JPSS-2 VIIRS Pre-Launch Reflective Solar Band Testing and Performance
Round 1
Reviewer 1 Report (Previous Reviewer 1)
My comments were addressed by the authors, and I have no more suggestions for changes. I noted, however, that Figure 1 still has issues, e. g. the line below "Scan 1.7864" has two lines of text mixed with each other. At other places the degree sign is at the wrong position.
Concerning line 190: I know that "W" represents "Watt", what I suggested was to write "10,200" or "10200" instead of "10 200".
Author Response
Thank you for the review. My responses to your comments are below.
My comments were addressed by the authors, and I have no more suggestions for changes. I noted, however, that Figure 1 still has issues, e. g. the line below "Scan 1.7864" has two lines of text mixed with each other. At other places the degree sign is at the wrong position.
I've updated figure 1 to fix the issues you mentioned.
Concerning line 190: I know that "W" represents "Watt", what I suggested was to write "10,200" or "10200" instead of "10 200".
There are 10 lamps at 200 Watts not a 10,200 Watt single lamp.
Reviewer 2 Report (Previous Reviewer 3)
Synopsis
This study discusses the pre-launch radiometric calibration of the JPSS-2 VIIRS RSBs SDR. As the launch is JPSS-2 is approaching, this study is beneficial to the calibration scientists and users of this instrument. The methodology is well described, the results are thoroughly discussed, and the manuscript is well written. With some minor edits, this paper should be a solid contribution to the journal.
Minor Comments
· Please make sure the formats of the variables in the equations are consistent with those in the text. E.g., dnSD in equation (1), and dnout in equation (4)
· Line 70: “test” should be “tests”
· Line 197: “are” should be “is”
· Line 274: “covers” should be “cover”
· Line 340: “appear” should be “appears”
· Line 396: missing “a” in front of “fixed”
· Line 400: “shows” should be “show”
· Line 463: “errors” should be “error”
· Line 480: “shows” should be “show”
· Line 501: missing “a” in front of “large”
· Line 565: “is” should be “are”
· Line 593: “is” should be “are”
Author Response
Thank you for the review. My response to your comments is below.
I've reviewed the paper to make the text and equation symbols consistent and updated it with your list of grammatic changes.
Reviewer 3 Report (New Reviewer)
The majority of my comments are in the manuscript PDF, and all are minor. The only substantial issue is with the solar reference spectrum. It looks like you are using one from more than 20 years ago. More recent spectra have much better calibration, particularly in the infra-red. Ultimately, I don't think it's a major contributor to your uncertainty, but it may be something to consider.
All my other comments were very minor.
Comments for author File: 
Comments.pdf
Author Response
Thank you for the review. I've put my responses in the pdf.
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The article gives a good overview of the testing of the reflective solar bands of VIIRS on JPSS-2. There are, however, two weak spots: One is the traceability of the SDRs, the other the calculation of the c2 coefficient. The authors do not explain what "NIST traceable" means. Given the fact that the performance in flight is often different from pre-launch tests, it seems unavoidable that the trace back to NIST is broken with launch. An example is the band to band registration accuracy of SEVIRI (Nain & Mueller, 2019), which is much worse for Met-11 than for all previous Meteosats. Another example: black bodies for microwave sounders have several platinum resistence thermometers, which are diverging from one another during the mission. The manuscript suggests here an accuracy of VIIRS that is not really there, especially when aging enters into the equation as well. The LAA can only improve the precision of c1; the c2 coefficient will still be affected by the lamp's instability. Therefore it will be very difficult to account for non-linear behavior on-orbit. The situation is similar for another infrared instrument, HIRS, where nobody knows what the non-linearity is, and therefore it is simply set to zero in the processing (Cao et al., 2007). I really think the characterization of non-linearity should be improved.
Some minor issues are:
Introduction: The authors define three types of bands with subgroups: RSB (VNIR and SMIR), TEB (SMIR and LWIR), and DNB. Already in Fig. 1, however, they have SWIR instead of SMIR. Why are there two different names for the same group of bands?
Equation 1: contains c0, c1, c2, but these variables are only explained in line 223. The variable "t" is not explained, either.
Figure 1: The text in the figure is hard to read.
Lines 163-165: The NIST-traceable radiance source has an uncertainty of up to 5%, see line 214. This fact alone makes the claim of a radiometric accuracy of 2% in the summary quite dubious.
Lines 185 and 302: What does 10 200W mean? 10 x 200W? 10,200W? The same with 4 200W
Line 211: Explain the abbreviation "RSR".
Line 212: Explain the abbreviation "ASD".
Line 218: Even with LAA one still does not know what the lamp drift is. One only gets the ratio between two fluxes, not their absolute values.
Line 238: What does "relative to the linear term c1" mean? LAA only helps with c1, because one has now only the ratio LAAin/LAAout with high precision.
Lines 247 and 248: If SIS100 introduces a bias that has to be removed by the on-orbit SD calibration anyway, what use does SIS100 have? As written above, one cannot characterize c2 well with an inaccurate SIS100.
Line 320: The requirements margins are not larger for JPSS-2 in case of M6.
Line 336: Obviously Figure 4 is a figure.
Line 394: Should quantization features not manifest themselves in constant distance between the points?
Line 488: c1 does not increase with instrument temperature for all bands.
Line 522: Something seems to be missing between "and" and "as".
Line 526: The abbreviation "OMM" was already explained in line 304.
Line 555: "RSSed" is not an English word.
Table 7: How can the Lunar Cal Error be zero?
Reviewer 2 Report
The manuscript is well written, but it is not like a reasearch paper, review, technical notes or communications. The aim of this journal is "to publish novel / improved methods / approaches and / or algorithms of remote sensing to benefit the community, open to everyone in need of them." This manucript mainly introduce VIIRS and its calibration approaches with little innvation. Although some comparisons of the SDR calibration for RSBs are done, it is still not worth published as a research paper. I think this manuscript is better published as a chapter of a book.
Reviewer 3 Report
Synopsis
This study discusses the pre-launch radiometric calibration of the JPSS-2 VIIRS RSBs SDR. As the launch is JPSS-2 is approaching, this study is beneficial to the calibration scientists and users of this instrument. The methodology is well described, the results are thoroughly discussed, and the manuscript is well written. With some minor edits, this paper should be a solid contribution to the journal.
Minor Comments
1. Line 54: “use” should be “uses”
2. Line 74: “require” should be “requires”
3. Lines 115-116: please rephrase this sentence.
4. Line 381: “a” is redundant in front of “marginally”
5. Line 385: “affects” should be “effects”
6. Line 389 and 391: “shows” should be “show:
7. Line 439: “is” should be “are”
8. Line 455: “indicates” should be “indicate”
9. Line 565: “are” should be “is”
