Long range audio laser communication link in a maritime environment

The Defence Science & Technology Organisation (DSTO), in collaboration with the US Naval Research Laboratory (NRL), has performed long distance experiments on analogue modulated free space optical links across Chesapeake Bay, Maryland. In the present work, pulse frequency modulation was used to transmit audio signals over a distance of 32 km (folded path across the Bay). Still images were transmitted using slow scan television (SSTV) techniques, and a novel technique to decrease the transmission time of SSTV images is presented.