Thank-you for your revised version of the manuscript and response to the comments of the two referees. Given that the referees had very different recommendations (technical corrections vs. major revisions), I requested a review by a third referee. After carefully reviewing the manuscript and your comments, this referee recommends publication after minor revisions. Please consider this referee's comments and submit a point-by-point response along with a further revision of the manuscript.

Thank-you
Kim Strong

Thank-you for your detailed response to reviewer 3. The revised manuscript is ready for publication after a technical correction related to Figure 4.

Although the figure caption has been revised, I think some additional clarification is needed. The TCCON, GOSAT, and OCO-2 labels can easily be misinterpreted to imply that their actual precisions are as indicated, when this figure is only showing results for a single absorption line, which is very different from their spectral sampling. The caption tries to address this with the concluding sentence: "The spectral resolutions of TCCON (Wunch et al., 2011), satellite GHG sensing spectrometers (Kuze et al., 2009; Connor et al., 2008) and the CO2 Sounder instrument are indicated, though the calculations done in this work apply only to the CO2 Sounder instrument." but this still leaves room for misunderstanding.

Please look up the actual precisions for the three and change this sentence to:
"The spectral resolutions of TCCON (Wunch et al., 2011), satellite GHG sensing spectrometers (Kuze et al., 2009; Connor et al., 2008) and the CO2 Sounder instrument are indicated, however, these results apply only to the specific case of a wavelength sampling scheme sampling a single absorption line, i.e., the CO2 Sounder lidar sampling scheme. The actual precisions are XXX for TCCON (add ref.); YYY for GOSAT (add ref.), and ZZZ for OCO-2 (add ref.)."