In their TCD manuscript “The Pléiades Glacier Observatory: high-resolution digital elevation models and ortho-imagery to monitor glacier change” Berthier et al. introduce a contentiously growing topographic dataset of 140 glacierized areas around the world termed the Pléiades Glacier Observatory (PGO). For each region, one Pleiades stereo acquisition is acquired every 5 years to monitor the glacier's state and health at the globally distributed benchmark sites. The data will be processed to Digital Elevation Models (DEMs) and orthoimagery and will be made publicly available.

This is a very valuable dataset for the glaciological society to document ongoing glacier changes around the world and I want to thank the authors for making this happen. Overall the manuscript is well structured and written and I suggest publication after correcting some minor points which I list in the following.

Specific comments:

L19-20: short general information about the Pleiades satellite mission should be included in the abstract.

L27-28: is this shown in the manuscript? (Well, yes in section 4) Can you quantify it here?

L39: what about InSAR and altimetry? Maybe include a brief intro in this paragraph or at least that these methods also exist?

L73: here also Holzer et al., 2015 could be cited

L77-81: this is important and I and probably the entire glaciological community are very thankful for your efforts.

L185: What are the specifications of the Copernicus GLO-30 DEM (e.g. resolution (from the naming I guess 30 m...), accuracy etc.)?

L239: off-glacier I presume, but maybe write it explicitly.

L246-L248: I agree with this point and it also raises the question why the authors did not coregister to a more precise dataset such as ICESat/ICESat-2 altimetry? Is there a particular reason? I could imagine track spacing and surface slope are an issue?

L396: what is GTN-G again?

Additional References:

Holzer, N., Vijay, S., Yao, T., Xu, B., Buchroithner, M., and Bolch, T.: Four decades of glacier variations at Muztagh Ata (eastern Pamir): a multi-sensor study including Hexagon KH-9 and Pléiades data, The Cryosphere, 9, 2071–2088, https://doi.org/10.5194/tc-9-2071-2015, 2015.

See pdf for review.

The formal manuscript rating questions emphasize "scientific understanding," which is challenging/ambiguous for this manuscript, as the focus is on methods and new data products, rather than new cryosphere science.  The PGO data products will likely have significant impact for the science community moving forward, but this manuscript does not directly include any significant/high-impact science. Hopefully that makes sense - see detailed review for further comments on this topic.