In array signal processing, 2-D spatial-spectrum estimation is required to determine DOA of multiple signals. The circular array of sensors is found to possess several nice properties for DOA estimation of wide-band s...In array signal processing, 2-D spatial-spectrum estimation is required to determine DOA of multiple signals. The circular array of sensors is found to possess several nice properties for DOA estimation of wide-band sources. C. U. Padmini, et al.(1994) had suggested that the frequency-direction ambiguity in azimuth estimation of wide-baud signals received by a uniform linear array (ULA) can be avoided by using a circular array, even without the use of any delay elements. In 2-D spatial-spectrum estimation for wide-band signals, the authors find that it is impossible to avoid the ambiguity in source frequency-elevation angle pairs using a circular array. In this paper, interpolated circular arrays are used to perform 2-D spatial-spectrum estimation for wide-band sources. In the estimation, a large aperture circular array (Υ】λmin/2) is found to possess superior resolution capability and robustness.展开更多
无人机协同目标感知技术是有人机无人机混合运行的重要安全保障.针对复杂空域环境下的感知可靠性问题,分析大中型无人机的复杂融合空域运行场景,并确定无人机协同目标感知的精准性、高实时性、抗干扰性和低载荷性等需求,提出一种四单元...无人机协同目标感知技术是有人机无人机混合运行的重要安全保障.针对复杂空域环境下的感知可靠性问题,分析大中型无人机的复杂融合空域运行场景,并确定无人机协同目标感知的精准性、高实时性、抗干扰性和低载荷性等需求,提出一种四单元阵列天线和数字化射频体制的无人机协同目标感知系统架构;同时,结合空管雷达信号特性和天线体制,设计方位感知算法,通过修正协方差矩阵、信号子空间加权和噪声子空间加权等方法,设计基于多信号分类(multiple signal classification,MUSIC)的空间谱估计算法,并提出基于子空间分解的幅相误差在线估计算法;最后,开展算法仿真试验和实际空域环境飞行试验.研究结果表明:相比传统MUSIC算法,优化算法的方位感知高分辨性能提升23.3%,并改善了无人机协同目标方位感知的高实时性、抗干扰性和低载荷性.展开更多
In array signal processing,the existing methods for DOA estimation of wide-band signals are only related to the azimuth estimation when the number or sensors is known.It is shown that a circular array possesses severa...In array signal processing,the existing methods for DOA estimation of wide-band signals are only related to the azimuth estimation when the number or sensors is known.It is shown that a circular array possesses several nice properties.2-D spatial-spectrum estimation for wide-band sources is performed by using a circular array of sensors with sample delay lines.Further,the Choi’ s approach is extended,which was suggested to estimate DOA of narrow-band signals when the number of sensor was unknown,to wide-band signal processing.The extended approach is shown to be quite adequate for wide-band signal subspace spatial-spectrum estimation (BASS-LE),and a large aperture (r】λvin/2) circular array is found to possess superior resolution capability and robustness.展开更多
针对现有协同表示算法应用在高光谱遥感图像分类过程中出现的较差分类精度的问题,提出了一种基于加权判别性协同表示的分类算法。提出的算法对高光谱图像进行基于空间邻域的平滑化处理以消除图像中的噪声和异常光谱。通过考虑训练样本...针对现有协同表示算法应用在高光谱遥感图像分类过程中出现的较差分类精度的问题,提出了一种基于加权判别性协同表示的分类算法。提出的算法对高光谱图像进行基于空间邻域的平滑化处理以消除图像中的噪声和异常光谱。通过考虑训练样本和测试样本的相关性提出基于相关性的加权正则项;通过考虑不同类别训练样本重构给定测试样本的误差进一步提出了基于最小重构误差的正则项。在Indian Pines和University of Pavia两种真实数据集上的实验结果表明,所提出的算法相比其他典型的基于协同表示的分类算法具有更高的分类精度,分别能获得98.2%和95.70%的总体精度。实验证明,所提出的分类器算法有效改善了现有基于协同表示的高光谱图像分类方法的低精度问题。展开更多
针对多重信号分类(multiple signal classification, MUSIC)算法在低阵元数目、低信噪比和小节拍数等非理想条件下,对入射间隔较小的信号波达方向(direction of arrival,DOA)估计有效性的问题,提出了改进的基于酉重构子空间的MUSIC算法...针对多重信号分类(multiple signal classification, MUSIC)算法在低阵元数目、低信噪比和小节拍数等非理想条件下,对入射间隔较小的信号波达方向(direction of arrival,DOA)估计有效性的问题,提出了改进的基于酉重构子空间的MUSIC算法。该算法首先利用酉变换将均匀线阵接收数据实数化,然后根据子空间特征向量的大小,重新构造子空间和校正矩阵得到新的空间谱函数,最后与信号子空间投影算法联合,实现DOA估计。仿真结果表明,与传统MUSIC算法和SSP算法相比,所提算法在低阵元数目、低信噪比和小节拍条件下具有更好的分辨率。展开更多
随着信息对抗的发展,敌我双方都开始使用大量雷达和干扰设备,电磁干扰环境日渐复杂,干扰抑制已成为亟须解决的难题。通常使用干扰对消技术与空间自适应干扰抑制技术来进行干扰抑制。针对空间自适应干扰中需要已知信号源波达方向(Directi...随着信息对抗的发展,敌我双方都开始使用大量雷达和干扰设备,电磁干扰环境日渐复杂,干扰抑制已成为亟须解决的难题。通常使用干扰对消技术与空间自适应干扰抑制技术来进行干扰抑制。针对空间自适应干扰中需要已知信号源波达方向(Direction Of Arrival,DOA)的问题,提出了利用空间谱估计测向技术进行自适应干扰抑制前的DOA估计。该做法不会额外增加系统的通道和硬件资源,且能同时估计多个信源的方向,测向精度高,稳定性好。该系统可以在无须辅助通道和其他干扰源先验信息的条件下,有效消除接收信号中的多个干扰分量,恢复原始通信信号。展开更多
文摘In array signal processing, 2-D spatial-spectrum estimation is required to determine DOA of multiple signals. The circular array of sensors is found to possess several nice properties for DOA estimation of wide-band sources. C. U. Padmini, et al.(1994) had suggested that the frequency-direction ambiguity in azimuth estimation of wide-baud signals received by a uniform linear array (ULA) can be avoided by using a circular array, even without the use of any delay elements. In 2-D spatial-spectrum estimation for wide-band signals, the authors find that it is impossible to avoid the ambiguity in source frequency-elevation angle pairs using a circular array. In this paper, interpolated circular arrays are used to perform 2-D spatial-spectrum estimation for wide-band sources. In the estimation, a large aperture circular array (Υ】λmin/2) is found to possess superior resolution capability and robustness.
