scholarly journals Tracking Fluorescent Dye Dispersion from an Unmanned Aerial Vehicle

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3905
Author(s):  
Pawel Burdziakowski ◽  
Piotr Zima ◽  
Pawel Wielgat ◽  
Dominika Kalinowska
Keyword(s):  
Fluorescent Dyes ◽  
Dispersion Model ◽  
Image Data ◽  
Tracer Concentration ◽  
Fluorescent Tracer ◽  
Model Image ◽  
Aerial Vehicle ◽  
Rhodamine Wt ◽  
New Phenomena ◽  
Discrete Grid

Commercial unmanned aerial vehicles continue to gain popularity and their use for collecting image data and recording new phenomena is becoming more frequent. This study presents an effective method for measuring the concentration of fluorescent dyes (fluorescein and Rhodamine WT) for the purpose of providing a mathematical dispersion model. Image data obtained using a typical visible-light camera was used to measure the concentration of the dye floating on water. The reference measurement was taken using a laboratory fluorometer. The article presents the details of three extensive measurement sessions and presents elements of a newly developed method for measuring fluorescent tracer concentrations. The said method provides tracer concentration maps presented on the example of an orthophoto within a 2 × 2 m discrete grid.

scholarly journals Spatio-Temporal Change Monitoring of Outside Manure Piles Using Unmanned Aerial Vehicle Images

Drones ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Geonung Park ◽  
Kyunghun Park ◽  
Bonggeun Song
Keyword(s):  
Point Source ◽  
Laser Scanning ◽  
Image Data ◽  
Surface Model ◽  
Point Source Pollution ◽  
Efficient Management ◽  
Aerial Vehicle ◽  
Spatio Temporal ◽  
Agricultural Areas ◽  
Water Quality Deterioration

Water quality deterioration due to outdoor loading of livestock manure requires efficient management of outside manure piles (OMPs). This study was designed to investigate OMPs using unmanned aerial vehicles (UAVs) for efficient management of non-point source pollution in agricultural areas. A UAV was used to acquire image data, and the distribution and cover installation status of OMPs were identified through ortho-images; the volumes of OMP were calculated using digital surface model (DSM). UAV- and terrestrial laser scanning (TLS)-derived DSMs were compared for identifying the accuracy of calculated volumes. The average volume accuracy was 92.45%. From April to October, excluding July, the monthly average volumes of OMPs in the study site ranged from 64.89 m3 to 149.69 m3. Among the 28 OMPs investigated, 18 were located near streams or agricultural waterways. Establishing priority management areas among the OMP sites distributed in a basin is possible using spatial analysis, and it is expected that the application of UAV technology will contribute to the efficient management of OMPs and other non-point source pollutants.

scholarly journals UAV-Driven Structural Crack Detection and Location Determination Using Convolutional Neural Networks

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2650
Author(s):  
Daegyun Choi ◽  
William Bell ◽  
Donghoon Kim ◽  
Jichul Kim
Keyword(s):  
Visual Information ◽  
Crack Detection ◽  
Image Data ◽  
Image Processing Techniques ◽  
Location Determination ◽  
Aerial Vehicle ◽  
Using Data ◽  
Processing Techniques ◽  
Deep Learning Model ◽  
Structural Cracks

Structural cracks are a vital feature in evaluating the health of aging structures. Inspectors regularly monitor structures’ health using visual information because early detection of cracks on highly trafficked structures is critical for maintaining the public’s safety. In this work, a framework for detecting cracks along with their locations is proposed. Image data provided by an unmanned aerial vehicle (UAV) is stitched using image processing techniques to overcome limitations in the resolution of cameras. This stitched image is analyzed to identify cracks using a deep learning model that makes judgements regarding the presence of cracks in the image. Moreover, cracks’ locations are determined using data from UAV sensors. To validate the system, cracks forming on an actual building are captured by a UAV, and these images are analyzed to detect and locate cracks. The proposed framework is proven as an effective way to detect cracks and to represent the cracks’ locations.

