Measurement of Atmospheric Surface Pressure with a Satellite-Borne Laser
by S. Fred Singer
Presented at the Ocean Observing System for Climate Symposium in St. Raphael, France, October 1999.

A laser system operating in the molecular oxygen-A band (near 0.76 microns) can be used to measure surface pressure by determining absorptance inside and outside of the bands. An accuracy of 1 mbar may require averaging 30 pulses using a 10-m2 receiver. A systems analysis shows that internal noise is negligible and that background is not serious, even in daylight. As compared with the corresponding method using the Sun as a source, the laser method can be used at night, can discriminate cloud vs surface reflections, and may be able to determine altitude, pressure, and (by IR flux measurement) the temperature at selected points in the atmosphere. An early test in a manned orbiting satellite is proposed. If successful, the method will have important applications to the projected Earth Observing Program, to cloud studies, and to oceanography.