Context
Cities are a challenging habitat for obligate nocturnal mammals because of the ubiquitous use of artificial light at night (ALAN). How nocturnal animals move in an urban landscape, ...particularly in response to ALAN is largely unknown.
Objectives
We studied the movement responses, foraging and commuting, of common noctules (
Nyctalus noctula
) to urban landscape features in general and ALAN in particular.
Methods
We equipped 20 bats with miniaturized GPS loggers in the Berlin metropolitan area and related spatial positions of bats to anthropogenic and natural landscape features and levels of ALAN.
Results
Common noctules foraged close to ALAN only next to bodies of water or well vegetated areas, probably to exploit swarms of insects lured by street lights. In contrast, they avoided illuminated roads, irrespective of vegetation cover nearby. Predictive maps identified most of the metropolitan area as non-favoured by this species because of high levels of impervious surfaces and ALAN. Dark corridors were used by common noctules for commuting and thus likely improved the permeability of the city landscape.
Conclusions
We conclude that the spatial use of common noctules, previously considered to be more tolerant to light than other bats, is largely constrained by ALAN. Our study is the first individual-based GPS tracking study to show sensitive responses of nocturnal wildlife to light pollution. Approaches to protect urban biodiversity need to include ALAN to safeguard the larger network of dark habitats for bats and other nocturnal species in cities.
This article presents a fully integrated low-intermediate frequency (IF) receiver, Dhruva, for global navigation satellite system (GNSS). The compact receiver uniquely features a fully programmable ...IP with no external components and no change in the on- chip hardware for various GNSS signals (civilian and precise positioning). The receiver bandwidth is programmable from 2 to 24 MHz for signals around <inline-formula> <tex-math notation="LaTeX">L1 </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">L2 </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">L5 </tex-math></inline-formula>, and <inline-formula> <tex-math notation="LaTeX">S </tex-math></inline-formula> frequency bands from Navigation with Indian Constellation (NavIC), global positioning system (GPS), Galileo, and BeiDou. A single-to-differential wideband input-matched noise-canceling low-noise amplifier (LNA) is proposed to avoid the external balun and matching components. An on- chip fractional-<inline-formula> <tex-math notation="LaTeX">N </tex-math></inline-formula> phase-locked loop (PLL) with a single voltage-controlled oscillator (VCO) generates the required local oscillator (LO) frequencies. A dc offset correction circuit is proposed in the variable gain amplifier (VGA) to avoid signal saturation. Fabricated in 65-nm CMOS technology, the receiver draws a current of 38.35 mA from a 1.2-V supply while providing a maximum gain of 101.72 dB with a programmable gain of 53.53 dB and a minimum noise figure (NF) of 3.8 dB. The receiver occupies an active die area of 1.96 mm 2 , including the I/O padring with ESD protection.
The number and scale of unmanned aerial vehicles (UAVs) are growing explosively, and the frequent occurrence of UAV intrusions poses a serious threat to national security and social stability. ...Therefore, it has become increasingly important to defend against UAVs and develop related defense technologies. In order to effectively defend against UAVs, it is necessary to interfere with their GPS/Beidou positioning and 2.4G communication technology, thus disrupting their positioning and communication and rendering them unable to function properly. This article designs and implements a continuous wave single tone narrowband interference, and tests its performance, achieving a power suppression effect that seriously interferes with GPS positioning and blocks communication.
Background. Soccer is a collective sport that generates high bioenergetic demands, but at present there is little evidence on the analysis of game intensity in youth soccer players in Chile. ...Objective. To compare the external load according to playing position in young soccer players (U-19) of a professional soccer league team. Methods. Sixteen young Chilean soccer players belonging to a professional team aged between 17 and 19 years (18.2 ± 0.32), who were distributed according to playing position as defenders (n=6), midfielders (n=5) and forwards (n=5), participated in the study. The intensity of play during five games of the final phase of the Chilean first division championship was evaluated with a Catapult® wireless global positioning system (GPS) using a sampling frequency of 10Hz. Results. Differences were found in total distance in the first half between defenders and forwards, between defenders and midfielders with a medium effect size (η²p=0.302), there were also differences in sprinting > 25-30 km/h between defenders and forwards, between defenders and midfielders, and between forwards and midfielders with a small effect size (η²p =0, 225), finally there were differences in high intensity meters between forwards and midfielders, between forwards and defenders with a medium effect size (η²p =0.252), while very high intensity sprinting (> 31km/h) presented differences only between forwards and midfielders with a small effect size (η²p =0. 137). Conclusions. In the present study, differences were found in external loading according to playing position, with forwards presenting higher intensities of play during the match compared to defenders and midfielders. These results provide reference data that can be used for decision making by technical teams for tactical optimization, individualization of training and recovery management in young players.
