By 1986, FRF scientists and technicians designed and built a novel wave sensor. A fixed, precisely-surveyed array of pressure gauges working in sync forming a wave antennae with a directional resolution well beyond that of buoys; details can be found in [1]. From 1986 - 1990, the array consisted of 10 elements parallel to the shore, referred to as the "linear array". The linear array resolved directional spectra but with 180 degree ambiguity. Although most of the wave energy propagates towards the coast, there is some fraction of reflected wave energy (not resolved).Please see the FRF data paper, FRF website, and FRF data portal for more information.[1] Long, C. E. and Oltman-Shay, J. M. (1991)