Monitoring or Intelligence Gathering?

The infrasound signals from North Korea’s 4 July 2006 missile launch.

Infrasound has become an accepted CTBT monitoring technique in recent years with 60 infrasound stations world-wide as part of the CTBTO network. They also, however, detect a bunch of other atmospheric phenomena, as Bharath Gopalaswamy has illustrated. I am particularly interested in using these facilities (or perhaps I should say this phenomena) to study missile proliferation and have worked with Bharath on just this question. In particular, I think it would be useful to determine when North Korea’s 2006 Tae’podong-2 failed or Iran’s August 2008 Safir launch failed. (The analysis has proved complicated with one acoustic event, such as the staging of the rocket, potentially showing up at several different times in the recorded signal. Each time corresponds to a different acoustic flight path such as 3 vs. 4 bounces off the stratosphere. Since a rocket trajectory consists of a number of such acoustic events, it becomes fairly complicated to unwrap the signal; especially since the timing depends on wind speeds and directions and could vary for the different paths. I hope to post more about this analysis as we progress.)

This helps illustrate how one person’s useful technique for detecting clandestine nuclear explosions is another’s intelligence gathering. In particular, I understand that India considers this nothing but an intelligence gathering exercise. Should the international community deny itself such a useful tool because it could be used to gather information about a country’s missile development? Or should countries recognize that firing a rocket is an inherently open process and that certainly their neighbors could set up their own infrasound stations and monitor what is going on regardless of whether or not the international community does? And, of course, the US and perhaps Russia are observing the rocket launches with infrared-sensitive satellites.

You can probably guess which way I come down on this question. I might also mention that if the CTBT actually goes into force, people like me will no longer be able to access any of the information from any of the CTBTO stations, including seismic signals. That’s what the treaty says. So public scrutiny of missile proliferation will, hopefully, be denied this important tool. But governments who sign the CTBT will be able to use it so the question is still important for policy makers.