SAFIRE: A close range real time millimetre wave radar for public education

Millimetre wave (MMW) imaging is a fast moving technological area which has seen major advances in the last few years and is now offering practical solutions across a wide spectrum of imaging applications. Despite this, the technology is largely unknown and poorly understood by the general public. Under a UK EPSRC partnership for public engagement grant, the millimetre wave group at the University of St Andrews has partnered with exhibit development company FifeX Ltd to construct a touring exhibition designed to showcase the alternative view of the world provided by MMW remote sensing, illustrating the science principles behind the technology. The group is providing the centrepiece of the programme, a 94 GHz FMCW radar named SAFIRE (St Andrews fast imaging radar equipment). SAFIRE uses a frequency multiplied 7G Hz source to provide a low power (+2.5 dBm) 94 GHz carrier with a 750 MHz modulation bandwidth (i.e. a radar range resolution of 0.2 m). SAFIRE has a single zenith-pointing antenna scanned in azimuth via a rotating mirror angled at 45 degrees to the antenna axis to generate a PPI display of the immediate scene surrounding the radar (the maximum range is 25 m). Since real time imagery is essential for a project of this type the PPI is refreshed at minimum rate of 4 Hz. We present an outline of the motivation for the radar design and the expected system performance.