This distance measurement by radar a continuous wave modulated in frequency, apparatus for implementing the process and a precise determination of the liquid level in a reservoir

摘要

The known part of the apparatus according to the invention is constituted by a radar a continuous wave f modulated linearly saw teeth of the frequency excursion δf during the time t and of the central frequency f. according to the invention, said radar further comprises a phase loop for the stabilization of df and f with the precision of a quartz, on the other hand, a device for the precise measurement of the time t, the frequency f of the beat signal fb between wave emise and wave recue after reflection on an object and the phase ph of fb the start of the ramp of the saw tooth. The process according to the invention consists in calculating then with the aid of a microprocessor 10 a first value of the distance d between the radar and determining the object as a function of df, f and t and then a second value of d to be more precise from, ph and the value f, f at the start of the ramp. / p & & p & a measurement of the height of a liquid in a reservoir.