Multi-Band Polarization Imaging in a Harsh Sea Fog Environment

Round 1

Reviewer 1 Report

Comments for author File: Comments.pdf

Author Response

On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manu.Please see attachment for related responses. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Review to applsci-2067883

(Multi-band polarization imaging in harsh sea fog environment)

 

The paper describes the details of imaging under sea fog conditions. The authors observe experimentally and describe influence on imaging of wavelength (three visible wavelengths of 450, 530 and 670 nm are considered), light polarization state, fog density and solar position. The paper can be useful for specialists dealing with outdoor imaging in fog or haze environment. I would like to recommend this paper for publishing, after the authors have addressed the following questions and comments:

 

1.     The authors observe image quality improvement with increased wavelength. This is no surprising given the scattering effects intensity being inversely proportional to the wavelength and so the transmission of longer wavelengths is less sensitive to scattering by atmospheric aerosols. Even more impressive examples of contrast improvement can be achieved at further increasing the wavelength by means of using near infrared imagers like one presented here https://www.laserfocusworld.com/detectors-imaging/article/16556355/photonics-products-imaging-for-surveillance-and-security-swir-cameras-cut-through-haze-for-surveillance-and-securityThe authors should refer to examples of hyperspectral imaging and comment on their decision to use visual range imager instead

2.     The authors should provide a comprehensive explanation of why the contrast is improved for polarized images and for images taken for longer wavelengths.

3.     The measurement procedure for optical thickness should be revealed

4.     It is not clear why the authors explain the contrast change (fig 13) through the change of solar altitude, as the latter changes monotonously and the former does not. The authors give average value for optical thickness as 0.36, was it controlled hourly throughout the whole experiment, what was the deviation? Is it possible that the change in fog density affected the contrast? What is the error of contrast measurement and is it correct to say that at 13:00 the contrast of polarization image is higher than that of the intensity image 

 

Minor corrections:

·  Line 19: term “phase delayer” should be replaced with “phase retarder”, which is more conventional

·  Line 23: solar altitude Angle(1) and multiband(2) – 1) capital letter is not needed and 2) noun is missing

·   Eq. 6: The abbreviation LCVR is first used at p. 3, but only explained at p. 4

·     Line 204: Heading is misprinted

·      Line 235: size  value

·      Table 2: resolution data are misprinted

·       Lines 256-262: repeating sentences

·     Lines 280-283: The description before figs. 6-8 should be optimized, as it may be confusing. One should point out clearly what stands for intensity images, what the difference is between b-d and keep it consistent throughout the following text.

·     Contrast data in figs. 7-8 seems mixed up comparing to fig. 9 and the text

·  I suppose that Tables 3 and 4-6 will be more comprehensive if presented as plots

·      Spacing between text, tables and figurescaptures should be improved

Comments for author File: Comments.pdf

Author Response

On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manu.Please see attachment for related responses.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The revised manuscript fails to address most of the reviewer critiques. Reviewer 1 requested calibration of the SALSA camera, separation of the target into different material classes (glass vs. asphalt/tar for instance), while both reviewers requested explanation for contrast variation with time-of-day. None of these critiques were adequately addressed in the revision. While two of the suggested references supporting separation of the target into different materials were cited, the concept was not integrated into the manuscript at all--the abstract of one reference was simply copied into the Introduction. While this is promising work, there are already numerous papers on this topic, with better results, so in my opinion this manuscript must be more consistent and insightful to contribute significantly to the field.

Author Response

Thank you for offering us an opportunity to improve the quality of our submitted manuscript.We appreciated very much your constructive and insightful comments.Please see the attachment for the specific response.

Author Response File: Author Response.docx

Reviewer 2 Report

I can see that the authors have made an effort to take into account all my comments. However, my concerns about Fig. 15 (Fig.13 in version 1) have not been addressed:

The authors give average value for optical thickness as 0.36, was it controlled hourly throughout the whole experiment, what was the deviation? Is it possible that the change in fog density affected the contrast? What is the error of contrast measurement and is it correct to say that at 13:00 the contrast of polarization image is higher than that of the intensity image

As it follows from Fig. 11, the optical depth does change throughout the day. However, for Fig. 15 the authors seem to ignore this effect. In the revised version of the manuscript, they haven’t provided any data on optical depth variation during the measurements. The question about the error of contrast measurement is not answered too. And, comparing Figs. 13 in old and revised versions, one can see data manipulation. If the authors cannot address such concerns, the figure should better be excluded from the manuscript.

Author Response

Thank you for offering us an opportunity to improve the quality of our submitted manuscript.We appreciated very much the reviewr'sconstructive and insightful comments.The specific reply is as follows.

After discussion, we decided to adopt your comments and delete (3) Solar altitude angle polarization imaging experiment.Please see the manuscript for the revised content.

 

Round 3

Reviewer 1 Report

Like to see effects of solar angle and material class in next paper