The Impact and Correction of Sensitive Environmental Factors on Spectral Reflectance Measured In Situ

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript describes experimental results with their own innovative facility called MHSRS2F to investigate the impact of five sensitive environmental factors on measured reflectance spectra. On this basis, the authors discussed the uncertainty and sensitivity caused by illumination and view geometry. Furthermore, the authors propose a new correction method for measured reflectance spectra. This work provides new insights and perspectives on the impact of illumination and view geometry on the spectral reflectance of rocks. The authors comprehensively quantify the uncertainty caused by illumination and view geometry, and try to proposes an effective spectral reflectance correction method for illumination and view geometry. From my point of view, this manuscript contains above important facts which would provide useful information and hence lead to a further understanding of this theme. 

The specific problems and related suggestions or opinions in this paper are as follows:

1）Table2: There is no detailed explanation on the setting of observation height and the design of the variation range in the experiment.

2）Line 269 - 274: The innovation of this work in exploring sensitivity is to use the reflectance collected by MHSRS²F to replace the results of measurement models. However, the specific experimental plan and how the experimental data used for research was obtained is still need to be described in more detail. I believe you need to supplement this section.

3）Section 3.3: panel correction factor in formula (8) and “a correction factor can be defined as Lp_before/Lp_after” in Line 324. These two correction factors seem to have different meanings, and you need to explain them clearly in the manuscript.

4）Formula(5): σ_{geometry_total}seems to have the same meaning as σ_geometry in formula (2), I think it should be changed to the same?

 

5) Table 3: Is combined standard uncertainty (last row) the same as the one defined by formula (5)? Need to explain clearly.

6) Line 214, 654, 671, 672, “MHSRS2F” ? Please check the superscript.

Comments on the Quality of English Language

Line 246 - 247: About the sentence, "Since … heterogeneity." Check the grammatical correctness.

Line 384: The sentence "The uncertainty refer to …" needs to be checked grammatically.(refers to??)

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper built a simulation device for hyperspectral remote sensing to evaluate the influencing factors of I&VG. The smaller the surface heterogeneity, the higher the uncertainty brought by the observation height. At the same time, the correction effects of different observation angles were evaluated.

 

 

 

The paper has conducted a large number of experiments and the conclusions are relatively reliable. But there are a few questions:

 

 

 

1.     Is there a deviation between the simulation device and the real scene situation, and if this deviation is evaluated?

 

2.     Can only doing rock samples explain all the issues? Have you analyzed artificial targets and other ground objects of different materials?

 

3.     How to analyze the correction ability? How was the comparative experiment designed?

 

4.     There are many formatting errors in the paper, and more checks are needed.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This research provides insights into the challenges of in site measurements and the influence of environmental factors, particularly I&VG. It offers a correction model that partially addresses these challenges, highlighting the complexities of accurate earth observation and the need for continuous refinement in measurement techniques. On the whole, the whole article has some mistakes and places worthy of revision. In addition, the language needs to be improved.

 Line 53-55:There's inconsistency in the terminology.  Choose between "Intensity of Illumination" (capitalized) and "illumination" (lowercase) based on context.

 Line 85-95:Some repetition around the challenges posed by I&VG.  Consider summarizing the main challenges more succinctly.

 Line 113: Title number error. 

Line 117-118:Grammatical Correction: Change "MHSRS2F (Figure 1) consist of" to "MHSRS2F (Figure 1) consists of".

 Line 127-128:Reformat the range of angles for clearer presentation, e.g., "The solar and view azimuth angles can be adjusted from 0° to 360°.  Solar zenith angles range from 15° to 60°, while view zenith angles span from 0° to 90°."

 Line 137-139:Instead of listing all rock types followed by their properties, consider breaking the information into two sentences: "The collected rock samples encompass a variety of types, including common sulfides, halides, oxides, carbonates, and silicates, as illustrated in Figure 3.  These samples exhibit diverse properties such as different colors, roughness, crystal structures, grain sizes, and gloss levels." 

Line 141:Grammatical Correction: Change "impact of environment conditions" to "impact of environmental conditions."

 Line 353:Grammatical Consistency: Change "a single I&VG parameters" to "single I&VG parameters."

 Line 497:Ensure that grammatical constructs are consistent.  "Finding" should be pluralized to maintain grammatical consistency.

 Figure 6: Figure 6 is very unclear, it is recommended to export a higher resolution graph, in addition, the text should be appropriately larger.

 Figures 9 to 13: The text in the figure is too small to read clearly. Please enlarge the text in the image appropriately.

Comments on the Quality of English Language      

The English of this paper is poor and difficult to be understood by readers.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Overall, the authors have presented a detailed study of the uncertainty and sensitivity of various environmental factors on radiance measurements which are used to produce spectral reflectance. I have a couple of technical concerns/suggestions and I found a few grammatical errors which I list below.

I really liked figure 4 which explained the various measurement parameters.

The correction technique, equation 10, uses a ratio of radiance measurements for the panel under two different measurement conditions to scale the target reflectance from the measured set of conditions to a new set of conditions.  The panel selected for this study is known to be very Lambertian in its reflectance behavior because it is a bulk scatterer. Doesn’t the correction equation work best when the target material is also Lambertian?

It would be useful to see reflectance figures, like Figure 14, for the correction technique applied to other parameters, such as solar zenith and solar azimuth to provide the reader with additional insight into the success or lack thereof of the correction technique for general application.

Small issues:

Line (54) why is Intensity of Illumination capitalized?  Were you going to define an acronym?

Line (89) I’m not sure I would state that the problem is “fatal.” Perhaps stating that “This has created an issue where the uncertainty results …”

Line (113) Section heading should be 2. not 1.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

First off, a good, relevant, and noteworthy piece of work.

The work has been appreaciated in the form and content.

However, I do suggest several edits.

 

Author Response

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Author Response File: Author Response.pdf