文摘无人机协同目标感知技术是有人机无人机混合运行的重要安全保障.针对复杂空域环境下的感知可靠性问题,分析大中型无人机的复杂融合空域运行场景,并确定无人机协同目标感知的精准性、高实时性、抗干扰性和低载荷性等需求,提出一种四单元阵列天线和数字化射频体制的无人机协同目标感知系统架构;同时,结合空管雷达信号特性和天线体制,设计方位感知算法,通过修正协方差矩阵、信号子空间加权和噪声子空间加权等方法,设计基于多信号分类(multiple signal classification,MUSIC)的空间谱估计算法,并提出基于子空间分解的幅相误差在线估计算法;最后,开展算法仿真试验和实际空域环境飞行试验.研究结果表明:相比传统MUSIC算法,优化算法的方位感知高分辨性能提升23.3%,并改善了无人机协同目标方位感知的高实时性、抗干扰性和低载荷性.
文摘In array signal processing,the existing methods for DOA estimation of wide-band signals are only related to the azimuth estimation when the number or sensors is known.It is shown that a circular array possesses several nice properties.2-D spatial-spectrum estimation for wide-band sources is performed by using a circular array of sensors with sample delay lines.Further,the Choi’ s approach is extended,which was suggested to estimate DOA of narrow-band signals when the number of sensor was unknown,to wide-band signal processing.The extended approach is shown to be quite adequate for wide-band signal subspace spatial-spectrum estimation (BASS-LE),and a large aperture (r】λvin/2) circular array is found to possess superior resolution capability and robustness.
文摘针对现有协同表示算法应用在高光谱遥感图像分类过程中出现的较差分类精度的问题,提出了一种基于加权判别性协同表示的分类算法。提出的算法对高光谱图像进行基于空间邻域的平滑化处理以消除图像中的噪声和异常光谱。通过考虑训练样本和测试样本的相关性提出基于相关性的加权正则项;通过考虑不同类别训练样本重构给定测试样本的误差进一步提出了基于最小重构误差的正则项。在Indian Pines和University of Pavia两种真实数据集上的实验结果表明,所提出的算法相比其他典型的基于协同表示的分类算法具有更高的分类精度,分别能获得98.2%和95.70%的总体精度。实验证明,所提出的分类器算法有效改善了现有基于协同表示的高光谱图像分类方法的低精度问题。
文摘针对多重信号分类(multiple signal classification, MUSIC)算法在低阵元数目、低信噪比和小节拍数等非理想条件下,对入射间隔较小的信号波达方向(direction of arrival,DOA)估计有效性的问题,提出了改进的基于酉重构子空间的MUSIC算法。该算法首先利用酉变换将均匀线阵接收数据实数化,然后根据子空间特征向量的大小,重新构造子空间和校正矩阵得到新的空间谱函数,最后与信号子空间投影算法联合,实现DOA估计。仿真结果表明,与传统MUSIC算法和SSP算法相比,所提算法在低阵元数目、低信噪比和小节拍条件下具有更好的分辨率。
文摘随着信息对抗的发展,敌我双方都开始使用大量雷达和干扰设备,电磁干扰环境日渐复杂,干扰抑制已成为亟须解决的难题。通常使用干扰对消技术与空间自适应干扰抑制技术来进行干扰抑制。针对空间自适应干扰中需要已知信号源波达方向(Direction Of Arrival,DOA)的问题,提出了利用空间谱估计测向技术进行自适应干扰抑制前的DOA估计。该做法不会额外增加系统的通道和硬件资源,且能同时估计多个信源的方向,测向精度高,稳定性好。该系统可以在无须辅助通道和其他干扰源先验信息的条件下,有效消除接收信号中的多个干扰分量,恢复原始通信信号。