I can't believe noone has mentioned NRO and NGA:

https://en.wikipedia.org/wiki/National_Reconnaissance_Office

https://en.wikipedia.org/wiki/National_Geospatial-Intelligen...

Relatively less is known about them, since CIA and NSA get all the attention lately (to their detriment), but as far as we can tell (from Snowden docs), NRO has about equal budget to NSA, and NGA has about half (and CIA has 1.5 times NSA's):

http://www.washingtonpost.com/world/national-security/black-...

Considering the incredible things NSA has been able to do with its $10B/yr, a combined NRO+NGA budget of $15B/yr sure raises a lot of questions. Presumably, they do a lot of work similar to the OP's - but noone really know what the capabilities are.