This page from GCHQ’s internal GCWiki, last updated on 1 May 2012 documents progress in a variety of the agency’ projects: see Facing Data Deluge, Secret U.K. Spying Report Warned of Intelligence Failure, 7 June 2016.
This GCHQ research report dated 20 September 2011, cowritten by researchers at Heilbronn Institute for Mathematical Research based at the University of Bristol, concerns the use of data mining techniques to develop usable intelligence as well as the contradictions that arise from the use of algorithms to identify wrong doers, or potential wrong doers. The paper also provides a great deal of background information on GCHQ operations and the detailed discussion of network theory demonstrates the power of metadata collection: see the Boing Boing article Doxxing Sherlock, 2 February 2016.
This January 2011 article from Northwest Passage, the NSA internal newsletter for the Yakima Research Station gives an account of its history, including its involvement in ECHELON: see the Intercept article GCHQ and Me: My Life Unmasking British Eavesdroppers, 3 August 2015.
This page taken from a longer 2 July 2010 GCHQ report on the state of its COMSAT capabilities (against communications satellites) confirms that “NSA has historically been a large source of funding” for this aspect of the agency’s activies: see the Intercept article GCHQ and Me: My Life Unmasking British Eavesdroppers, 3 August 2015.
This two-page extract from a longer, undated, GCHQ document describing its presence in Cyprus, states that “Under the ECHELON Agreement, NSA provides 50% of the funding for the SOUNDER Comsat facility”: see the Intercept article GCHQ and Me: My Life Unmasking British Eavesdroppers, 3 August 2015.
This GCSB presentation dated 21 March 2012 shows that the Waihopai listening station’s main target was a satellite based above the Kiribati islands: see the Sunday Star Times article Snowden files: Inside Waihopai’s domes, 8 March 2015.
This undated GCHQ presentation introduces the FLYING PIG and HUSH PUPPY tools: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.
This undated article from GCHQ’s internal GCWIki gives technical details about the US-German Joint Sigint Activity group: see the Der Spiegel article New NSA Revelations: Inside Snowden’s Germany File, 18 June 2014.