| （英） |
SAR (Synthetic Aperture Radar) has an image reproduction method similar to the backprojection method typified by computer tomography, and various studies have been conducted since its commercialization. Since the backprojection method in computer tomography increases the projected energy density as it gets closer to the origin of rotation, a filtered backprojection method that removes this characteristic has been studied, and several applications to the radar field have also been investigated. Some studies have been conducted on its application to the radar field. Since general computer tomography does not assume a linear orbit but a rotational orbit, there are areas where the effects of this assumption have not yet been investigated. In the present study, it is feared that the energy density after image reconstruction based on linear orbits, as typified by SAR, will increase with the squint angle because the change in the squint angle to the observation target is small compared to the change in the distance along the linear orbit, especially for observations with a large squint angle. On the other hand, the larger the squint angle is, the larger the distance to the observation target becomes, which is expected to have the opposite effect of reducing the energy density. In this paper, the effect of the improvement of energy density by linear orbit observation is observed from a theoretical study based on the Jacobian and numerical simulation, respectively, and the effect of distance change during observation is also reported, assuming a Ka band SAR that can be constructed in a dark room. |