Infrasonic instrumentation at the CEA-DAM: from sensor to network architecture

The CEA-DAM attaches great importance to the control of the measurements it carries out, including for the detection of nuclear tests by geophysical methods. After the design of the first sensors in the late fifties, the various elements of the measurement chains were progressively improved, especially in the field of infrasonic acoustics during the construction of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban treaty (CTBT). The research and development activities carried out in recent years have led, on the one hand, to sensors whose intrinsic noise is significantly lower than the ambient acoustic noises in the most quiet places in the world, and on the other hand to systems that significantly reduce the noise generated by the wind, and to tools for evaluating the performance of a measurement network in order to optimally position the stations on the globe. The ongoing introduction of optical technologies and the growth of metrology activities open up interesting prospects. (authors)