The standard remote sensing algorithms for chlorophyll a concentration and other biophysical parameters, mainly developed for relatively clear oceanic waters (Ccase 1) don't give sufficient accuracy in turbid coastal and inland waters (Case 2). The complicated optical properties of such waters are also impacted by seasonal changes in the dominant constituents of each class of substances what requires algorithms that account for these local and seasonal variations.

The dissertation contains the results of investigations into the upward light field conducted over a period of several years in the southern Baltic. The objective was to find relationships between certain remote sensing functions of the upward radiance and a number biophysical parameters of the marine environment , included chlorophyll a concentration as an index of phytoplankton concentration.. To achieve this objective, extensive field experiments for establishing the relevant statistical correlations, as well as a search for appropriate theoretical relations were carried out. These were intended to link the remote sensing functions indirectly to the environmental parameters through their relationships with the inherent optical properties of seawater. These correlations and relations were found and, as a final result, several local in-water remote sensing algorithms were worked out. These allow the principal water components in the Baltic to be estimated quantitatively from the values of upward radiance determined in the relevant spectral channels. The function measured is remote sensing reflectance under water surface at a few spectral bands, and the parameters found from the algorithms are as follows: concentration of surface chlorophyll, concentration of total suspensions and absorption of light at 400 nm by yellow substances.

On the basis of thoroughly reviewed current knowledge, the author has developed the most important aspects of the methods for building up the broad data base, necessary in this particular research. One of the innovative aspects of this dissertation is the methodology for the direct measurements of the upward radiance just below the sea surface, as an alternative to earlier indirect measurements which weren't effective in the waters with high absorption. The set of experimental data, gathered in 5 years of measurements, is clearly described and the end, the algorithms are given in detailed form.

The particular formulas of the algorithms are important and useful, but the general recipe for constructing them is even more important. This is also given. The usefulness of some types of formulas and uselessness of the others are discussed; the spectral bands most suitable under Baltic conditions are pointed out.

The conclusions are of some importance, too. The principal positive one confirms the present-day possibility of remote quantitative determination of concentration of chlorophyll a, suspensions and yellow substance in the surface layer of the Baltic. Another important conclusion, this time a negative one, precludes the practical possibility of remote detection of chlorophyll content with the aid of natural fluorescence, at least for the present.

The thesis is right up to date and contributes some new suggestions regarding the problem of local remote sensing. It is especially important for the Baltic region, where satellite methods are just being introduced for water quality control.