scholarly journals Riverbed Mapping with the Usage of Deterministic and Geo-Statistical Interpolation Methods: The Odra River Case Study

2021 ◽  
Vol 13 (21) ◽  
pp. 4236
Author(s):  
Anna Uciechowska-Grakowicz ◽  
Oscar Herrera-Granados
Keyword(s):  
Interpolation Method ◽  
Absolute Error ◽  
Satellite System ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Interpolation Methods ◽  
River Bed ◽  
Odra River ◽  
Global Navigation Satellite

In this contribution, interpolation methods were assessed to build the bathymetry of 200 km of the Odra River in South Poland. The River Bed Mapping (RBM) was carried out surveying the depth of several reaches of the canalized part of the river using an Global Navigation Satellite System (GNSS) with an echo sounder as well as two navigation schemes. The values from the interpolation were compared with the data from a classical cross-sectional survey as part of the ISOK (Polish acronym for Information System of Country Protection Against Extraordinary Hazards) project. Two statistical errors between the interpolation values and the ISOK information were estimated, namely, the Mean Absolute Error (MAE) and the Root Mean Square Error (RMSE). Thanks to the presented analysis, it was possible to compare and analyze which interpolation method fits the best for the batymetric surveying of a shallow river. For this specific case study, the TIN (Triangular Irregular Network) and the NN (Natural Neighbor) methods generates the most accurate RBM.

scholarly journals Inventory of Locations of Old Mining Works Using LiDAR Data: A Case Study in Slovakia

2021 ◽  
Vol 13 (12) ◽  
pp. 6981
Author(s):  
Marcela Bindzarova Gergelova ◽  
Slavomir Labant ◽  
Jozef Mizak ◽  
Pavel Sustek ◽  
Lubomir Leicher
Keyword(s):  
Satellite System ◽  
Precise Determination ◽  
Lidar Data ◽  
Positional Accuracy ◽  
Current Form ◽  
Mining History ◽  
Mining Works ◽  
Gnss Measurements ◽  
Global Navigation Satellite

The concept of further sustainable development in the area of administration of the register of old mining works and recent mining works in Slovakia requires precise determination of the locations of the objects that constitute it. The objects in this register have their uniqueness linked with the history of mining in Slovakia. The state of positional accuracy in the registration of objects in its current form is unsatisfactory. Different database sources containing the locations of the old mining works are insufficient and show significant locational deviations. For this reason, it is necessary to precisely locate old mining works using modern measuring technologies. The most effective approach to solving this problem is the use of LiDAR data, which at the same time allow determining the position and above-ground shape of old mining works. Two localities with significant mining history were selected for this case study. Positional deviations in the location of old mining works among the selected data were determined from the register of old mining works in Slovakia, global navigation satellite system (GNSS) measurements, multidirectional hill-shading using LiDAR, and accessible data from the open street map. To compare the positions of identical old mining works from the selected database sources, we established differences in the coordinates (ΔX, ΔY) and calculated the positional deviations of the same objects. The average positional deviation in the total count of nineteen objects comparing documents, LiDAR data, and the register was 33.6 m. Comparing the locations of twelve old mining works between the LiDAR data and the open street map, the average positional deviation was 16.3 m. Between the data sources from GNSS and the registry of old mining works, the average positional deviation of four selected objects was 39.17 m.

scholarly journals HEIGHT DETERMINATION TECHNIQUES FOR THE NEXT NATIONAL HEIGHT SYSTEM OF FINLAND - A CASE STUDY

2015 ◽  
Vol 41 (4) ◽  
pp. 145-155
Author(s):  
Timo Saari ◽  
Markku Poutanen ◽  
Veikko Saaranen ◽  
Harri Kaartinen ◽  
Antero Kukko ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Pilot Project ◽  
Satellite System ◽  
Reference Station ◽  
Virtual Reference ◽  
Precise Levelling ◽  
Height Determination ◽  
Weak Points ◽  
Global Navigation Satellite

Precise levelling is known for its accuracy and reliability in height determination, but the process itself is slow, laborious and expensive. We have started a project to study methods for height determination that could decrease the creation time of national height systems without losing the accuracy and reliability that is needed for them. In the pilot project described here, we study some of the alternative techniques with a pilot field test where we compared them with the precise levelling. The purpose of the test is not to evaluate the mutual superiority or suitability of the techniques, but to establish the background for a larger test and to find strong and weak points of each technique. The techniques chosen for this study were precise levelling, Mobile Laser Scanning (MLS) and Global Navigation Satellite System (GNSS) levelling, which included static Global Positioning System (GPS) and Virtual Reference Station (VRS) measurements. This research highlighted the differences of the studied techniques and gave insights about the framework and procedure for the later experiments. The research will continue in a larger scale, where the suitability of the techniques regarding the height systems is to be determined.

On the phase detrending to disentangle refraction and diffraction on GNSS signals: a case study over Antarctica

2021 ◽  
Author(s):  
Luca Spogli ◽  
Hossein Ghobadi ◽  
Antonio Cicone ◽  
Lucilla Alfonsi ◽  
Claudio Cesaroni ◽  
...  
Keyword(s):  
Single Case ◽  
Cutoff Frequency ◽  
Satellite System ◽  
Fine Tuning ◽  
Scintillation Index ◽  
Ionospheric Scintillation ◽  
Iterative Filtering ◽  
Global Navigation Satellite ◽  
Value Changes

<p>We investigate the reliability of the phase scintillation index determined by receiving Global Navigation Satellite System (GNSS) signals at ground in the high-latitudes. To the scope, we report about the capabilities of recently introduced detrending scheme based on the signal decomposition provided by the Fast Iterative Filtering (FIF) technique. This detrending scheme enables a fine tuning of the cutoff frequency for phase detrending used in the phase scintillation index definition, aimed at disentangling diffraction and refraction effects. On a single case study based on GPS and Galileo data taken by a GNSS Ionospheric Scintillation Monitor Receiver (ISMR) in Concordia Station (Antarctica), we show how the FIF-based detrending allows deriving adaptive cutoff frequencies, whose value changes minute-by-minute. They are found to range between 0.4 Hz and 1.2 Hz. This allows better accounting for diffractive effects in phase scintillation index calculation and also showing the limitations on the use of such index, being still widely used in the community, both to characterize the features of ionospheric irregularities and to adopt mitigation solutions.</p>

scholarly journals Challenges Faced by Devolved Governance in Quality Service Delivery: A Case Study of Turkana Central Sub-county, Turkana County, Kenya

2017 ◽  
Vol 7 (4) ◽  
pp. 87
Author(s):  
James K. Sirite ◽  
Henry Ongori ◽  
Darius Bosire
Keyword(s):  
Service Delivery ◽  
Survey Design ◽  
Quality Service ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
County Governments ◽  
Policy Makers ◽  
To Come

The purpose of this study was to identify the challenges faced in quality service delivery to Turkana Central Sub-county citizens of Turkana County. The study used cross-sectional survey design. The sample size selected for the study was 261.  Data was collected using questionnaires and interview guides. Data was analyzed by descriptive statistics and presented in tables and figures for ease interpretation. The major findings of the study show that devolved governance faces some challenges. For instance the devolved governance is faced with corruption, lack of transparency and accountability and inadequate funds. This adversely   affects quality service delivery to its citizens. The findings of the study would inspire policy makers at the county and national government level to come up with appropriate strategies to mitigate the challenges identified in order to improve the quality of services offered by the county governments.

Leveraging Intelligent Compaction and Thermal Profiling Technologies to Improve Asphalt Pavement Construction Quality: A Case Study

2018 ◽  
Vol 2672 (26) ◽  
pp. 48-56 ◽  
Author(s):  
George K. Chang ◽  
Kiran Mohanraj ◽  
William A. Stone ◽  
Daniel J. Oesch ◽  
Victor (Lee) Gallivan
Keyword(s):  
Real Time ◽  
Satellite System ◽  
Material Transfer ◽  
Intelligent Compaction ◽  
Two Factors ◽  
Thermal Profiling ◽  
Compaction Control ◽  
Pavement Construction ◽  
Global Navigation Satellite

