Stand-alone Tracking Research Articles

Expected performance of the High Energy Particle Detector (HEPD-02) tracking system on board of the second China Seismo-Electromagnetic Satellite

The China Seismo-Electromagnetic Satellite (CSES) is a scientific space program that aims to deepen the comprehension of the time correlation between the main earthquake shocks and an increase in the electron flux in the inner Van Allen belt. For this purpose, the suite of payloads on board the second CSES satellite (CSES-02) consists of several detectors. The launch of CSES-02 is foreseen in 2024. The present work is focused on the second generation High-Energy Particle Detector (HEPD-02), developed by Limadou Italian collaboration, and in particular on its tracking system (Direction Detector — DD) to reconstruct the incident particle angle. The DD is made of five standalone tracking modules, consisting, as first and unique case, of monolithic silicon pixel sensors (MAPS), namely ALTAI. This chip was developed in the framework of the ALICE (A Large Ion Collider Experiment) ITS sensor studies. The results on the DD performance are discussed based on the demanding requirements of space applications.

Deeply-Coupled GNSS Dual-Band Collaborative Tracking Using the Extended Strobe Correlator

Continuous and precise code delay tracking is essential in challenging environments such as urban canyons where multipath and frequent signal blockage may lead to performance degradation and loss of lock of signals. The strobe correlator (SC) is an effective technique for baseband multipath mitigation and is commonly used for GNSS signal tracking enhancement. An SC has two pairs of early and late correlators, one with a wide and another with a narrow correlator spacing. This paper extends the conventional SC design by applying its correlator pairs on dual-band GNSS signals to realize an extended strobe correlator (ESC). An ESC takes advantage of the natural distinct bandwidth of narrow-band and wide-band signals, e.g., L1 C/A and L5Q signals, to form a dual-band combination at the correlator level in a deeply-coupled manner. Narrow-band L1 signal tracking ensures robustness, while the wide-band L5 signal improves the tracking precision. A moving average window filters the L1 measurement to prevent the noise impact on L5 tracking, providing necessary inter-band assistance to resolve challenges such as code delay misalignment and precision mismatch. Through both Monte Carlo simulation and real data collected in urban environments, this work demonstrates that an ESC can achieve improved overall robustness against loss-of-lock and multipath mitigation performance over standalone tracking. Compared with KF-based combined (KFC-based) tracking, ESC has higher tracking precision under weak signal environment and robustness during signal blockage, but larger residual multipath error.

Extracting Mural and Volumetric Growth Patterns of Platelet Aggregates on Engineered Surfaces by Use of an Entity Tracking Algorithm.

Thrombosis is a major complication that can occur in both blood-contacting devices and regions and in regions of vascular damage. Microfluidic devices are popular templates to model various thrombogenic settings and to assess conditions that lead to bulk channel occlusion. However, area-averaged measurements miss the opportunity to extract real-time information on thrombus evolution and early dynamics of thrombus formation and propagation, which result in late-stage bulk channel occlusion. To clarify these dynamics, we have developed a standalone tracking algorithm that uses consecutive image connectivity and minimal centroid distance mappings to uniquely index all appearing thrombi in fluorescence time-lapse videos http://links.lww.com/ASAIO/A887 , and http://links.lww.com/ASAIO/A888 . This leads to measurements of all individual aggregates that can in turn be studied as ensembles. We applied tracking to fluorescence time-lapse videos http://links.lww.com/ASAIO/A887 , and http://links.lww.com/ASAIO/A888 of thrombosis across both collagen-functionalized substrate and across the surface of a roughened titanium alloy (Ti6Al4V) at a shear rate of 4000 s -1 . When comparing ensemble-averaged measurements to area-averaged metrics, we unveil immediate, steady thrombus growth at early phases on collagen surfaces and unstable thrombus attachment to roughened Ti6Al4V surfaces on Ti6Al4V surfaces. Additionally, we introduce tracked thrombus eccentricity and fluorescence intensity as additional volumetric measures of thrombus growth that relate back to the primary thrombosis mechanism at play. This work advocates for the complementation of surface macrostate metrics with characteristic thrombus microstate growth patterns to accurately predict critical thrombosis events.

