Abstract: Disclosed is a method and a system for determining a velocity of a relative movement between a system for determining the velocity and a fluidal medium. The method includes directing at least two light beams through at least a portion of the fluidal medium using the system such that a portion of light of each light beam is absorbed by the fluidal medium. Further, the method includes detecting first and second spectral intensity profiles of at least two light beams to detect the light absorption. The method also includes determining a difference profile associated with spectral intensity differences between a first and a second spectral intensity profile; and integrating an absolute value function of the difference profile to determine the velocity. The at least two light beams are directed such that the first and second spectral intensity profiles each have a different spectral position. The system has components that are arranged to allow operation of the above-described method.

Abstract: Disclosed is a method and a system for determining a velocity of a relative movement between a system for determining the velocity and a fluidal medium. The method includes directing at least two light beams through at least a portion of the fluidal medium using the system such that a portion of light of each light beam is absorbed by the fluidal medium. Further, the method includes detecting first and second spectral intensity profiles of at least two light beams to detect the light absorption. The method also includes determining a difference profile associated with spectral intensity differences between a first and a second spectral intensity profile; and integrating an absolute value function of the difference profile to determine the velocity. The at least two light beams are directed such that the first and second spectral intensity profiles each have a different spectral position. The system has components that are arranged to allow operation of the above-described method.