Development and testing of an acoustic positioning system - description and signal processing

This work presents an USBL Acoustic Positioning System developed for an underwater vehicle. The position, estimation is based on time-of-arrival (TOA) estimation of acoustic signals traded between a transponder and a transducer array placed on the vehicle. Modulated Barker-coded signals are used to achieve low ambiguity. Real-time DSP is implemented in a Programmable Logic Device. The TOA estimator uses a time-domain matched filter with quantized coefficients. The signal design is based on the characteristics of the employed acoustic transducers and system requirements. Numerical simulations and FPGA realization tests have shown the viability of implementing the proposed TOA estimator.