Underwater Wireless Sensor Networks: Estimation of Acoustic Channel in Shallow Water

Round 1

Reviewer 1 Report

The paper seems good in general. English editing is needed. I wished to see a comparison to some other existing work to evaluate the proposed method from different perspectives.

Author Response

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Reviewer 2 Report

The article is about underwater wireless sensor networks. It is an interesting topic, and the issue itself is not trivial.

The authors conduct the argument in a transparent manner, understandable to the reader.

However, the article would require an extension of the discussion of the results obtained. Merely presenting the results is not enough.

In addition, the magazine has the title "Applied ..." which requires, in my opinion, in addition to present the results of the simulation experiment, or at least a reference to the experimental results of other authors.

Authors should also pay attention to the formatting of the text, e.g. no period at the end of the sentence (16), no space between the values and the comma (75), or no space between the value and the name (78), etc.

Author Response

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Reviewer 3 Report

There a number of terms used in the paper that are not properly defined. For instance, in Table 1 there are terms like  pl/p cl/c cl (m/s) that are not defined or explained. 

Fundamentally, I find the paper confusing. The paper states 

"The effect of multipath has a stronger impact on capacity 434 than environmental effects such as changes in temperature or salinity "

This means that the multi-path effects are the dominant effect. The paper also states

"The receiver node gets 503 data from both the direct path in less time and the reflection paths formed by the surface and bottom 504 at longer time."

This makes sense, the multi-path reflections will combine out of phase with the direct patch signal and and this interference/noise will result in a reduction in the channel capacity. In this view, multipath reflections are bad. A system with reduced amplitude multi-path reflections will suffer less degradation/interference.

The text states conclusions that seem contrary to this, such as 

"So, another conclusion of this paper, thus related to the effects of the bottom materials, is that the 507 acoustic communication capacity available is higher if the bottom material is less porous compared to 508 the case of a more porous material."

My interpretation is this is saying that communication capacity is higher when a bottom material is less porous (a more efficient reflector - yielding a stronger multi-path reflection.) This is counter to the idea that weaker multi-path reflections will produce less interference.

I'm not sure if I am just misreading what the paper is trying to say or if the paper is inconsistent. At the least, given that multipath is stated to be the dominant effect, the sections explaining how the multipath simulations include the direct path and any subsequent conclusions need to be much clearer.

 

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Edits address the concerns.