Azimuth Phase Center Adaptation on Transmit for High-Resolution Wide-Swath SAR Imaging
Azimuth Phase Center Adaptation on Transmit for High-Resolution Wide-Swath SAR Imaging
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DOI：
10.1109/lgrs.2009.2025245
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发表时间：
2009-10-01
影响因子：
4.8
通讯作者：
Krieger, Gerhard
中科院分区：
文献类型：
--
作者：
Gebert, Nicolas;Krieger, Gerhard
具有多个接收通道的合成孔径雷达（SAR）系统允许高分辨率宽测绘带成像，从而克服常规单孔径SAR的基本限制。通过在方位角上使用多个孔径，针对每个发射脉冲接收附加样本。这允许减小的脉冲重复频率（PRF），从而实现更宽的扫描带。然而，一个非最佳的PRF是与一个非均匀的采样间隔在方位角，需要通过一个多通道重建算法进行补偿。对于与最佳PRF的强烈偏差，这种算法的逆特性可能导致性能下降。这可以通过创新的先进发射天线架构来克服，该架构允许相位中心的脉冲到脉冲移位。这样的天线使得能够将系统的相位中心位置自适应地调整到相应的PRF，从而确保在明显扩展的PRF范围上的恒定性能。特别是，与传统的多通道处理策略相结合，该技术代表了迈向完全有源多输入多输出（MIMO）SAR的下一步，并且在未来系统中具有巨大的潜力。
Synthetic aperture radar (SAR) systems with multiple receive channels allow for high-resolution wide-swath imaging thus overcoming a fundamental limitation of conventional single-aperture SAR. By using multiple apertures in azimuth, additional samples are received for each transmitted pulse. This allows for a reduced pulse repetition frequency (PRF) thereby enabling a wider swath. However, a nonoptimum PRF is associated with a nonuniform sample spacing in azimuth and needs to be compensated by a multichannel reconstruction algorithm. For strong deviations from the optimum PRF, the inverse character of such an algorithm might result in a degraded performance. This can be overcome by an innovative advanced transmit antenna architecture which allows for a pulse-to-pulse shift of the phase center. Such an antenna enables the adaptive adjustment of the system's phase center positions to the respective PRF, thereby ensuring constant performance over a clearly extended PRF range. In particular, in combination with conventional multichannel processing strategies, this technique represents the next step toward a fully active multiple-input multiple-output (MIMO) SAR and has a great potential for future systems.