Intelligent compaction (IC) is an emerging technology with rollers equipped with global navigation satellite system (GNSS), an accelerometer-based measurement system, and an onboard color-coded display for real-time monitoring and compaction control. Paver-mounted thermal profiling (PMTP) is used to monitor asphalt surface temperatures behind a paver with a thermal scanner, and to track paver speeds, stops, and stop durations. Leveraging both IC and PMTP technologies allows for paving and compaction controls in real time, and for executing appropriate adjustments as needed. A case study is used to demonstrate the advantage of using both IC and PMTP over conventional operations. Postconstruction asphalt coring and tests, as well as pavement profile surveys were conducted to provide asphalt density data and pavement smoothness acceptance data for comparison and correlation analysis with IC and PMTP data. The data from 2 days of operations, one without the Material Transfer Vehicle (MTV) and another with the MTV, were analyzed and compared to illustrate the benefits of using IC, PMTP, and MTV for producing quality pavement products. Durability and smoothness are two key construction qualities for agencies and users of hot mix asphalt (HMA) pavements. These two factors also affect the long-term structural and functional pavement performance.

State of Watermain Infrastructure: A Canadian Case Study using Historic Pipe Break Datasets

2020 ◽  
Author(s):  
Brett Snider ◽  
Edward McBean
Keyword(s):  
Cast Iron ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
The Past ◽  
Survey Results ◽  
Pipe Break ◽  
Pipe Replacement ◽  
Better Than ◽  
Rate Threshold

Over the last two decades, a variety of reports have suggested that watermains in Canada are deteriorating, and break rates are increasing. However, these reports are often limited as the years of break records being utilized are brief; this paper revisits those assessments using over forty-five years of break records and shows that three of the five utilities investigated are experiencing significant decreases in break rates over the past 10 years while the two other utilities are maintaining consistent break rates. These results indicate that these utilities are effectively managing their watermain infrastructure, and suggest watermain infrastructure throughout Canada may be performing better than suggested by cross-sectional survey results. Analyses indicate that on average, 22% of the watermains analysed have exceeded the 0.125 brk/km/yr break rate threshold and may be considered for pipe replacement / rehabilitation. In particular 50% of cast iron pipes installed post-WWII have exceeded a break rate threshold of 0.125 brks/km/yr, suggesting large pipe replacement/rehabilitation of this pipe cohort is required.

Experimental results of multipath behavior for GPS L1-L2 and Galileo E1-E5b in static and kinematic scenarios

2019 ◽  
Vol 13 (4) ◽  
pp. 279-289 ◽  
Author(s):  
Alexandra Avram ◽  
Volker Schwieger ◽  
Noha El Gemayel
Keyword(s):  
Signal To Noise Ratio ◽  
Measurement Data ◽  
Absolute Error ◽  
Autonomous Driving ◽  
Satellite System ◽  
Natural Environments ◽  
Navigation Systems ◽  
Global Navigation Satellite ◽  
The Impact ◽  
Measurement Campaigns

Abstract Current trends like Autonomous Driving (AD) increase the need for a precise, reliable, and continuous position at high velocities. In both natural and man-made environments, Global Navigation Satellite System (GNSS) signals suffer challenges such as multipath, attenuation, or loss-of-lock. As Highway Assist and Highway Pilot are AD next steps, multipath knowledge is necessary for this typical user-case and kinematic situations. This paper presents a multipath performance analysis for GPS and Galileo satellites in static, slow, and high kinematic scenarios. The data is provided from car test-drives in both controlled and unrestricted, near-natural environments. The Code-Minus-Carrier (CMC) and cycle-slip implementations are validated with measurement data from consecutive days. Multipath statistical models based on satellite elevation are evaluated for the three investigated scenarios. Static models derived from the car setup measurements for GPS L1, L2 and Galileo E1 and E5b show a good agreement with a state-of-the-art model as well as the enhanced Galileo signals performance. Slow kinematic multipath results in a controlled environment showed an improvement for both navigation systems compared to the static measurements at the same place. This result is confirmed by static and slow kinematic multipath simulations with the same GNSS receiver. Post-processing analysis on highway measurements revealed a bigger multipath bias, compared to the open-sky static and slow kinematic measurement campaigns. Although less critical as urban or rural, this indicates the presence of multipath in this kind of environment as well. The impact of different parameters, including receiver architecture and Signal-to-noise ratio (SNR) are analyzed and discussed. Differential position (DGNSS) based on code is computed for each epoch and compared against GNSS/INS integrated position for all three measurement campaigns. The most significant 3D absolute error occurs where the greatest multipath envelope is found.

scholarly journals Assessment of Enhancing Transparency of Financial Statements

2016 ◽  
Vol 6 (2) ◽  
pp. 175
Author(s):  
Viswa Nadham N.
Keyword(s):  
Local Government ◽  
Local Governments ◽  
Opportunity To Learn ◽  
Financial Statements ◽  
Financial Statement ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
The Public ◽  
Qualitative And Quantitative

The study explored both the advantages of transparency and challenges facing finance departments of local government authorities in the course of preparing and presenting financial information. The study employed an explanatory case study,cross-sectional survey  and applied a triangulation of methods to collect both qualitative and quantitative data. The participants were all selected based on the opportunity to learn and the typicality of Dodoma municipality. A total of 80 respondents were involved. Data analysis was done through SPSS. Figures, tables, pattern matching, comparison and strong explanation building all aided in simplifying the analyses of findings.Key findings of the study unveiled that participation of the public in finance affairs of local governments heightened transparency in the preparation and presentation of financial statements. Furthermore, the finding reveal that International Finnancial Report Standards (IFRS) was rarely applicable during  the preparation of financial statement. It was also found out that tansparency in financial matters reduced fraudulent behaviours in the allocation and expenditure of local government funds.Key words: Financial statements, IFRS, IAS, Financial transperancy.

scholarly journals A Method to Improve the Distribution of Observations in GNSS Water Vapor Tomography

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2526 ◽  
Author(s):  
Fei Yang ◽  
Jiming Guo ◽  
Junbo Shi ◽  
Lv Zhou ◽  
Yi Xu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Precipitable Water ◽  
Absolute Error ◽  
Satellite System ◽  
Observation Data ◽  
Radiosonde Station ◽  
Satellite Signal ◽  
Comparative Results ◽  
Global Navigation Satellite ◽  
Vapor Distribution

Water vapor is an important driving factor in the related weather processes in the troposphere, and its temporal-spatial distribution and change are crucial to the formation of cloud and rainfall. Global Navigation Satellite System (GNSS) water vapor tomography, which can reconstruct the water vapor distribution using GNSS observation data, plays an increasingly important role in GNSS meteorology. In this paper, a method to improve the distribution of observations in GNSS water vapor tomography is proposed to overcome the problem of the relatively concentrated distribution of observations, enable satellite signal rays to penetrate more tomographic voxels, and improve the issue of overabundance of zero elements in a tomographic matrix. Numerical results indicate that the accuracy of the water vapor tomography is improved by the proposed method when the slant water vapor calculated by GAMIT is used as a reference. Comparative results of precipitable water vapor (PWV) and water vapor density (WVD) profiles from radiosonde station data indicate that the proposed method is superior to the conventional method in terms of the mean absolute error (MAE), standard deviations (STD), and root-mean-square error (RMS). Further discussion shows that the ill-condition of tomographic equation and the richness of data in the tomographic model need to be discussed separately.

scholarly journals The relationship between e-CRM and customer loyalty: a Kenyan Commercial Bank case study

2017 ◽  
Vol 12 (2) ◽  
pp. 106-115 ◽  
Author(s):  
Eric E. Mang’unyi ◽  
Oumar T. Khabala ◽  
Krishna K. Govender
Keyword(s):  
Customer Loyalty ◽  
Survey Design ◽  
Commercial Banking ◽  
Customer Relationship ◽  
Cross Sectional Survey ◽  
Design Data ◽  
Cross Sectional ◽  
Convenience Sample ◽  
The Relationship

Since customer loyalty is key, especially in the highly competitive commercial banking environment, this article evaluated the effects of features of electronic customer relationship management (e-CRM) on customer loyalty. Using a cross-sectional survey design, data were collected from a convenience sample of customers of a major international Kenyan bank using self-administered questionnaires. The findings based on correlation and multiple regression analyses, revealed that pre-service, during (the) service and post transactional e-CRM features have a positive and significant relationship with loyalty, and that the pre-service and during service features significantly predict loyalty. Thus, enhancing e-CRM practices could be a strategic competitive tool to impact the banks’ relationship with their customers.

Sign in / Sign up

Export Citation Format

Share Document