CDL- Subsea Inertial Navigation sensor, survey sensor for ROV - Fibre Optic Gyro, Inertial Navigation, Subsea Instrumentation, Pitch and Roll, underwater, engineering, dynamic, survey, Underwater Engineering, Positioning Equipment, ROV, AUV, oil, pipes, offshore, underwater acoustics, subsea acoustics, sonar,INS, subsea INS, subsea inertial navigation, sparce LBL, USBL, USBL smoothing, metrology, subsea metrology,Fiber optic Gyro