Classification of Australian Waterbodies across a Wide Range of Optical Water Types

Round 1

Reviewer 1 Report

This is a very well written paper that is based on a quite substantial body of work by the authors. The authors carried out a detailed model based analysis of combined hyperspectral reflectance spectra and experimental in situ water constituent measurements. Based on this study they were able to classify the reflectance data of inland and coastal water into generalized optical water types (OWTs) and compare to satellite multi-spectral results. The results of this work are relevant and could become key inputs to operational continental scale monitoring and baseline determination of water quality retrieval, algal bloom detection, estimation of primary production, refining the distributions of bio-geographic provinces and developing indices of marine biodiversity.  For the reasons above I strongly recommend publication of this paper. I have noted a couple of minor deficiencies/improvements which should be addressed before publication

• Define SIOP acronym at least once.
• Produce a histogram of the Euclidian distances. This would give readers a better quantitative feel of problem and its statistical behavior.
• Explain what fractile of the distribution was chosen as criterion for groupings by Tukey HSD
• Add units to the first column of Table 2 and 3
• On line 273 you say “most assigned” (You need to define precisely (numerically) most.)

Author Response

Please see the attachment 

Author Response File: Author Response.pdf

Reviewer 2 Report

The submitted research work aims to enhance the knowledge about the optical complexity of Australian coastal and continental waters. I found this paper very interesting where Several technical aspects were nicely implemented and explained sufficiently. Undoubtedly, authors invested huge amount of time and have made a great effort to produce this high-quality of research which is clearly structured and the language used is largely appropriate. Nevertheless, I found few gaps that need correction and improvements. As final decision, I see that this manuscript in its form and level deserves to be accepted for publication in MDPI-RS BUT after addressing below MINOR COMMENTS.

DETAILED COMMENTS PER SECTION:

TITLE & ABSTRACT:

• The title is adequate for the content of the paper.
• The abstract gives a good overview about the undertaken work. Authors mentioned clearly the aim and objectives of their work and included all the required info in the abstract.
• Line 15 in the abstract, the definition of the acronym (OWTs) is not clear, please write clearly the corresponding of each letter.

INTRODUCTION:

• Generally, the introduction is well written and very organised.
• Line 45, Correct the acronym for Secchi disk depth to be (SDz).

Materials and Methods

• Please improve the quality of Figure 1 and add the North arrow to the map.
• The last column in Table 2, name the column “sdev” not sd.
• Line 191, the authors wrote “To capture enough variability in continental water quality, a large temporal and spatial dataset is required”, How enough variability can be quantified with large temporal and spatial dataset!? Please try to find the compromise here and rephrase if necessary.

RESULTS:

• This section has a good structure and nice figures.
• Figure 4, please add the title for the x axis.
• Good findings have been reported in this section, good job.

CONCLUSIONS:

• Authors made a very good conclusion and very interesting recommendations.
• As final general comment, please make sure to define ALL the acronyms form their first appearance in the paper. Also, all the references MUST BE CHECKED and formatted as required by MDPI-RS, also make sure that all the references have DOI number unless it is not available.

Author Response

Please see attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper describes in a very clear way a comprehensive experimental study.

To my opinion, the paper can be published in the present form.

Author Response

please see attachment

Author Response File: Author Response.pdf