ACCURACY LIMITATIONS ON BRILLOUIN LIDAR MEASUREMENTS OF TEMPERATURE AND SOUND SPEED IN THE OCEAN

There are five mutually dependent variables relevant to Brillouin Lida r measurements of temperature and sound speed in the ocean; they are ( 1) the Brillouin shift, (2) the sound speed, (3) the index of refracti on, (4) the temperature, and (5) the salinity. We use three well-known relations to analyze rigorously the interdependence of these five var iables. Clearly, a Brillouin shift measurement does not provide a stan d-alone determination of temperature or sound speed; one more variable or one more relation must be known. The use of mean values of salinit y that have been obtained by an analysis of a large set of historical in situ data is considered for this additional relation. (C) 1997 Opti cal Society of America.