Mesocavity specular integrator refractometer

Claim 1

A mesocavity specular integrating refractometer for measuring atmospheric refractivity comprising in combination: a single-frequency coherent radio wave interferometer of obtuse triangular configuration; a microwave generator for generating a frequency stable continuous microwave signal coupled to a directional beam emitter which is positioned at the obtuse apex of the triangular configuration and oriented to aim a direct microwave beam signal toward the most acute apex of the triangular configuration; a passive plane reflector positioned at the most acute apex of said triangular configuration and oriented to reflect and critically aim said direct microwave beam signal toward the less acute angle of said triangular configuration; a coherent radio receiver means consisting of a superheterodyne phase-lock loop receiver locked in phase with the direct microwave beam signal and a superheterodyne receiver comprising a slave receiver coupled to the superheterodyne phase-lock receiver; a first parabolic antenna coupled to the input of the phase-lock loop receiver and oriented in a direction most favorably to the incidental rearward radiation of the direct microwave beam signal by said emitter and least favorably directional to the critically aimed reflected microwave signal whereby said direct microwave signal is applied to the input of the said phase-lock receiver; a second parabolic antenna coupled to the input of said slave receiver and oriented in a direction most favorably directional to critically aimed reflected microwave signal and least favorably to said incidental rearward radiation whereby said reflected microwave signal is applied to the input of said slave receiver; said superheterodyne phase-lock receiver locked in phase to said direct microwave signal from said emitter by phase-lock loop circuit means therein and supplying coherent locally generated oscillatory energy to said slave receiver for microwave signal to intermediate frequency conversion, detection and phase reference; a phase comparator coupled to the output of said slave receiver providing a resultant difference voltage proportional to the phase angle between intermediate frequency voltages in said slave receiver derived from the direct and reflected microwave signals, said difference voltage representing variation of the phase velocity of said reflecteD signal due to changes in refractive index in the two-way space path intermediate the emitter and plane reflector; and, recording means coupled to the output of the phase comparator for recording the difference voltage variations.