Laser remote sensing of atmospheric temperature by observing resonant absorption of oxygen

Measurement of atmospheric temperature through the monitoring of laser energy absorption at the center of an O(2) resonant absorption line near 770 nm has been demonstrated using a dual frequency system. The average temperature of a 1-km path can be determined to better than 1.0 degrees C with a noise level of 0.3 degrees C. An iterative algebraic expression for determining temperature from the measured absorption was developed and shown to be applicable in the troposphere. The effects of pressure and humidity on temperature determination are clear from the algorithm and found to be small near the earth's surface.