Dear authors,

based on the evaluation of your revised manuscript, I would like to accept your paper for publication, subject to technical corrections. Please find the corrections provided by the reviewers of the revised manuscript below.

Best regards
Lars Hoffmann

Technical corrections by Reviewer #2
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p. 5, l. 108: ...from the thousands of channels' observations... please rephrase, but I have no suggestions
p. 8, l. 155: Channel selection mostly uses the information content and delievers the largest amount of information for the selected channel combination during the retreival.
p. 9, l. 194: after the retrieval
p. 11, l. 236: (2) The number looks like an equation number, so it is a bit confusing
p. 18, l. 389: The footprint size is 13.5 km
p. 19, l. 401/402: in Fig. 1. The measurement error is not below 0.2K for all the instrument channels. There are...
p. 21, l. 434: ranking -> in the range
p. 27, l. 532: temperature, a better observation can be obtained for higher temperatures
p. 28, l. 547: to the -> at
p. 30, l. 567: reach to -> reaches
p. 36, l. 650: humidity and 10m wind speed (remove dot after speed)
p. 43, l. 778: to the -> at

Technical corrections by Reviewer #4
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p1, l16-20: Suggest to replace the first two sentences of the abstract by: "This study introduces an effective channel selection method for hyperspectral infrared sounders. The method is illustrated for the Atmospheric InfraRed Sounder (AIRS) instrument."
p1, l21: "improved method" -> "improved channel selection (ICS) method"
p2, l24: suggest to delete "and closer to the actual atmosphere"
p2, l30: suggest to replace "In general, ..." by "Also at lower heights, ..."
p2, l31-32: delete "(Improved Channel Selection)"
p2, l32-36: suggest to rephrase this as "Statistical inversion comparison experiments for four different regions illustrate latitudinal and seasonal variations and better performance of ICS compared to the NWP Channel Selection (NCS) and Primary Channel Selection (PCS) methods. The ICS method shows potential for future applications."
p4, l70: please fix: "Infrared Atmospheric Sounding Interferometer"
p5, l110: replace "the channel selection algorithm" by "channel selection algorithms"
p11, l236: replace "p matrix" by "for calculating the p value"?
p11, l237: replace "matrixes, it" by "matrices, they"
p12, l257: replace "According to" by "Using"
p18, l383: The reference to Hoffmann and Alexander (200) can be deleted here, I think. Maybe move reference to Susskind et al. (2003) from line 389 to this place.
p27, l515-534: Suggest tp delete all the sentences relating the wavelengths to the wavenumbers, as this is trivial. For instance, replace "When the wavenumber approaches 1000... Near this band..." by "Near the 10 um band..."
p27, l529-533: It is still not clear what is meant by "high temperature zone", I think. Does this refer to temperatures at high altitudes?
p28, l537: replaced "used in this paper" by "considered in this study"
p29, Fig. 5: I would like to suggest to combine the curves of plot a) and b) into a single plot.