This paper introduces a design and implementation of a base station, capable of positioning sensor nodes using an optical scheme. The base station consists of a pulse laser module, optical detectors and beam splitter, which are mounted on a rotation-stage, and a Time to Digital Converter (TDC). The optical pulse signal transmitted to the sensor node with a Corner Cube Retro-reflector (CCR) is reflected to the base station, and the Time of Flight (ToF) data can be obtained from the two detectors. With the angle and flight time data, the position of the sensor node can be calculated. The performance of the system is evaluated by using a commercial CCR. The sensor nodes are placed at different angles from the base station and scanned using the laser. We analyze the node position error caused by the rotation and propose error compensation methods, namely the outlier sample exception and decreasing the confidence factor steadily using the recursive least square (RLS) methods. Based on the commercial CCR results, the MEMS CCR is also tested to demonstrate the compatibility between the base station and the proposed methods. The result shows that the localization performance of the system can be enhanced with the proposed compensation method using the MEMS CCR.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4063014 | PMC |
http://dx.doi.org/10.3390/s140508313 | DOI Listing |
Sci Rep
January 2025
School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang, 050043, China.
Hydrological forecasting is of great significance to regional water resources management and reservoir operation. Climate change has increased the complexity and difficulty of hydrological forecasting. In this study, a hybrid explainable streamflow forecasting model based on CNN-LSTM-Attention was established for five typical river source regions in the eastern Qinghai-Tibet Plateau (EQTP).
View Article and Find Full Text PDFFront Insect Sci
December 2024
Millennium Institute Biodiversity of Antarctic and Sub-Antarctic Ecosystems (BASE), Santiago, Chile.
Despite increasing awareness of the threats they pose, exotic species continue to arrive in Antarctica with anthropogenic assistance, some of which inevitably have the potential to become aggressively invasive. Here, we provide the first report of the globally cosmopolitan species (Diptera, Psychodidae; commonly known as moth flies) in Antarctica during the austral summer of 2021/2022, with the identification confirmed using traditional taxonomic and molecular approaches. The species was present in very large numbers and, although predominantly associated with the drainage and wastewater systems of Antarctic national operator stations in synanthropic situations, it was also present in surrounding natural habitats.
View Article and Find Full Text PDFPLoS One
December 2024
São Paulo State University (Unesp), School of Sciences and Engineering, Tupã, São Paulo, Brasil.
Meteorological data acquired with precision, quality, and reliability are crucial in various agronomy fields, especially in studies related to reference evapotranspiration (ETo). ETo plays a fundamental role in the hydrological cycle, irrigation system planning and management, water demand modeling, water stress monitoring, water balance estimation, as well as in hydrological and environmental studies. However, temporal records often encounter issues such as missing measurements.
View Article and Find Full Text PDFSci Rep
December 2024
School of Civil Engineering, Chongqing Three Gorges University, Chongqing, 404100, China.
Runoff fluctuations under the influence of climate change and human activities present a significant challenge and valuable application in constructing high-accuracy runoff prediction models. This study aims to address this challenge by taking the Wanzhou station in the Three Gorges Reservoir area as a case study to optimize various prediction models. The study first selects artificial neural network (ANN) and support vector machine (SVM) as the base models.
View Article and Find Full Text PDFSports Med
December 2024
Ultra Sports Science Foundation, Pierre-Bénite, France.
Background: Antarctic expeditions, although supported by scientific knowledge, face various challenges, with little research conducted to explore the physical demands that explorers experience.
Objective: To summarise physiological, psychological, body composition and nutritional changes faced during trek expeditions in the Antarctic's continental portion.
Design: Systematic review.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!