Measurement of average atmospheric temperature using a CO_2 laser radar

A single-ended CO2 lidar system has been used to measure the average temperature over a path between the lidar and the foothills located 5 km away. The CO2 lidar was used to measure the ratio of transmission of the P(38) to the P(20) lines in the 10-μm band of CO2. This ratio of transmission is directly related to temperature. Good correlation was obtained between the lidar-measured temperature and the thermometer-measured values.