Improved method for the optical determination of temperature profiles

The vertical temperature profile in the lower atmosphere was determined at heights from 60 cm to 180 cm from estimates of optical refraction obtained from photographs of illuminated targets over the ice of Lake Mendota, Madison, Wisconsin, during the winter of 1968. The targets consist of several equally spaced fluorescent lamps with the long axis along a line slanted 45 ° to the ice. Two targets were placed 750 m and 1500 m from the camera. A simplified model relating lapse rate to the radius of curvature of a light ray is used for computation. Results show that the technique is more reliable for estimates of profile shape than for estimates of lapse rate values.