Calibrating an optical FMCW backscattering measurement system

US7742892B2 · kind B2 · utility

Assignee

• LIOS TECHNOLOGY GMBH · DE

Inventors

• Martin Fromme · Cologne, DE
• Ulrich Glombitza · Bensberg, DE

Key dates

• Filing date: Sep 7, 2005
• Grant date: Jun 22, 2010
• Expiry date: May 19, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G01K11/32
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The object of the invention is to provide a method of calibrating an optical FMCW backscattering measurement system that improves the precision of the measurement. The problem is solved by a method comprising the steps of A. Converting said received sensor signal to a complex received electrical signal as a function of said modulation frequency fm, said complex received electrical signal being represented by a magnitude part and a phase angle part as a function of said modulation frequency fm; B. Performing a transformation of said received electrical signal to provide a backscattering signal as a function of location between said first and second ends of said sensor and beyond said second end; C. From said backscattering signal as a function of location determining characteristics of a curve representative of said backscattering signal beyond said second end; D. Correcting said magnitude part of said received electrical signal and said phase angle part of said received electrical signal in a predetermined dependence of said curve; and E. Repeating step B) on the basis of the corrected received electrical signal.