RTD Measurement, Modeling, and Analysis of Liquid Phase of Three-Tube Industrial Pulp Digester

2019 ◽  
Vol 17 (4) ◽  
Author(s):  
Meenakshi Sheoran ◽  
Avinash Chandra ◽  
Sanjeev Ahuja ◽  
Haripada Bhunia ◽  
Harish J. Pant
Keyword(s):  
Liquid Phase ◽  
Flow Regime ◽  
Residence Time ◽  
Dispersion Model ◽  
Flow Behavior ◽  
Plug Flow ◽  
Hydrodynamic Performance ◽  
Concentration Data ◽  
Tracer Concentration ◽  
Dispersion Number

Abstract Residence-time distribution (RTD) experiments were performed to analyze an industrial scale three-tube series continuous pulping digester’s hydrodynamic performance. An impulse of radiotracer 82Br (γ energy source) was introduced at the inlet of the first tube. The radiotracer concentration in the liquid phase was traced at the outlet of each tube. The input behavior of the radiotracer converted to a non-ideal pulse tracer input for the second and third tubes of the digester. Numerical convolution is adopted to deal with the non-ideal pulse input of the radiotracer. A modeling procedure for determining the RTD from the outlet tracer concentration data is proposed. A plug flow component followed by axial dispersion model is considered, and is adjusted after its convolution with the inlet tracer concentration data to obtain the RTD of the individual tubes. The obtained RTD data are analyzed to explain the flow behavior, degree of dispersion, and flow abnormalities existing in the digester. The mean residence-time (MRT), and dispersion number are estimated for the model components for the three tubes. The vessel dispersion number is found to decrease from tube 1 to tube 3. Overall, the conversion of the highly dispersed flow regime into the plug-flow regime is observed in the whole digester.

scholarly journals Novel Use of Vitamin B2 as a Fluorescent Tracer in Aerosol and Droplet Contamination Models in Otolaryngology

2020 ◽  
pp. 000348942094958
Author(s):  
Edward S. Sim ◽  
Harish Dharmarajan ◽  
Devi Sai Sri Kavya Boorgu ◽  
Lindsey Goyal ◽  
Michael Weinstock ◽  
...  
Keyword(s):  
Nasal Cavity ◽  
Fluorescent Dyes ◽  
Uv Light ◽  
Human Subjects ◽  
Particle Dispersion ◽  
Mitigation Measures ◽  
Dispersion Pattern ◽  
Vitamin B2 ◽  
Fluorescent Tracers ◽  
Fluorescent Tracer

Objective: During the COVID-19 era, a reliable method for tracing aerosols and droplets generated during otolaryngology procedures is needed to accurately assess contamination risk and to develop mitigation measures. Prior studies have not investigated the reliability of different fluorescent tracers for the purpose of studying aerosols and small droplets. Objectives include (1) comparing vitamin B2, fluorescein, and a commercial fluorescent green dye in terms of particle dispersion pattern, suspension into aerosols and small droplets, and fluorescence in aerosolized form and (2) determining the utility of vitamin B2 as a fluorescent tracer coating the aerodigestive tract mucosa in otolaryngology contamination models. Methods: Vitamin B2, fluorescein, and a commercial fluorescent dye were aerosolized using a nebulizer and passed through the nasal cavity from the trachea in a retrograde-intubated cadaveric head. In another scenario, vitamin B2 was irrigated to coat the nasal cavity and nasopharyngeal mucosa of a cadaveric head for assessment of aerosol and droplet generation from endonasal drilling. A cascade impactor was used to collect aerosols and small droplets ≤14.1 µm based on average aerodynamic diameter, and the collection chambers were visualized under UV light. Results: When vitamin B2 was nebulized, aerosols ≤5.4 µm were generated and the collected particles were fluorescent. When fluorescein and the commercial water tracer dye were nebulized, aerosols ≤8.61 µm and ≤2.08 µm respectively were generated, but the collected aerosols did not appear visibly fluorescent. Endonasal drilling in the nasopharynx coated with vitamin B2 irrigation yielded aerosols ≤3.30 µm that were fluorescent under UV light. Conclusion: Vitamin B2’s reliability as a fluorescent tracer when suspended in aerosols and small droplets ≤14.1 µm and known mucosal safety profile make it an ideal compound compared to fluorescein and commercial water-based fluorescent dyes for use as a safe fluorescent tracer in healthcare contamination models especially with human subjects.