Antecedentes. El fútbol es un deporte colectivo que genera altas demandas bioenergéticas, pero en la actualidad existe escasa evidencia del análisis de la intensidad de juego en futbolistas jóvenes en Chile. Objetivo. Comparar la carga externa según posición de juego en futbolistas jóvenes (sub-19) de un equipo de la liga profesional de fútbol de Chile. Métodos. Participaron 16 futbolistas jóvenes chilenos pertenecientes a un equipo profesional con edades entre 17 y 19 años (18,2 ± 0,32), que fueron distribuidos según posición de juego en defensas (n=6), volantes (n=5) y delanteros (n=5). Se evalúo la intensidad de juego durante cinco partidos de la fase final del campeonato de primera división de Chile con un sistema de monitoreo de posicionamiento global (GPS) inalámbrico marca Catapult® utilizando una frecuencia de muestreo de 10Hz. Resultados. Se encontraron diferencias en la distancia total en el primer tiempo entre defensas y delanteros, entre defensas y volantes con un tamaño del efecto medio (η²p=0,302), también hubo diferencias en sprint > 25-30 km/h entre defensas y delanteros, entre defensas y volantes, y entre delanteros y volantes con un tamaño del efecto pequeño (η²p =0,225), finalmente hubo diferencias en los metros de alta intensidad entre delanteros y volantes, entre delanteros y defensas con un tamaño del efecto medio (η²p =0,252), mientras que los sprint de muy alta intensidad (> 31km/h) presentaron diferencias solo entre delanteros y volantes con un tamaño del efecto pequeño (η²p =0.137). Conclusiones. En el presente estudio se encontraron diferencias en la carga externa según posición de juego, siendo los delanteros los que presentan mayores intensidades de juego durante el partido en comparación con los defensas y volantes. Estos resultados entregan datos referenciales que pueden ser utilizados para la toma de decisiones por parte de los equipos técnicos para la optimización táctica, individualización del entrenamiento y gestión de la recuperación en futbolistas jóvenes.
The ground-based GPS provides a promising way to assess and calibrate precipitable water vapor (PWV) products from the Moderate-Resolution Imaging Spectrometer (MODIS) which has high spatial ...resolution and near global coverage. This study utilized PWV at about 260 ground-based GPS stations from the Crustal Movement Observation Network of China (CMONOC) from 2015 to 2018 to comprehensively assess the MODIS Near Infrared (NIR) PWV products as well as the latest ECMWF reanalysis, ERA5. Results reveal a general underestimate of MODIS PWV compared to GPS over China, with mean bias of 1.32 mm (GPS-MODIS), compared to −0.28 mm for ERA5 (GPS-ERA5). Taking GPS PWV as references, the average MODIS PWV error root mean square (RMS) is about 5.35 mm, with correlation coefficient (R) of ~90% between GPS and MODIS PWV, compared to the RMS of 1.73 mm and R of ~98% for ERA5. PWV differences between MODIS and GPS also show clear seasonal and climate type dependency over China. A refined linear MODIS PWV calibration model taking into account of climate region difference was then developed and examined. The calibrated MODIS PWV at more than 800 independent GPS stations from China Meteorological Administration (CMA) in the year of 2016 show obvious improvements, with RMS reduced by about 14.7, 17.7, 20.9, 2.5 and 11.3% in tropical monsoon (TM), subtropical monsoon (SM), midlatitude monsoon (MM), humid continental (HC) and plateau (PL) climate region, respectively. Compared to the unified calibration model which does not distinguish the climate regions, the RMS values after calibration using the refined model are reduced by 10.5, 8.3, 9.1, and 11.9% in TM, SM, MM and Plateau climate (PL) region, respectively. In addition, bias values are reduced from 2.01, 3.42, 1.50 and 0.84 mm to 1.64, 0.33, 0.68 and −0.06 mm in TM, SM, MM, PL region, respectively.
•Assessment of MODIS PWV and ERA5 PWV by using PWV at ~260 GPS stations over China from 2015 to 2018.•The temporal and spatial characteristics of MODIS PWV errors depend on season and climate type.•The climate related MODIS PWV calibration model is developed, and the calibration effect of the model is remarkable.
