Guest editorial: recent advances in synthetic aperture sonar technology

Compared to traditional sidescan sonar, synthetic aperture sonar (SAS) or Interferometric synthetic aperture sonar (InSAS) systems can provide much higher resolution images across the whole swath. Due to the high resolution and fast mapping rate at a given speed, SAS/InSAS technology is gaining increasing interest within the field of underwater engineering. Navigation, autonomous underwater vehicles (AUVs), sonar technolog and electronics have achieved great progress in recent years. Thanks to these developments, the SAS/InSAS has also been pushed into a new stage. Firstly, the lightweight and compact SAS can be mounted on ever smaller, highly flexible platforms. Secondly, current algorithms are computationally more efficient. Thirdly, the SAS/InSAS images are further improved based on various methods. Last but not least, SAS/InSAS technology is preferred by underwater mapping users due to its high resolution. The current Special Issue is focused on research ideas, articles and experimental studies related to "Recent Advances in Synthetic Aperture Sonar Technology" for development, operating mode, algorithms and applications the various aspects of SAS/InSAS in applications.