Extensive Air Shower Reconstruction using the timing information from the RF-system of the Astroneu array

The Astroneu cosmic ray telescope is a distributed hybrid array consisting of both scintillator counters and RF antenna detectors used for the detection of extensive air showers (EAS). The array is deployed at the Hellenic Open University campus, on the outskirts of the urban area of Patras in Greece. In the present development phase, the Astroneu telescope includes two stations consisting of 3 scintillation detectors modules (SDM) and one RF antenna while a third station includes 3 particle detectors and 4 RF antennas (3SDM-4RF). In each station, the RF-detectors are operating receiving a common trigger upon a 3-fold coincidence between the particle detectors of the station. In this study we present recent results from the 3SDM-4RF autonomous station related to the estimation of the direction of the incoming cosmic air shower using only the timing information from the 4 RF detectors. The directions of the reconstructed showers using the RF timing are in agreement with the corresponding results using the SDMs timing as well as with the simulation predictions. This verifies that the RF signal emitted from EAS originating form Ultra High Energy Cosmic Rays (UHECR), can be detected even in areas with strong electromagnetic background.

Potential Non-Invasive Technique for Accessing Plant Water Contents Using a Radar System

Sap flow measurements of trees are today the most common method to determine evapotranspiration at the tree and the forest/crop canopy level. They provide independent measurements for flux comparisons and model validation. The most common approach to measure the sap flow is based on intrusive solutions with heaters and thermal sensors. This sap flow sensor technology is not very reliable for more than one season crop; it is intrusive and not adequate for low diameter trunk trees. The non-invasive methods comprise mostly Radio-frequency (RF) technologies, typically using satellite or air-born sources. This system can monitor large fields but cannot measure sap levels of a single plant (precision agriculture). This article studies the hypothesis to use of RF signals attenuation principle to detect variations in the quantity of water present in a single plant. This article presents a well-defined experience to measure water content in leaves, by means of high gains RF antennas, spectrometer, and a robotic arm. Moreover, a similar concept is studied with an off-the-shelf radar solution—for the automotive industry—to detect changes in the water presence in a single plant and leaf. The conclusions indicate a novel potential application of this technology to precision agriculture as the experiments data is directly related to the sap flow variations in plant.

Dedicated 70 MHz RF systems for hyperthermia of challenging tumor locations

Hyperthermia (i.e. heating of tumor tissue to 40–43°C) is used in clinical oncology to enhance the therapeutic effect of chemotherapy and radiotherapy. Many tumor sites are heated either by a single RF or MW antenna positioned on the tumor location, or by a phased array positioned around the patient. Superficial tumors are generally heated with MW antennas (434–2450 MHz) and deep-seated tumors with RF antennas (70–150 MHz). These devices cover the major, more common tumor sites, but more rare locations require more dedicated applicators. We discuss dedicated RF systems aiming for heating semi-deep-seated tumors in the leg, breast, and upper thorax. Clinical results show that adequate heating is possible with these systems, with achieved temperatures in the therapeutic range.

Intra-Chip and Inter-Chip Wireless Communication Analysis for Millimeter Wave using Miniaturized On-Chip Antenna

System on Chip (SoC) is an emerging technology for semiconductor devices that aims for better compaction with reduced interconnects, RC delay, noise, and power consumption. Wired connections between chips, ICs or SoC’s lead to increased heat dissipation, which is undesirable. Hence, mechanisms have been developed for making communication between the chips wireless and use of miniaturized RF antenna is inevitable. In this paper, to analyse the performance of wireless communication over millimeter range, millimeter scale RF antennas operating at frequencies of 20 GHz to 70 GHz are considered. Using ANSYS HFSS software, the scenario for intra and inter chip wireless communication is established using the bowtie antenna operating around 50 GHz and their performance evaluation is done considering the various parameters. An intrachip system of four bowtie antennas is simulated around 50GHz and the S-parameters are plotted and analysed

Hyperspectral Microwave Atmospheric Sounder (HyMAS) Graphical User Interface Design

The hyperspectral microwave atmospheric sounder (HyMAS), for weather and climate missions, is capable of all-weather sounding equivalent to hyperspectral infrared sounders (in which clouds decrease the accuracy of the results) in clear air with vertical resolution of approximately 1 km. This will improve both the vertical and horizontal resolutions of the atmosphere. Through the use of independent RF antennas that sample the volume of the Earth's atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions, hyperspectral microwave is achieved. This yields surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with high accuracies. One of HyMAS requirements is a graphical user interface (GUI). Hyperspectral measurements allow the user to determine the Earth's temperature with vertical resolution exceeding 1km (1093.61 yards).

Studies for high energy air shower identification using RF measurements with the ASTRONEU array

The Hellenic Open University (HOU) Cosmic Ray Telescope (ASTRONEU) consists of 9 large scintillator detectors and 3 RF antennas arranged in three autonomous stations operating at the Hellenic Open University campus in the city of Patras. High energy showers that are detected simultaneously by two distant stations and in coincidence with the RF antennas are used to study the RF signature of cosmic events. In previous studies we have shown that the timing of the RF signals as well as the measured electric field at the antennas position are in very good agreement with the simulation predictions. In this work we concentrate on the transfer functions of the antennas which are strongly frequency and angular dependent. We show that the RF spectra (at frequencies 30-80 MHz) of the detected showers are exhibiting features of the antenna response as predicted by detailed Monte Carlo simulation suggesting that a single antenna RF spectrum gives access to the cosmic ray arrival direction.

Hybrid Detection of High Energy Showers in Urban Environments

The Astroneu array comprises 9 large charged particle detectors and 3 RF antennas arranged in three autonomous stations operating at the University Campus of the Hellenic Open University in the city of Patras. Each station of the array detects extensive air showers with primary energy threshold of about 10 TeV, while double station coincidence events select showers with energies higher than 10 3 TeV. In such an environment, the radio detection of air showers is challenging. The RF signals besides being extremely weak they also suffer from strong human made electromagnetic noise. In this work, we present the analysis of double station coincidence events and we study the correlation of the RF data with the particle detectors data. We use the experimental information from the particle detectors and the antennas to select very high energy showers and we compare the timing of the RF signals with the timing of the particle detector signals as well as the strength of the RF signals with the simulation predictions.