Embedded Software of the KM3NeT Central Logic Board

The KM3NeT Collaboration is building and operating two deep sea neutrino telescopes at the bottom of the Mediterranean Sea. The telescopes consist of latices of photomultiplier tubes housed in pressure-resistant glass spheres, called digital optical modules and arranged in vertical detection units. The two main scientific goals are the determination of the neutrino mass ordering and the discovery and observation of high-energy neutrino sources in the Universe. Neutrinos are detected via the Cherenkov light, which is induced by charged particles originated in neutrino interactions. The photomultiplier tubes convert the Cherenkov light into electrical signals that are acquired and timestamped by the acquisition electronics. Each optical module houses the acquisition electronics for collecting and timestamping the photomultiplier signals with one nanosecond accuracy. Once finished, the two telescopes will have installed more than six thousand optical acquisition nodes, completing one of the more complex networks in the world in terms of operation and synchronization. The embedded software running in the acquisition nodes has been designed to provide a framework that will operate with different hardware versions and functionalities. The hardware will not be accessible once in operation, which complicates the embedded software architecture. The embedded software provides a set of tools to facilitate remote manageability of the deployed hardware, including safe reconfiguration of the firmware. This paper presents the architecture and the techniques, methods and implementation of the embedded software running in the acquisition nodes of the KM3NeT neutrino telescopes

Fast estimation of MPPs in mismatched PV arrays based on lossless model

In this paper a direct method to estimate maximum power points (MPPs) in PV arrays subjected to mismatching conditions is presented. The method uses the lossless single-diode model (SDM) which is parameterized using the data of inflection and maximum power points of each panel. The reconstruction of power vs. voltage curve is obtained by one explicit equation, thus avoiding the use of recursive non-linear equations solver. The performance of this technique has been validated in terms of computation time and accuracy by means of the comparison with other existing methods

Optimized Configuration of Mismatched Photovoltaic Arrays

When the panels in a photovoltaic (PV) array are subjected to a nonuniform irradiance level, some bypass diodes may turn ON, and the overall power production might be affected significantly. An increase of the power delivered by the whole array might be obtained by means of its electrical reconfiguration, that is, the change of the series–parallel connection among the panels of which it is made up. The computation of the electrical connection among the panels that ensures the maximum delivered power is a combinatorial problem requiring powerful optimization methods. This paper is devoted to the formulation of an optimization procedure for determining the best electrical configuration among the panels. The proposed algorithm requires simple mathematical calculations, and it uses a vectorized structure; thus, it is suitable to be implemented in any embedded system for the purpose of a real-time PV array reconfiguration. The algorithm is first explained by using a pilot example, and afterward, its performance is shown by applying it to a real domestic PV field. The results show that the optimization algorithm computes an optimized configuration with a low computational burden

Enhanced simulation of total cross tied photovoltaic arrays

A photovoltaic field is classically made of parallel connected strings, each one formed by a number of series connected modules. The total cross tied interconnection, which adds string-to-string wires, allows to increase the harvested energy when non-uniform operating conditions, like partial shadowing, occur. The simulation of mismatched total cross tied photovoltaic fields is mandatory to predict the increase of the power production accurately and for designing the proper power processing stage for the maximum power point tracking function. A fast and accurate simulation is also useful for model-based diagnostic purposes. In this paper an effective simulation model, which profits from a peculiar sparsity pattern of the system of non linear equations for achieving a very short computation time, is presented. It can be implemented in any platform and it has high potentialities also to be ported on embedded systems for real time simulation

VizieR Online Data Catalog: Gaia16aye microlensing event photometry (Wyrzykowski+, 2020)

Photometric data for the microlensing event Gaia16aye. We present three separate tables with the follow-up data, Gaia data and the set of data used in the modelling process. (3 data files)

Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye

Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I = 12 mag, and it was covered in great detail with almost 25 000 data points gathered by a network of telescopes. We present the photometric and spectroscopic follow-up covering 500 days of the event evolution. We employed a full Keplerian binary orbit microlensing model combined with the motion of Earth and Gaia around the Sun to reproduce the complex light curve. The photometric data allowed us to solve the microlensing event entirely and to derive the complete and unique set of orbital parameters of the binary lensing system. We also report on the detection of the first-ever microlensing space-parallax between the Earth and Gaia located at L2. The properties of the binary system were derived from microlensing parameters, and we found that the system is composed of two main-sequence stars with masses 0.57 +/- 0.05 M-circle dot and 0.36 +/- 0.03 M-circle dot at 780 pc, with an orbital period of 2.88 years and an eccentricity of 0.30. We also predict the astrometric microlensing signal for this binary lens as it will be seen by Gaia as well as the radial velocity curve for the binary system. Events such as Gaia16aye indicate the potential for the microlensing method of probing the mass function of dark objects, including black holes, in directions other than that of the Galactic bulge. This case also emphasises the importance of long-term time-domain coordinated observations that can be made with a network of heterogeneous telescopes

Embedded Software of the KM3NeT Central Logic Board

International audienceThe KM3NeT Collaboration is building and operating two deep sea neutrino telescopes at the bottom of the Mediterranean Sea. The telescopes consist of latices of photomultiplier tubes housed in pressure-resistant glass spheres, called digital optical modules and arranged in vertical detection units. The two main scientific goals are the determination of the neutrino mass ordering and the discovery and observation of high-energy neutrino sources in the Universe. Neutrinos are detected via the Cherenkov light, which is induced by charged particles originated in neutrino interactions. The photomultiplier tubes convert the Cherenkov light into electrical signals that are acquired and timestamped by the acquisition electronics. Each optical module houses the acquisition electronics for collecting and timestamping the photomultiplier signals with one nanosecond accuracy. Once finished, the two telescopes will have installed more than six thousand optical acquisition nodes, completing one of the more complex networks in the world in terms of operation and synchronization. The embedded software running in the acquisition nodes has been designed to provide a framework that will operate with different hardware versions and functionalities. The hardware will not be accessible once in operation, which complicates the embedded software architecture. The embedded software provides a set of tools to facilitate remote manageability of the deployed hardware, including safe reconfiguration of the firmware. This paper presents the architecture and the techniques, methods and implementation of the embedded software running in the acquisition nodes of the KM3NeT neutrino telescopes

Embedded Software of the KM3NeT Central Logic Board

International audienceThe KM3NeT Collaboration is building and operating two deep sea neutrino telescopes at the bottom of the Mediterranean Sea. The telescopes consist of latices of photomultiplier tubes housed in pressure-resistant glass spheres, called digital optical modules and arranged in vertical detection units. The two main scientific goals are the determination of the neutrino mass ordering and the discovery and observation of high-energy neutrino sources in the Universe. Neutrinos are detected via the Cherenkov light, which is induced by charged particles originated in neutrino interactions. The photomultiplier tubes convert the Cherenkov light into electrical signals that are acquired and timestamped by the acquisition electronics. Each optical module houses the acquisition electronics for collecting and timestamping the photomultiplier signals with one nanosecond accuracy. Once finished, the two telescopes will have installed more than six thousand optical acquisition nodes, completing one of the more complex networks in the world in terms of operation and synchronization. The embedded software running in the acquisition nodes has been designed to provide a framework that will operate with different hardware versions and functionalities. The hardware will not be accessible once in operation, which complicates the embedded software architecture. The embedded software provides a set of tools to facilitate remote manageability of the deployed hardware, including safe reconfiguration of the firmware. This paper presents the architecture and the techniques, methods and implementation of the embedded software running in the acquisition nodes of the KM3NeT neutrino telescopes