An Overall Assessment of JPSS-3 VIIRS Radiometric Performance Based on Pre-Launch Testing

Round 1

Reviewer 1 Report

This is a well-written paper containing valuable results which merit publication. For the benefit of the reader, however, several points need clarifying and certain statements require further justification. There are given below.

1. There're two errors in table1, such as "119" instead of "352?" and "I3" instead of "13" 

2. In line 232, the full name “Analog Signal Processor” should be given before the abbreviation “ASP” 

3. In line 351, the full name “cold focal plane assembly” should be given before the abbreviation "CFPA"

4. Why the "Lscat/Lspec" value about band M16 is a little higher than the earlier builds in table 9?

5. In the section “Polarization”, why the number of negative scan angles is far more than that of positive scan angles?

Author Response

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Reviewer 2 Report

The manuscript describes the results of the pre-launch testing of the VIIRS fourth build to be launched on JPSS-3. The detailed description of the radiometric performance with the applied metrics as well as the comparison with the previous builds of the same series is surely a valuable reference for the community of earth observation. I would like to recommend its publication after considering the following minor, mostly editorial comments.

• The sub-section title "2.1.1 Sensor Design Changes" could be removed as there exists no sub-section 2.1.2. The contents of the current 2.1.1. can simply a paragraph of section 2.1.
• The bracket in line 155-156 of section 2.2 should be removed.
• The acronym TOA used in line 195 and elsewhere is not defined. 
• Adding a sentence defining the coefficients c₀, c₁, and c₂ in the first paragraph of section 3.1 is recommendable.
• The square bracket in line 346 should be removed and the units should be changed to non-italic. 
• The acronym CFPA used in line 351 and elsewhere is not defined (while FPA is defined in line 51).
• The term CPFA in line 406 should be a typo of CFPA.
• The acronym ASP used in line 383 is not defined.
• The acronym OBCBB used in line 456 is not defined.
• The references [10] and [18] should be the same, so one of them needs to be corrected.

Author Response

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Reviewer 3 Report

Dear Authors,

Your paper, "An Overall Assessment of JPSS-3 VIIRS Radiometric Performance Based on Pre-launch Testing" is intended to become a valuable source of information for researchers who plan to use the data of the VIIRS in the future and will have to perform detailed error analysis for the algorithms used to process this data. In general, the paper provides comprehensive information about the results of ground pre-launch testing. Despite all this, the paper is quite difficult to read due to the large number of abbreviations (36), among which more than 20 are not generally accepted (like, for example, NASA or NOAA). I mean the following abbreviations: FPA, RSB, TEB, DNB, HG, LG, LSS, MSG, HGS, HGA, HGB, SDSM, RTA, EFL, HAM, RSR, NFR, ASP, ARD, OBCBB, IOOB, RVS. Of course, all these abbreviations are once described in the text (with the exception of the ASP), but it would be more convenient for the reader to see them all on one page, in the appendix to the main text of the paper.

It is necessary to add at least a brief description of what aggregation modes are to the text of paper.

I also noticed the following typos:
Line 94, it seems to me that the word "transition" should be replaced with the verb "transit" or "make transition"
Line 301, please replace "ob-orbit" with "on-orbit"
In table 1, in line 9 (for band I1 with gain HG), in the last column there is an extra question mark.
In addition, in the same table, in the row for DNB with gain HGS, in the number Lmin, the letter E should be replaced with a multiplication sign.

From my point of view, the minimum revision of the article should include a description of what aggregation modes are and an explanation for the abbreviation ASP.

Sincerely yours,
Your Reviewer.

Author Response

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Reviewer 4 Report

This work describes in detail the pre-flight performance of the fourth build of the Visible Infrared Imaging Radiometer Suite (VIIRS), which will be launched in JPSS-3. The paper is well structured, well written and contains relevant material for the remote sensing community. A number of changes are recommended below to help improve the clarity of the work and its usefulness both for the general reader and for the potential new user of VIIRS data.

A. Section 2.1, lines 63-69. Some instrument characteristics are apparently missing in the description, e.g. the maximum off-nadir angle of observation, the typical number of across-track pixels or the length of datatakes. A short description of these points would improve the description of VIIRS in Section 2.1. It would also be useful to know the planned mission life time for JPSS-3 VIIRS.

B. Section 2.1, lines 90-103. The frequencies for blackbody and  solar diffuser calibrations are mentioned, but not the frequency for deep space calibrations. Please add this information.

C. Section 2.1, Table 1. I would recommend to include a short reasoning for the chosen gain configuration of the different bands (Table 1) and discuss the differences (if any) with respect to previous builds. For instance, why is M6 only on high gain? Or why is M13 in both high and low gain while all other thermal bands in high gain only? This is not immediately apparent to the reader.

D. Section 3.1.3, line 259. It is mentioned that the SNR values listed in Table 4 are band averages. How do the distributions look like? It would be useful to show these distributions at least for some bands.

E. Section 3.1.4, line 268. Although the RSB detectors showed compliance for uniformity and the expected striping is low, it would nevertheless be useful to show the measured detector-to-detector uniformity in form of tables or plots.

F. Section 3.2. Although mentioned several times in the text and also in Figure 2, I did not manage to find details or explanations about the aggregation modes for DNB. Please add a short discussion on this.

G. Section 3.2.2. The SNR for the minimum radiance in DNB was obtained by extrapolation of the two lowest radiance levels, but no details are given about the extrapolation used. Was it a linear extrapolation? It would also be useful to show one example plot of the SNR as a function of radiance level for this case.

H. Section 3.3. I would suggest to include a plot of the c0, c1 and c2 coefficients for the thermal bands, similarly to Figure 1 for RSB coefficients. This would provide the reader with more quantitative information about the radiometric performance of these bands.

I. Section 3.4.4. Table 9 contains no NFR results for bands M9 and M14. I could not find the reason for this in the text. A short explanation should be given for the benefit of the reader.

J. Section 4. Although not the main topic of this paper, it would be useful to shortly mention how the interested user may access JPSS-3 VIIRS data in the future and the different processing levels available.

K. References. Although some degree of self-citation is unavoidable in a paper like this one, I would advise the authors to revise the referenced work. Please make sure that all VIIRS references cited are actually relevant to the reader and that reference to other remote sensing instruments complementary or similar to VIIRS are included.

Author Response

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