ENLARGING SAR PATCH-MAPPING AREA BY ANTENNA BEAM SCAN

通过天线波束扫描扩大 SAR区域成像范围(英文)

The approach for enlargement of SAR patch mapping area by antenna beam scan is investigated, which serves for moderate fine-resolution mapping of medium-sized terrain patches. The scanning angular velocity and the scanning angular scope are determined respectively. The angular velocity of the scanning antenna is controlled to scan over just one azimuth 3 dB beam width in the time interval during which the radar platform moves over one synthetic aperture length determined from the desired cross-range resolution, radar wavelength, nominal slant range, and squint angle. The scanning angular scope is mainly determined by the azimuth width of the terrain patch, nominal slant range, squint angle, platform velocity, and azimuth beam width. Finally, the related experimental results of an airborne SAR are presented. The linear range-Doppler algorithm is employed in image formation after motion compensation is conducted to remove the effect of transnational motion of the radar platform relative to the map center.

研究通过天线波束扫描扩大 SAR区域成像范围的方法 ,以适应较大区域中等分辨率成像的要求。推导了天线扫描角速度、角度范围与所需成像范围和方位分辨率的关系。选择天线扫描角速度 ,使得在一个合成孔径时间内 ,波束恰好扫过 3分贝波束宽度 ,而合成孔径长度由要求的方位分辨率、波长、斜距和斜视角决定。天线扫描角度范围由要求的成像区方位宽度、斜距、斜视角、载机速度和波束方位宽度决定。最后 ,介绍了某机载 SAR试飞得到的成像结果。在运动补偿之后 。