scholarly journals Object Segmentation on UAV Photo Data to Support the Provision of Rural Area Spatial Information

2015 ◽  
Vol 29 (1) ◽  
Author(s):  
Nurwita Mustika Sari ◽  
Dony Kushardono
Keyword(s):  
Rural Area ◽  
Rural Areas ◽  
Spatial Information ◽  
Remote Sensing Data ◽  
Image Data ◽  
Aerial Photographs ◽  
Segmentation Method ◽  
Object Based ◽  
Aerial Vehicle ◽  
Uav Image

The use of Unmanned Aerial Vehicle (UAV) to take aerial photographs is increasing in recent years. Photo data taken by UAV become one of reliable detailed-scale  remote sensing data sources. The capability to obtain cloud-free images and the flexibility of time are some of the advantages of UAV photo data compared to satellite images with optical sensor. Displayed area at the data shows the objects clearly. Rural area has certain characteristics in its land cover namely ricefield. To delineate the area correctly there is an object-based image analysis methods (OBIA) that could be applied. In this  study, proposed a novel method to  execute the separation of objects that exist in the data with segmentation method. The result shows an effective segmentation method to separate different objects in rural areas recorded on UAV image data. The accuracy obtained is 90.47% after optimization process. This segmentation can be a valid basis to support the provision of spatial information in rural area.

scholarly journals Surface modelling of a unique heritage object: use of UAV combined with camera and LiDAR for mound inspection

2020 ◽  
Author(s):  
Dainora Jankauskiene ◽  
◽  
Indrius Kuklys ◽  
Lina Kukliene ◽  
Birute Ruzgiene ◽  
...  
Keyword(s):  
Image Data ◽  
Time Duration ◽  
Ground Sample ◽  
Surface Modelling ◽  
Object Use ◽  
Aerial Mapping ◽  
Aerial Vehicle ◽  
Low Altitude ◽  
Images Processing ◽  
Very High

Nowadays, the use of Unmanned Aerial Vehicle flying at a low altitude in conjunction with photogrammetric and LiDAR technologies allows to collect images of very high-resolution to generate dense points cloud and to simulate geospatial data of territories. The technology used in experimental research contains reconstruction of topography of surface with historical structure, observing the recreational infrastructure, obtaining geographic information for users who are involved in preservation and inspection of such unique cultural/ heritage object as are mounds in Lithuania. In order to get reliable aerial mapping products of preserved unique heritage object, such photogrammetric/ GIS procedures were performed: UAV flight for taking images with the camera; scanning surface by LiDAR simultaneously; processing of image data, 3D modelling and generation of orthophoto. Evaluation of images processing results shows that the accuracy of surface modelling by the use of UAV photogrammetry method satisfied requirements – mean RMSE equal to 0.031 m. The scanning surface by LiDAR from low altitude is advisable, relief representation of experimental area was obtained with mean accuracy up to 0.050 m. Aerial mapping by the use of UAV requires to specify appropriate ground sample distance (GSD) that is important for reducing number of images and time duration for modelling of area. Experiment shows that specified GSD of 1.7 cm is not reasonable, GSD size increased by 1.5 time would be applicable. The use of different software in addition for DSM visualization and analysis is redundant action.

scholarly journals ESTIMATION OF DATA MEMORY CAPACITY FOR CIRCULARLY POLARIZED SYNTHETIC APERTURE RADAR ONBOARD UNMANNED AERIAL VEHICLE PLATFORM (CP-SAR UAV)

2011 ◽  
Vol 7 (1) ◽  
Author(s):  
P. Rizki Akbar ◽  
J.T. Sri Sumantyo ◽  
V.C.Koo ◽  
H.Kuzel
Keyword(s):  
Synthetic Aperture Radar ◽  
Unmanned Aerial Vehicle ◽  
Early Stage ◽  
Low Cost ