scholarly journals Methodology to estimate ionospheric scintillation risk maps and their contribution to position dilution of precision on the ground

2020 ◽  
Vol 94 (2) ◽  
Author(s):  
Alexandra Koulouri ◽  
Nathan D. Smith ◽  
Bruno C. Vani ◽  
Ville Rimpiläinen ◽  
Ivan Astin ◽  
...  
Keyword(s):  
Ionospheric Scintillation ◽  
Navigation Systems ◽  
End User ◽  
Equatorial Anomaly ◽  
Dilution Of Precision ◽  
Global Positioning ◽  
Risk Maps ◽  
The Given ◽  
Satellite Receiver

Abstract Satellite-based communications, navigation systems and many scientific instruments rely on observations of trans-ionospheric signals. The quality of these signals can be deteriorated by ionospheric scintillation which can have detrimental effects on the mentioned applications. Therefore, monitoring of ionospheric scintillation and quantifying its effect on the ground are of significant interest. In this work, we develop a methodology which estimates the scintillation-induced ionospheric uncertainties in the sky and translates their impact to the end users on the ground. First, by using the risk concept from decision theory and by exploiting the intensity and duration of scintillation events (as measured by the $$S_4$$ S 4 index), we estimate ionospheric risk maps that could readily give an initial impression on the effects of scintillation on the satellite-receiver communication. However, to better understand the influence of scintillation on the positioning accuracy on the ground, we formulate a new weighted dilution of precision (WPDOP) measure that incorporates the ionospheric scintillation risks as weighting factors for the given satellite-receiver constellations. These weights depend implicitly on scintillation intensity and duration thresholds which can be specified by the end user based on the sensitivity of the application, for example. We demonstrate our methodology by using scintillation data from South America and produce ionospheric risk maps which illustrate broad scintillation activity, especially at the equatorial anomaly. Moreover, we construct ground maps of WPDOP over a grid of hypothetical receivers which reveal that ionospheric scintillation can also affect such regions of the continent that are not exactly under the observed ionospheric scintillation structures. Particularly, this is evident in cases when only the global positioning system is available.

scholarly journals Correction to: Methodology to estimate ionospheric scintillation risk maps and their contribution to position dilution of precision on the ground

2020 ◽  
Vol 94 (3) ◽  
Author(s):  
Alexandra Koulouri ◽  
Nathan D. Smith ◽  
Bruno C. Vani ◽  
Ville Rimpiläinen ◽  
Ivan Astin ◽  
...  
Keyword(s):  
Ionospheric Scintillation ◽  
Dilution Of Precision ◽  
Risk Maps

scholarly journals Altitude on Cartographic Materials and Its Correction According to New Measurement Techniques

2021 ◽  
Vol 13 (3) ◽  
pp. 444
Author(s):  
Kamil Maciuk ◽  
Michał Apollo ◽  
Joanna Mostowska ◽  
Tomáš Lepeška ◽  
Mojca Poklar ◽  
...  
Keyword(s):  
Measurement Techniques ◽  
Satellite System ◽  
Navigation Systems ◽  
Direct Measurements ◽  
Global Positioning ◽  
The Subject ◽  
Printed Materials ◽  
Global Navigation Satellite ◽  
Modern Technologies

Determining the correct height of mountain peaks is vital for tourism, but it is also important as a reference point for devices equipped with GPS (Global Positioning System), e.g., watches or car navigation systems. The peak altitude data are part of geographic and geodetic information. As more modern technologies and equipment become available, their precisions should increase. However, verification of peak heights is usually only conducted for the highest, well-known mountains—lower peaks or mountain passes are rarely verified. Therefore, this study focuses on an investigation of 12 altitude points on a section of the longest and most famous touristic trail in Poland (the Main Beskid Trail), located in the Orava–Żywiec Beskids Mts (Mountains). The aim of this research is to measure and verify the heights of the 12 selected mountain peaks, in addition to evaluating the chosen methods based on the quality of the obtained data and determining their suitability and opportunities for use in further research. Measurements were obtained at the most specific height points—on the 12 highest points of the summits. This study compares two modern measurement techniques: the global navigation satellite system (GNSS) and light detection and ranging (LiDAR). The obtained results were later compared with those widely used on the internet and in printed materials (period covered: 1884–2015). This analysis demonstrates that lesser-known objects are rarely the subject of remeasurement and significant altitude errors may occur, primarily because the heights originated from a source in the past when modern methods were not available. Our findings indicate that the heights of the peaks presented in cartographic materials are inaccurate. The assumed heights should be corrected by direct measurements using modern techniques.

