Phased Array Refractivity Estimation in Coastal Ducting Environment

Vertical refractive index gradients influence electro-magnetic signal ducting, greatly affecting system performance. Characterizing the refractive environment by parameter estimation has been demonstrated by incoherent systems measuring only amplitude fluctuation. Refractivity estimation by a fully coherent, amplitude and phase capable system had not been comprehensively examined prior to the coastalland-air-sea interactions mission. During this mission, coherent vertical array measurements alongside precision meteorological observations has produced results comparing equivalent coherent and incoherent systems and explored the feasibility of deploying phased array systems for refractivity estimation.