The silicon vertex detector of the Belle II experiment

In 2019 the Belle II experiment started data taking at the asymmetric SuperKEKB collider (KEK, Japan) operating at the Y(4S) resonance. Belle II will search for new physics beyond the standard model by collecting an integrated luminosity of 50 ab−1. The silicon vertex detector (SVD), consisting of four layers of double-sided silicon strip sensors, is one of the two vertex sub-detectors. The SVD extrapolates the tracks to the inner pixel detector (PXD) with enough precision to correctly identify hits in the PXD belonging to the track. In addition the SVD has standalone tracking capability and utilizes ionization to enhance particle identification in the low momentum region. The SVD is operating reliably and with high efficiency, despite exposure to the harsh beam background of the highest peak-luminosity collider ever built. High signal-to-noise ratio and hit efficiency have been measured, as well as the spatial resolution; all these quantities show excellent stability over time. Data-simulation agreement on cluster properties has recently been improved through a careful tuning of the simulation. The precise hit-time resolution can be exploited to reject out-of-time hits induced by beam background, which will make the SVD more robust against higher levels of background. During the first three years of running, radiation damage effects on strip noise, sensor currents and depletion voltage have been observed, as well as some coupling capacitor failure due to intense radiation bursts. None of these effects cause significant degradation in the detector performance.

Online Reconstruction and Calibration with Feedback Loop in the ALICE High Level Trigger

ALICE (A Large Heavy Ion Experiment) is one of the four large scale experiments at the Large Hadron Collider (LHC) at CERN. The High Level Trigger (HLT) is an online computing farm, which reconstructs events recorded by the ALICE detector in real-time. The most compute-intense task is the reconstruction of the particle trajectories. The main tracking devices in ALICE are the Time Projection Chamber (TPC) and the Inner Tracking System (ITS). The HLT uses a fast GPU-accelerated algorithm for the TPC tracking based on the Cellular Automaton principle and the Kalman filter. ALICE employs gaseous subdetectors which are sensitive to environmental conditions such as ambient pressure and temperature and the TPC is one of these. A precise reconstruction of particle trajectories requires the calibration of these detectors. As first topic, we present some recent optimizations to our GPU-based TPC tracking using the new GPU models we employ for the ongoing and upcoming data taking period at LHC. We also show our new approach for fast ITS standalone tracking. As second topic, we present improvements to the HLT for facilitating online reconstruction including a new flat data model and a new data flow chain. The calibration output is fed back to the reconstruction components of the HLT via a feedback loop. We conclude with an analysis of a first online calibration test under real conditions during the Pb-Pb run in November 2015, which was based on these new features.

Optimization of Rao-Blackwellized Particle Filter in Activity Pedestrian Simultaneously Localization and Mapping (SLAM): An Initial Proposal

When Global Positioning Systems are obstructed, standalone pedestrian tracking can be very daunting. Users in such obstructed environments (especially in home environments) will find it difficult to perform on-site navigation. It is important to create a standalone pedestrian tracking system that provides better location determination services with less computational complexity and deployment cost. One promising way to implement this service is through the use of Inertial Measurement Unit (IMU) sensors. This tracking method provides the pinpointing of standalone tracking information but is handicapped by missing stance phase during pedestrian walking activities. A new pedestrian stance detection using simultaneously localization and mapping (SLAM) will be designed in this paper with a focus on robust indoor positioning systems. We will present our preliminary results to illustrate the performance of the system for an indoor environment set-up at the end of this paper.

Near future upgrades of the CMS pixel detector

The silicon pixel detector is the innermost component of the CMS tracking system, providing high precision space point measurements of charged particle trajectories. The current pixel detector is designed to operate at a maximum luminosity of 1×1034 cm−2 s−1. Before 2018 the instantaneous luminosity of the LHC is expected to reach 2×1034 cm−2 s−1, which will significantly increase the number of interactions per bunch crossing. The performance of the current pixel detector in such high occupancy environment will be degraded due to substantial data-loss and effects of radiation damage of sensors, built up over the operational period. In order to maintain or exceed its current performance, the CMS pixel detector will be replaced by a new lightweight system with additional detection layers, better acceptance and improved readout electronics. The upgraded pixel detector will provide improved track and vertex reconstruction, standalone tracking capabilities, as well as identification of particles with longer lifetimes, which will be crucial elements of many physics analyses.

Performance of the upgraded CMS pixel detector for the LHC Phase 1

After the Phase 1 upgrade the Large Hadron Collider is expected to reach an instantaneous luminosity of 2 × 1034cm−2s−1 or higher, resulting in an extreme operating environment for the experiments, particularly their central tracking devices. In order to maintain its current performance level, the CMS pixel detector will be replaced by a more lightweight system with additional instrumentation, better acceptance and refined front-end electronics. The upgraded pixel detector will provide improved track and vertex reconstruction, standalone tracking capabilities, as well as identification of particles with pico-second lifetimes, which will be key elements of many physics analyses with CMS.