Efficient DOP Calculation for GPS with and without Altimeter Aiding

2001 ◽  
Vol 54 (2) ◽  
pp. 269-279 ◽  
Author(s):  
Dah-Jing Jwo
Keyword(s):  
Closed Form ◽  
Dilution Of Precision ◽  
Gps Satellites ◽  
Optimum Selection ◽  
Global Positioning ◽  
Geometric Dilution Of Precision ◽  
Conventional Solution ◽  
Volume Method ◽  
The Relationship

Geometric Dilution Of Precision (GDOP) is a factor that describes the effect of geometry on the relationship between measurement error and position determination error. It is used to provide an indication of the quality of the solution. Conventional closed-form GDOP calculation formula applied to all possible combinations of visible satellites is rather time consuming, especially as the number of satellites grows. Approximations, such as the maximum volume method, are faster but optimum selection is not guaranteed. In this paper, a more concise but efficient solution for the calculation of GDOP value in the case of four Global Positioning System (GPS) satellites is firstly reviewed and then extended to cover the other forms of dilution of precision (DOP) values, including vertical DOP (VDOP) and horizontal DOP (HDOP). Secondly, a review and extension of the conventional solution is performed in the case of three GPS satellites aided by an altimeter. Based on the ideas gained from these two approaches, a simpler closed-form DOP formula for three GPS satellites aided by an altimeter is derived. The advantage of the proposed formulation is that it is simpler and thus reduces the computational load in comparison to the conventional one.

Professional dilemmas for caregivers in Turkish home care settings in Germany

2014 ◽  
Vol 1 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Jan Basche
Keyword(s):  
Healthcare Services ◽  
Insurance Companies ◽  
Or Education ◽  
Migrant Communities ◽  
Caregiver Relationship ◽  
International Nursing ◽  
Nursing Literature ◽  
Intercultural Care ◽  
The Given

While calling for culturally sensitive healthcare services in migrant communities, the international nursing literature on intercultural care predominantly describes nursing staff as lacking cultural competences and immigrant customers as lacking cleverness to navigate the labyrinths of national healthcare systems. Congruences in language, culture and religion in the customer-caregiver relationship can decisively improve the quality of care. However, they do not automatically guarantee smooth working processes in monocultural in-home settings. On the contrary, new problems occur here for Turkish caregivers which are unknown to the legions of native professionals who feel challenged by migrants and which go beyond differences such as age, sex, income or education. While no cultural or religious brokering is necessary between customers and personnel in the given context in Germany, new challenges arise when caregivers are expected to legally broker between customers and insurance companies or doctors. Conflicting expectations of customers and management as well as their own colliding social and professional roles put the caregivers in a quandary and must be competently managed.

MODIFIKASI MODEL PEMBELAJARAN TEAM ASSISTED INDIVIDUALIZATION DENGAN STRATEGI PEMBELAJARAN TUGAS DAN PAKSA

2019 ◽  
Vol 2 ◽  
Author(s):  
Lea Christy Restu Kinasih ◽  
Dewi Fatimah ◽  
Veranica Julianti
Keyword(s):  
Cooperative Learning ◽  
Learning Strategies ◽  
Learning Process ◽  
Learning Model ◽  
Learning Models ◽  
Classroom Learning ◽  
Quality Of Learning ◽  
The Given

The selection and determination of appropriate learning strategies can improve the results to be obtained from the application of classroom learning models. This writing aims to discipline students to develop individual abilities of students to be more active in the learning process and improve the quality of learning. The learning process in Indonesia in general only uses conventional learning models that make students passive and undeveloped. In order for the quality of learning to increase, the Team Assisted Individualization learning model is combined with the task learning and forced strategies. The Team Assisted Individualization cooperative learning model is one of the cooperative learning models that combines learning individually and in groups. Meanwhile, task and forced learning strategies are strategies that focus on giving assignments that require students to complete them on time so that the learning process can run effectively. Students are required to do assignments according to the given deadline. This makes students become familiar with the tasks given by the teacher. Combining or modifying the learning model of the assisted individualization team with forced and forced learning strategies is expected to be able to make students more active, disciplined, independent, creative in learning and responsible for the tasks assigned. Therefore this method of incorporation is very necessary in the learning process and can be applied to improve the quality of learning in schools.

Integrating Safety-II into Safety Management

2021 ◽  
Author(s):  
Toni Wäfler ◽  
Rahel Gugerli ◽  
Giulio Nisoli
Keyword(s):  
Risk Factor ◽  
Safety Factor ◽  
Safety Management ◽  
Management Systems ◽  
Safety Management Systems ◽  
Safety Science ◽  
Human Failure ◽  
The Given ◽  
Freedom Of Action

We all aim for safe processes. However, providing safety is a complex endeavour. What is it that makes a process safe? And what is the contribution of humans? It is very common to consider humans a risk factor prone to errors. Therefore, we implement sophisticated safety management systems (SMS) in order to prevent potential "human failure". These SMS provide an impressive increase of safety. In safety science this approach is labelled "Safety-I", and it starts to be questioned because humans do not show failures only. On the contrary, they often actively contribute to safety, sometimes even by deviating from a procedure. This "Safety-II" perspective considers humans to be a "safety factor" as well because of their ability to adjust behaviour to the given situation. However, adaptability requires scope of action and this is where Safety-I and Safety-II contradict each other. While the former restricts freedom of action, the latter requires room for manoeuvring. Thus, the task of integrating the Safety-II perspective into SMS, which are traditionally Safety-I based, is difficult. This challenge was the main objective of our project. We discovered two methods that contribute to the quality of SMS by integrating Safety-II into SMS without jeopardizing the Safety-I approach.

The influence of unintentional radio interference on the equipment operation quality of satellite radio navigation systems consumers

2020 ◽  
pp. 165-170
Keyword(s):  
Underlying Surface ◽  
Navigation Systems ◽  
Signal Attenuation ◽  
Radio Navigation ◽  
Equipment Operation ◽  
Atmospheric Noise ◽  
Detection Mode ◽  
Signal Mode ◽  
Cosmic Noise

The analysis an influence of reflections from the underlying surface, atmospheric noise, the Earth’s surface, cosmic noise and signal attenuation of the signal the atmosphere, as well as the flight dynamics of the aircraft (AC) on the signal/noise ratio and, accordingly, on the accuracy of AC navigation definitions by using consumer equipment of the satellite radio navigation systems. The analysis an influence of reflections from the underlying surface on the equipment operation quality of the satellite radio navigation systems consumers is carried out by using the Beckman model, in accordance with the earth’s surface appears to consist of flat faces with an arbitrary slope. It is noted that reflections from the underlying surface have a greater effect on the quality of functioning of the consumer equipment of the satellite radio navigation systems in the tracking signal mode than in the detection mode. In this case, the influence of reflections increases with decreasing flight altitude and an increase in the angle of heel of the AC in the direction of the navigation spacecraft.

О ТОЧНОСТИ ОПРЕДЕЛЕНИЯ КООРДИНАТ ПОДВОДНОГО МОДУЛЯ НА ОСНОВЕ ИЗМЕРЕННЫХ ПАРАМЕТРОВ ДВИЖЕНИЯ БУКСИРУЕМОЙ СИСТЕМЫ

2020 ◽  
Author(s):  
V.V. Kostenko ◽  
Yu.V. Vaulin ◽  
F.S. Dubrovin ◽  
O.Yu. Lvov
Keyword(s):  
Immersion Depth ◽  
Computational Algorithms ◽  
Navigation Systems ◽  
Short Baseline ◽  
Positioning Accuracy ◽  
Underwater Acoustic ◽  
Ground Speed ◽  
Cable Length ◽  
Acoustic Navigation

Буксируемый подводный модуль (БПМ) эффективно используется для решения задач, связанных с координированием подводных объектов, местоположение которых подлежит уточнению в процессе их детальногообследования. При этом большое значение имеет точность определения координат самого буксируемогомодуля относительно судна-буксировщика. Использование гидроакустических навигационных средств, вчастности систем с ультракороткой базой (ГАНС УКБ), ограничено вследствие помех, влияющих на качествосигналов в приемной антенне. Альтернативой служит метод определения координат БПМ на основе данныхтраекторных измерений параметров буксируемой системы. К числу последних относятся расчетные значенияпараметров кабеля связи в установившихся режимах буксировки, значения путевой скорости и путевого углабуксировщика, а также измеренные значения длины кабеля, глубины погружения и курса БПМ. В работе дансравнительный анализ различных вариантов вычислительных алгоритмов, позволяющих получить оценки точности определения координат БПМ в различных режимах стационарной буксировки и при наличии сбоев вработе навигационных средств.The towed underwater module (TUM) is a useful toolfor solving problems of the positioning of the underwaterobjects, the location of which must be clarified during its detailedinspection. Herewith, the accuracy of the determinationof the coordinates of the towed module itself relative tothe towing vessel is essential for such kind of problems. Theuse of underwater acoustic navigation means, the systemswith ultra-short baseline (USBL) in particular, are limiteddue to interference affecting the quality of the signals on thereceiving antenna. As an alternative, the method is proposedfor TUM positioning based on trajectory measurements ofparameters of the towed system, which may include calculatedvalues of communication cable parameters in steadystatetowing modes, values of ground speed and towing angle,as well as measured cable length, immersion depth, andTUM heading. The paper provides a comparative analysisof various versions of computational algorithms, which allowobtaining estimates of the TUM positioning accuracy indifferent modes of stationary towing and in the presence offailures in navigation systems operation.

scholarly journals Identification of the State of Electrical Appliances with the Use of a Pulse Signal Generator

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 673
Author(s):  
Augustyn Wójcik ◽  
Piotr Bilski ◽  
Robert Łukaszewski ◽  
Krzysztof Dowalla ◽  
Ryszard Kowalik
Keyword(s):  
Measurement System ◽  
Cross Correlation ◽  
Pulse Signal ◽  
Signal Generator ◽  
Experimental Results ◽  
The Novel ◽  
End User ◽  
Standard Classification ◽  
Electrical Appliance

The paper presents the novel HF-GEN method for determining the characteristics of Electrical Appliance (EA) operating in the end-user environment. The method includes a measurement system that uses a pulse signal generator to improve the quality of EA identification. Its structure and the principles of operation are presented. A method for determining the characteristics of the current signals’ transients using the cross-correlation is described. Its result is the appliance signature with a set of features characterizing its state of operation. The quality of the obtained signature is evaluated in the standard classification task with the aim of identifying the particular appliance’s state based on the analysis of features by three independent algorithms. Experimental results for 15 EAs categories show the usefulness of the proposed approach.

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