Modified gain extended Kalman filter with application to angles only underwater passive target tracking

The modified gain extended Kalman filter (MGEKF) developed by Song and Speyer (1985) was proven to be a suitable algorithm for angles only passive target tracking applications in the atmosphere. Recently this algorithm has been extended with approximately modified gains, which are numerically stable and accurate. In this paper, this improved MGEKF algorithm is explored for underwater applications with some modifications. Underwater noise measurements are very high, the turning rate of the platforms is low and the speed of the platforms is also low when compared with missiles in the air. These characteristics of the platforms are studied in detail and the algorithm is modified suitably for tracking applications underwater. Monte-Carlo simulated results for one typical scenario are presented for the purpose of explanation. .From the results it is observed that this algorithm is suitable for underwater passive target tracking using angles only measurements.