Feature of development of the APS for very long range AUV

In this report features of the development of the integrated acoustical positioning system (APS) for the AUV, which must work in deep sea near the bottom, are discussed. This navigation system must determine the AUV coordinates on board the vehicle and on board of the ship carrier (SC). In contrast with the traditional APS, the range of which is limited by the nearbottom refraction, the suggested APS has the nearsurface beacon-retranslator, which increases the zone of insonification to the limiting value R₁≈(7÷8)H, (H-sea depth), and two ultra-short baseline (USBL) APS, installed on the AUV and SC. For decreasing error of coordinate determination with the condition of multipath propagation the joint processing of range and phase information using invariant velocity is suggested