Anotace:
Electromagnetic (EM) wave of enemy radar propagated by troposcatter can be utilized for beyond line-of-sight (b-LoS) location. To provide theoretical basis for passive troposcatter location system, channel characteristics including propagation loss, refraction effect and multipath fading are analyzed. Ray tracing method improved by tropospheric model is employed to describe the refraction effect. Correlation coefficient on the basis of transfer function is deduced to evaluate multipath fading. According to troposcatter characteristics, maximum operating range is estimated, cooperative energy detection is introduced to copy with the received signal without priori knowledge. The principle and accuracy of location algorithm based on azimuth is researched. Spatial smoothing is introduced under the situation that uncorrelated and coherent signals coexist. Through analyzing consequences, future directions for developing are suggested.