RADIANCE-IRRADIANCE INVERSION ALGORITHM FOR ESTIMATING THE ABSORPTIONAND BACKSCATTERING COEFFICIENTS OF NATURAL-WATERS - HOMOGENEOUS WATERS

A full multiple-scattering algorithm for inverting upwelling radiance (L-u) or irradiance (E-u) and down-welling irradiance (E-d) profiles i n homogeneous natural waters to obtain the absorption (a) and backscat tering (b(b)) coefficients is described and tested with simulated data . An attractive feature of the algorithm is that it does not require p recise knowledge of the scattering phase function of the medium. For t he E-u-E-d algorithm, tests suggest that the error in the retrieved a should usually be less than or similar to 1%, and the error in b(b) le ss than or similar to 10-20%. The performance of the L-u-E-d algorithm is not as good because it is more sensitive to the scattering phase f unction employed in the inversions; however, the error in a is usually still small, i.e., less than or similar to 3%. When the algorithm is extended to accommodate the presence of a Lambertian-reflecting bottom , the retrievals of a are still excellent, even when the presence of t he bottom significantly influences the upwelling light field; however, the error in b(b) can be large. (C) 1997 Optical Society of America.