2.4.4 3 Dimensional Acoustical Positioning System (3DAPS)

The 3DAPS system is planned to allow Ranger NBV to calculate its position and attitude in the neutral buoyancy environment. The position and attitude are calculated from an array of thirty two ranges which are collected by measuring time of flight of sound pulses traveling through water from acoustical emitters at known locations in the environment surrounding the vehicle to acoustical receivers at known locations Ranger NBV. Only six ranges are needed to fully determine position and attitude, so the extra ranges serve to increase accuracy and provide redundancy in the event that one or more of the emitter signals are blocked. The range data is to be collected by the ESU 6811 microprocessor through a SSL produced acoustic filter board. The estimated attitude is then calculated, and returned to the main processor via a RS422 serial communications line.
The 3DAPS system is still under development, and its data is not yet available for vehicle state estimation.