Abstract: Traditional high frequency (HF) finding system needs a large and plain area for antenna array, so it is difficult to find a suitable place for practical HF direction finding systems. To address this issue, an improved mutiple signal classification (MUSIC) algorithm is proposed for HF direction finding system with non-regular antenna array. This algorithm makes it possible to deploy HF direction finding system not only in plain area but also in the conditions of complex terrain, which makes it much easier to find a place to deploy HF direction finding system. On the basis of theoretical modeling and computer simulation, a prototype system of HF irregular array direction finding was developed and tested in the real environment. The experiment results showed that the improved MUSIC algorithm was available for direction finding in the condition of non-regular antenna array, and the corresponding HF direction finding systems can work well with complex terrain conditions.

Key words: shortwave, non-regular antenna array, improved multiple signal classification algorithm