Hospital Wireless Local Area Network-Based Tracking System

ObjectivesThe purpose of this study was to develop a prototype wireless local area network (LAN)-based tracking system and evaluate its efficacy.MethodsA wireless LAN-based tracking system was developed with a personal digital assistant (PDA) having a simple text messaging function and a prototype stand-alone tracking device. Evaluation of the effectiveness of the tracking system was performed in two ways. Twenty-five messages were sent to nurses by direct communication and 46 messages were sent by the wireless system. Thirty cases by nurses and 30 cases by the wireless system to locate hospital equipment were performed. The time required to transfer messages and to locate equipment was measured and analyzed with a Mann-Whitney test and a paired t-test, respectively.ResultsThe mean time required to transfer messages by direct communication and by the wireless system were 37.92 ± 19.19 seconds and 30.65 ± 9.80 seconds, respectively which were not statistically different (p = 0.108). The mean time required to locate equipment by the nurses and by the wireless system was 234.00 ± 59.99 and 23.97 ± 6.17 seconds, respectively which was statistically different (p < 0.001).ConclusionsThe wireless LAN-based tracking system can save time for nurses to communicate and to check for the location of equipment in wards which allows nurses to spend more time and attention to patient care and safety.

Tracking and vertexing capabilities of the CMS tracking detector with the first LHC data

Abstract The CMS experiment relies on a tracking detector entirely based on silicon sensors for the reconstruction of charged particles in the hostile radiation environment of proton–proton collisions at the CERN LHC. From the recent data collected by CMS at a center-of-mass energy of 7 TeV, the tracking, vertexing and b-jet identification performance have been measured. These measurements include the muon tracking efficiency, track transverse momentum resolution, track impact parameter resolution, primary vertex efficiency and resolution, and b-jet identification efficiency. The tracking performance relies, in particular, on the excellent pixel detector tracking capabilities, which are exploited in many contexts such as seeding, b-jet identification, and beam-spot monitor. The pixel stand-alone tracking and vertexing capabilities are shown for a particular application: the beam-spot monitor.

Laser-based standalone tracking system

A laser-based standalone tracking system is presented. To transform a laser beam into a structured pattern, a diffractive optical element was used. By analysing the projected pattern shape, the co-ordinate transform between the laser and its projection was computed in real-time. Computed transform was used for virtual object overlays in Augmented Reality.

Study of the Capabilities of the ALICE Inner Tracking System Stand-Alone for HBT Analysis

Results are shown from a Monte Carlo simulation study of the capabilities of the Inner Tracking System of the ALICE experiment, used in standalone mode, for HBT analysis of Pb−Pb collisions at LHC energies (5.5 ATeV). Different values of the coherence factor and the Gaussian source radius have been studied. For this purpose, a specific ITS stand-alone tracking algorithm, based on the Denby-Peterson neural algorithm, has been developed.

The SLD VXD3 detector and its initial performance

The SLD collaboration completed construction of a new CCD vertex detector (VXD3) in January 1996 and started data taking in April 1996 with the new system. VXD3 is an upgrade of the original CCD vertex detector, VXD2, which had successfully operated in SLD for three years. VXD3 consists of 96 large area CCDs, each having 3.2 million 20 μm × 20 μm pixels. By reducing the detector material and lengthening the lever arm, VXD3 is expected to improve secondary vertex resolution by about a factor of two compared with VXD2. The new three-layered structure enables stand-alone tracking without any ambiguity and its extended size along the beam direction improves the polar-angle coverage to |cos θ| < 0.85. An overview of this detector system and its initial performance are described.

Performance Characteristics of 350 kW Photovoltaic Power System for Saudi Arabian Villages

The performance characteristics of the Saudi Solar Village Project, one of several projects sponsored by the Saudi Arabian-United States Program for Cooperation in the Field of Solar Energy (SOLERAS), a five-year jointly-funded $100M program, are presented in this paper. It is original and far reaching with respect to the scope and variety of solar technologies involved as well as the unique joint and cooperative manner in which the technology involved is developed and transferred. One of the program's objectives is to enhance the quality of life in rural areas within traditional ways of life. The Saudi Solar Village Project thus seeks to determine the feasibility of utilizing solar power to generate electricity in remote areas not served by existing electric power grid facilities. Details of the design of the 350 kW photovoltaic power system and its various subsystems are presented and the performance of the system and subsystems during initial acceptance testing of the system are discussed in this paper. The system, which to date has performed very well and in accordance with design specification, has combined both standard hardware and state-of-the-art concentrator photovoltaic subsystems, to yield the largest stand-alone tracking concentrator photovoltaic system in the world.