Central Australia's Pine Gap spy base played a key role in the United States' controversial drone strikes involving the ''targeted killing'' of al-Qaeda and Taliban chiefs, Fairfax Media can reveal.
Former personnel at the Australian-American base have described the facility's success in locating and tracking al-Qaeda and Taliban leaders - and other insurgent activity in Afghanistan and Pakistan - as ''outstanding''.
A Fairfax Media investigation has now confirmed a primary function of the top-secret signals intelligence base near Alice Springs is to track the precise ''geolocation'' of radio signals, including those of hand-held radios and mobile phones, in the eastern hemisphere, from the Middle East across Asia to China, North Korea and the Russian far east.
This information has been used to identify the location of terrorist suspects, which is then fed into the United States drone strike program and other military operations.
The drone program, which has involved more than 370 attacks in Pakistan since 2004, is reported to have killed between 2500 and 3500 al-Qaeda and Taliban militants, including many top commanders.
But hundreds of civilians have been also killed, causing anti-American protests in Pakistan, diplomatic tensions between Washington and Islamabad and accusations the ''drone war'' has amounted to a program of ''targeted killing'' outside a battlefield. This year, the Obama administration acknowledged four American citizens had been killed by strikes in Pakistan and Yemen since 2009.
''The [Taliban] know we're listening but they still have to use radios and phones to conduct their operations; they can't avoid that,'' one former Pine Gap operator said. ''We track them, we combine the signals intelligence with imagery and, once we've passed the geolocation [intelligence] on, our job is done. When drones do their job we don't need to track that target any more.''
The base's direct support of US military operations is much greater than admitted by Defence Minister Stephen Smith and previous Australian governments, new disclosures by former Pine Gap personnel and little-noticed public statements by US government officials have shown.
Australian Defence intelligence sources have confirmed that finding targets is critically dependent on intelligence gathered and processed through the Pine Gap facility, which has seen ''a massive, quantitative and qualitative transformation'' over the past decade, and especially the past three years.
''The US will never fight another war in the eastern hemisphere without the direct involvement of Pine Gap,'' one official said.
Last week, secret documents leaked by US whistleblower Edward Snowden indicated Pine Gap also contributes to a broad US National Security Agency collection program codenamed ''X-Keyscore''.
Pine Gap controls a set of geostationary satellites positioned above the Indian Ocean and Indonesia. These orbit the earth at fixed points and are able to locate the origin of radio signals to within 10 metres. Pine Gap processes the data and can provide targeting information to US and allied military units within minutes.
Former US National Security Agency personnel who served at Pine Gap in the past two years have described their duties in unguarded career summaries and employment records as including ''signals intelligence collection, geolocation … and reporting of high-priority target signals'' including ''real time tracking''.
US Army personnel working at Pine Gap use systems codenamed ''Whami, SSEXTANT, and other geolocation tools'' to provide targeting information, warnings about the location of radio-triggered improvised explosive devices, and for combat and non-combat search and rescue missions.
Pine Gap's operations often involve sifting through vast quantities of ''noise'' to find elusive and infrequent signals. One former US Army signals intelligence analyst describes the ''collection and geolocation of an extremely hard to find target'' as a task that included ''manually sifting through hundreds of hours of collection''.
Last month Mr Smith assured Parliament that Pine Gap operates with the ''full knowledge and concurrence'' of the government.
He provided no details other than to say the facility ''delivers information on intelligence priorities such as terrorism, the proliferation of weapons of mass destruction, and military and weapons developments'' and ''contributes to the verification of arms control and disarmament agreements''.
The government is required by a number of agreements to consult with the US government before the public release of any new information about Pine Gap.
The federal government maintains a long-standing policy of not commenting on operational intelligence matters.