Abstract– Most previous studies in estimation of the target position and velocity through Bearing
Only Measurements (BOM) consider targets with constant velocity moving along a straight line.
In this paper, state and measurement equations are presented for moving targets with constant
acceleration by using the previously presented state vector in the Extended Modified Polar
Coordinates (EMPC) system. In the BOM systems, by increasing the distance between target and
observer (Own ship) the estimation accuracy of the target kinematic parameters degrades
noticeably. In order to solve this problem, here the idea of hybrid data measurements is presented.
In this approach both low rate range information, from active sensor, and high rate BOM are
exploited. The improvement in the performance of the hybrid system compared to BOM system is
represented through computer simulations.