| Popis: |
The speckle pattern in the image plane of the burst illumination imaging lidar system is characterized by the intensity correlation function. This speckle pattern, specific to coherent laser light, has two origins: the target roughness and the turbulence perturbation. We propose a model which takes into account both of them. For a non turbulent atmosphere, we find the classic speckle pattern given by Goodman. With a turbulent atmosphere, the perturbation along the forward and backward paths may be coupled or independent. In the coupled turbulence perturbation case, the collected intensity is amplified and the target scintillation is filtered by the receiver. For the independent turbulence perturbation case, the analysis is restricted here to a diffraction-limited atmosphere-lens system and two limiting cases are distinguished: the far-field and near-field assumptions. |
