We report on an integrated Hartmann wavefront sensor (WFS) using passive-pixel architecture and pixels clustered as position-sensitive detectors for dynamic wavefront analysis. Such a device detects the degrees of imperfection (aberrations) of a light beam by measuring the deviation of the incoming wavefront from a reference one. It can be employed either as a diagnostic tool, or in close loop ...

For a passive direction of arrival (DOA) measurement system using massive multiple input output (MIMO), it is mandatory to infer whether the emitter exists or not before performing DOA estimation operation. Inspired by detection idea from radio and ranging (radar), three high-performance detectors are proposed existence single eigen-space sample covariance matrix receive signal vector. The firs...

Passive acoustic monitoring is a promising approach for monitoring long-term trends in harbor porpoise (Phocoena phocoena) abundance. Before passive acoustic monitoring can be implemented to estimate harbor porpoise abundance, information about the detectability of harbor porpoise is needed to convert recorded numbers of echolocation clicks to harbor porpoise densities. In the present study, pa...

An intercomparison exercise for passive integrating radon detectors has been carried out with the participation of 12 detection systems from 10 laboratories. The detection systems comprise three commonly used in radon integrating measurements, tracks, activated charcoal canisters and electrets. The exposures were carried out in the radon and thoron chambers at the Institute of Energy Techniques...

Visual displays in passive sonar based on the Fourier spectrogram are underpinned by detection models that rely on signal and noise power statistics. Time-frequency representations specialised for sparse signals achieve a sharper signal representation, either by reassigning signal energy based on temporal structure or by conveying temporal structure directly. However, temporal representations i...

One of the aims of the First Intercomparison on Natural Radioactivity Under Field Conditions was to test different instruments and detectors for the measurement of radon gas and external gamma radiation (dose rate) in filed conditions, where the levels of natural radiation are quite high. The event was organized by the Radon group of University of Cantabria, (Spain) LaRUC, and was held in the e...

In this paper a study of waveguide photodetectors based on InAs/InP(100) quantum dot (QD) active material are presented for the first time. These detectors are fabricated using the layer stack of semiconductor optical amplifiers (SOAs) and are compatible with the active-passive integration technology. We investigated dark current, responsivity as well as spectral response and bandwidth of the d...

Second generation gravitational wave detectors require high power lasers with more than 100 W of output power and with very low temporal and spatial fluctuations. To achieve the demanding stability levels required, low noise techniques and adequate control actuators have to be part of the high power laser design. In addition feedback control and passive noise filtering is used to reduce the flu...

We are starting to investigate a novel multiplexable readout method that can be applied to a large class of superconducting pair-breaking detectors. This readout method is completely different from those currently used with STJ and TES detectors, and in principle could deliver large pixel counts, high sensitivity, and Fano-limited spectral resolution. The readout is based on the fact that the k...

We report on the construction and laboratory testing of pixellated CZT detectors mounted in a flip-chip, tiled fashion and read out by an ASIC, as required for proposed hard X-ray astronomy missions. Two 10 mm × 10 mm × 5 mm detectors were fabricated, one out of standard eV Products high-pressure Bridgman CZT and one out of IMARAD horizontal Bridgman CZT. Each was fashioned with a 4 × 4 array o...