RAMSES is an acoustic synthetic baseline positioning system with self-contained computing, for simple real-time sparse array subsea navigation. Tightly coupled with iXBlue inertial navigation system (INS), it delivers extreme precision and robustness in challenging acoustic operational environment. Available in MF and LF versions (medium frequency for most applications and low frequency for ultra-long range applications), RAMSES is part of iXBlue inertial-acoustic solutions for underwater positioning and navigation. The solution combines RAMSES system with GAPS and POSIDONIA iXBlue ultra-short baseline (USBL) positioning systems.