DISTANCE MEASURING APPARATUS Russian patent published in 2004 - IPC

FIELD: measuring processes and equipment, namely distance measuring devices operating with use of radar systems at periodic frequency modulation of sounding signal.

SUBSTANCE: method comprises steps of generating and sounding signal and emitting it while subjecting said signal to periodic frequency modulation, at first in maximum range of frequency modulation; receiving echo-signal and mixing it with part of separated sounding signal for forming difference frequency signal; calculating (with use of difference frequency signal formed during half-period of modulation) spectrum, its central frequency, distance until sounded surface and number of length intervals included in measured distance value and corresponding to integer number of half-periods of difference frequency signal; reducing initial range of frequency modulation and changing its initial frequency until achieving maximum of spectrum for its central frequency; calculating spectrum maximum according to difference frequency signal formed during time interval multiple to several modulation periods; measuring central frequency of spectrum after achieving spectrum maximum and calculating distance. According to invention number of analysis periods of frequency modulation realized with use of triangle symmetry law is selected depending upon desired accuracy degree of measuring distance. Minimum interval of distance corresponds to one half-period of difference frequency signal.

EFFECT: enhanced accuracy for measuring distance due to increased duration of processing sampled signal of difference frequency.

4 cl, 3 dwg