Another well written and interesting document (Im sure all 3 are). Another small change suggested:

in final paragraph of section 2, mention both MODIS and AIRS WCS servers. Only AIRS server is mentioned here, only MODIS in 3.1, and both are acknowledged in 3.3. Better to introduce both up front.

After reading this document, my question is why would you put an OPeNDAP server on top of WCS instead of directly on top of the data? If you have to stand up both servers anyway, what is the advantage of chaining them, esp. since the two servers have different functions aimed at different user communities (as discussed in into section). I can make some guesses as to why WCS + OPeNDAP might be better than two separate implementations in this case, but it would be nice to have that spelled out.