脉冲频率估计的高精度与实时性是衡量电子情报侦察系统性能的关键指标,但现代雷达越来越小的脉冲宽度和脉冲重复周期对电子侦察系统的高精度瞬时频率估计带来挑战。提出了一种实用的常规雷达脉冲信号频率估计快速算法,该算法利用快速傅立叶变换算法分别实现电子侦察接收机单通道数据的正交变换、频率粗估计及交叉分区判别,再利用非线性最小二乘算法实现高精度的频率估计。仿真试验与实测数据验证了该快速算法的有效性与正确性,同时也验证了该算法具有计算量小、实时性高、精度高等特点。
The real-time performance and high precision for instantaneous frequency(IF) estimation of radar pulse signal are the key indexes to measure the capacity of Electronic Intelligent (ELINT)System. But the pulse width and pulse repetition interval (PRI)of modern radar signal are getting smaller, which pose challenges for ELINT. A practical and fast IF estimation algorithm is proposed in the paper. Using FFT, the fast algorithm aceomplishs quadrature transform, coarse IF estimation and cross-sections discrimination, respectively. Then a refinement step is followed by nonlinear least square method for achieving fine IF estimation. Simulation result and real data demonstrate the efficacy of the proposed fast IF estimation algorithm, pos- sessing small computation, high real-time performance and high precision.