Measurement of atmospheric surface pressure with a satellite-borne laser

A laser system operating in the oxygen A band (near 0.76 mu) can be used to measure surface pressure by determining absorptance inside and outside of the bands. An accuracy of 10 mbar may require thirty pulses, using a 1-m(2) 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, the laser method can be used at night, can discriminate cloud vs surface reflections, and may be able to determine altitude, pressure, and 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 Global Atmospheric Research Program, to cloud studies, and to oceanography.