Millimeter-wave (mmWave) radars have found applications in a wide range of domains, including human tracking, health monitoring, and autonomous driving, for their unobtrusive nature high accuracy. These capabilities, however, if used malicious purposes, could also result serious security privacy issues. For example, user's daily life be secretly monitored by spy radar. Hence, there is strong ur...

Near-space, defined as the region between 20 km and 100 km, offers many new capabilities that are not accessible to low earth orbit (LEO) satellites and airplanes, because it is above storm and not constrained by either the orbital mechanics of satellites or the high fuel consumption of airplanes. By placing radar transmitter/receiver in near-space platforms, many functions that are currently p...

The proposed Low Frequency Array will be a powerful new radio telescope operating in the 15 to 240 MHz range. LOFAR will be a fully digital instrument with tens of thousands of antennas and receivers. In the currently proposed configuration LOFAR will also be capable of operating as a high performance passive radar system using FM radio stations as signals of opportunity. In this mode of operat...

Atmospheric scientists need to observe fluctuations in the ionosphere, both to probe the underlying atmospheric physics, and to remove the effects of these fluctuations from other measurements. We have built an FPGA-based, pipelined array processor that allows us to make these observations in real-time, using passive radar techniques. Our array processor time-multiplexes 16 multiply–accumulator...