Amateur Optical Communication Record

The current amateur radio record for long distance terrestrial optical communication is ~173 mi (278.4km), set in 2008. The record-holders maintain an extensive website at modulatedlight.org [1]. Some notable characteristics of their link include: Fresnel lens transmitter and receivers, a custom low-bandwidth, low-noise receiver optimized for long distance, red LED transmitters, and simple tripod alignment. Their path crossed the Great Salt Lake Desert, taking advantage of optimal atmospheric conditions. The group used Google Earth to simulate view from each site to find landmarks, but were surprised by how different things looked with haze. Their successful link was able to transmit VHF ham radio communications.

The Stanford SSI OpComms group aims to surpass this record, using a terrestrial transmitter and receiver currently under development.