Patent ID: 7884937
Filing Date: 2011-02-08
Classification: G01N,G01S,Y02A

Abstract:
1. A method for measuring target gas concentrations in an atmosphere, comprising: emitting in the atmosphere a laser beam tuned to an infrared molecular absorption line of a target gas, the laser beam having a spectral bandwidth greater than a full width of the molecular absorption line of the target gas; receiving a reflected signal affected by gas absorption of the target gas; dividing and directing the received signal into a first optical path and a second optical path, the first optical path including a correlation gas cell filled with a predetermined concentration of the target gas, the second optical path including a reference cell filled with air or filled with a gas different than the target gas; detecting transmitted signals through the first optical path and the second optical path; calculating a target gas concentration by comparing a first signal transmitted through the first optical path to a second signal transmitted through the second optical path.