We used the 250‐day postseismic displacements derived from Global Positioning System data to explore various postseismic deformation processes of the 14 April 2010 Mw 6.9 Yushu earthquake, including ...the afterslip of the fault, viscoelastic relaxation in the lower crust and upper mantle, and the poroelastic rebound. The preferred model shows that the afterslip of the fault decays rapidly with time. Viscoelastic relaxation in the lower crust and upper mantle decays slower with time but affects a broader area. Our results show that the range of the steady‐state viscosity in the lower crust is 0.3–2 × $\times $ 1019 Pa s. The optimal steady‐state viscosity in the lower crust is ∼5 × $\times $ 1018 Pa s. We simulate the deformation due to the poroelastic rebound in the top 10 km upper crust. Model results indicate that the poroelastic rebound only produces a few millimeters surface deformation and may be a secondary‐order postseismic process.
Plain Language Summary
In 2010, the Mw 6.9 Yushu earthquake occurred on the Yushu fault in the eastern Tibetan Plateau. Global Positioning System (GPS) measurements in the first 250 days after the 2010 event show that short‐term postseismic displacements featured mainly a left‐lateral motion across the fault. Model results show that the afterslip of the fault controls mainly the deformation in the near‐field area. The rheological structure in the lower crust in this region has no obvious heterogeneity. Our model provides further constraints on the rheological structures in the lower crust and upper mantle beneath the eastern Tibetan Plateau.
Key Points
Afterslip of the fault and viscoelastic relaxation in the lower crust together control the short‐term postseismic deformation
Afterslip takes place mostly within 10 years after the earthquake and decays rapidly with time
The steady‐state viscosity in the lower crust is 0.3–2 × 1019 Pa s with an optimal value ∼5 × 1018 Pa s
"Best tracks" are National Hurricane Center (NHC) poststorm analyses of the intensity, central pressure, position, and size of Atlantic and eastern North Pacific basin tropical and subtropical ...cyclones. This paper estimates the uncertainty (average error) for Atlantic basin best track parameters through a survey of the NHC Hurricane Specialists who maintain and update the Atlantic hurricane database. A comparison is then made with a survey conducted over a decade ago to qualitatively assess changes in the uncertainties. Finally, the implications of the uncertainty estimates for NHC analysis and forecast products as well as for the prediction goals of the Hurricane Forecast Improvement Program are discussed.
Abstract
Projects focused on movement behaviour and home range are commonplace, but beyond a focus on choosing appropriate research questions, there are no clear guidelines for such studies. Without ...these guidelines, designing an animal tracking study to produce reliable estimates of space‐use and movement properties (necessary to answer basic movement ecology questions), is often done in an ad hoc manner.
We developed ‘
movedesign
’, a user‐friendly Shiny application, which can be utilized to investigate the precision of three estimates regularly reported in movement and spatial ecology studies: home range area, speed and distance travelled. Conceptually similar to statistical power analysis, this application enables users to assess the degree of estimate precision that may be achieved with a given sampling design; that is, the choices regarding data resolution (sampling interval) and battery life (sampling duration).
Leveraging the ‘
ctmm
’
R
package, we utilize two methods proven to handle many common biases in animal movement datasets: autocorrelated kernel density estimators (AKDEs) and continuous‐time speed and distance (CTSD) estimators. Longer sampling durations are required to reliably estimate home range areas via the detection of a sufficient number of home range crossings. In contrast, speed and distance estimation requires a sampling interval short enough to ensure that a statistically significant signature of the animal's velocity remains in the data.
This application addresses key challenges faced by researchers when designing tracking studies, including the trade‐off between long battery life and high resolution of GPS locations collected by the devices, which may result in a compromise between reliably estimating home range or speed and distance. ‘
movedesign
’ has broad applications for researchers and decision‐makers, supporting them to focus efforts and resources in achieving the optimal sampling design strategy for their research questions, prioritizing the correct deployment decisions for insightful and reliable outputs, while understanding the trade‐off associated with these choices.
Driver assistant systems have approved their essential role in increasing safety in the driving environment. One of their main features is the ability to provide information about location of the ...vehicle so that the driver can understand how and where to go. Moreover, automatically report the emergency in case of accidents to accelerate the rescue process. Unfortunately, poor Internet connection in many places and the inaccurate GPS information on traveling roads, in particular, make the localization process even harder. In this paper, we propose an offline localization system that can estimate the location of the vehicle in real-time using edge devices. Our proposed system consists of three main components; the first component is the image matching part to estimate the rotation and transition between two images; the second component is the dynamic objects (vehicles, pedestrians, and etc.) segmentation to filter out the matches from them; and finally, an image retrieval system to auto-correct the location using predefined coordinates of famous landmarks.
