Review Reports

Round 1

Reviewer 1 Report

This study presents an assessment of the uncertainties of measured soil emissivity across different wavelengths using measurements from different sensors and laboratories. The study quantifies and demonstrates the implications of these uncertainties in estimating surface temperature, which has vast implications for remotely sensed Earth Observation. The paper is well written, the experiment is well documented, the results are extensively presented and discussed. I recommend the paper for publication.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors compared the spectral emissivity of same samples in laboratories all over the world with their diverse FITR instruments. They showed a huge effort in organizing this round-robin study. As far as the reviewer is aware, similar studies are not already present in the literature, so the paper offers a motivating novelty aspect. This paper is clearly organized, well presented and exhaustive, but some typos are present and the numbers of figures are not noted correctly, which leads a difficulty to follow the authors’ ideas.

Some points need to be clarified:

1. The authors have compared the results from different laboratories and calculated the mean value and standard deviation. But in the same laboratory, the measurement has been carried out only one time, although several instruments gave the number of averaging scans.? If not, it can reach which level of the measurement stabilization?
2. Between testing the reference sample and the sample to examine, how did all laboratories keep the source energy identical? Except like KCL measured the reflectance of the “wall”?
3. The duration of each measurement is missing in this paper. The light source may heat the sample if the sample exposed long time under the radiation.
4. The land surface is usually less reflective than the sample that the authors prepared. I can understand that in the chamber of FTIR instruments, one needs a sample reflecting enough light to have a good measurement, but they are not representative for the real case. That’s why in the last section, the authors have inaccurate temperatures with the sample 1 and 2. The highlight of this paper is providing a new path to get the emissivity by FTIR spectrometers and comparing the different instruments and experimental protocols. By this method, the spectral emissivity will be calculated accuratly with further correction and proper samples. Therefore, I recommend that the section 3.4 can be removed from this paper.
5. Caption of Figure 2 (line 183), a part of text is mixed inside.

Some typo mistakes:

Line 96 “Whist the former ‘thermal  emission’  approach  is used…”

Line 192 “distilled water have already been used in in other”

Line 202 “The Aglient does not have an…”

Line 463 “Given that the shifts are observed for the specular sample only and that they were”

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors,

It was a pleasure to review this manuscript. My comments are in the attached file.

Best regards

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

This paper is well contructed and the idea of collabrative comparaision in such large number of laboratories is quite attractive. 

The authors modified the text and anwsered to my question correctly. 

I am convinced that this paper merits to be published.