多基地逆合成孔径声纳（ISAS）成像是指利用声纳组网对水下航行器、潜艇等水下运动目标进行高分辨成像，具有安全隐蔽性高，抗干扰能力强、作用范围广以及获取信息丰富等优势。目前水下目标成像存在高旁瓣、强多径、高噪声以及信息融合困难等问题，本项目将开展多基地ISAS波形设计和高精度成像研究，主要包括三个方面。首先，设计适用于水下目标ISAS成像系统的波形，实现距离旁瓣和距离单元间干扰抑制，建立基于正交频分复用（OFDM）波形的ISAS成像模型，为后续的参数估计和质量增强算法奠定模型和数据基础；其次，针对水下目标的运动特性以及复杂的水下声场环境，研究融合声速校正的优化聚焦方法，最后，结合多基地布站特点，设计多基地ISAS抗多径波形，研究多基地信息保持的成像质量增强，主要包括对聚焦、分辨率和多径抑制的性能提高。研究成果有望大幅提高水下目标成像性能，对我国反潜与海上作战能力的提高做出贡献。

Multistatic inverse synthetic aperture sonar (ISAS) imaging is defined as using sonar network to image underwater moving targets, such as underwater vehicles, submarines, etc. Multistatic ISAS systems have the advantages of high security, anti-interference, large detecting areas and rich information acquisition. At present, there are still some difficulties in ISAS imaging of underwater targets, including high sidelobes, strong Doppler, multipath interference and information fusion. The program will develop the research on multistatic ISAS waveform design and high-precision imaging methodologies. The main content of this program includes three aspects. Firstly, combining the orthogonal frequency division multiplexing signal characteristics, the waveform design methodology for ISAS imaging systems is proposed, which can effectively suppress range sidelobes and inter-range-cell interference. The establishment of the OFDM ISAS imaging model paves a way for the parameter estimation and image quality enhancement. Secondly, based on the motion characteristics of underwater targets and complex underwater acoustic field, the autofocus method is developed. The combination of motion parameter estimation and sound velocity compensation for autofocusing algorithm can effectively improve the imaging quality. Finally, we discuss the image quality enhancement method by exploiting multistatic information, where focusing, resolution and multipath interference is mainly concentrated in the content. The research achievements may largely improve the imaging performance of the underwater targets, and make a contribution to the anti-submarine and combat capability of our country.