基于粒子滤波的雷达检测前跟踪算法，建立新的目标模型和观测模型，提出了线性扩展目标。能够检测1db的弱小目标。-A radar target track-before-detect (TBD) algorithm using particle filter (PF) is presented in this paper. System dynamic model and measurement model are established based on a sequence of radar range-Doppler measurements using the new algorithm. Furthermore, a linear xtended target model is proposed, which is more capable of describing a maneuvering target than the conventional point arget model. The likelihood ratio function of the new model is also derived in this paper. Due to the accumulation of the PF-TBD over time and the effectiveness of the proposed target model, an mproved

probability of detection for dim target is obtained. The experimental imulations demonstrate that the proposed method is capable of detecting and tracking a target with SNR of 1 dB robustly.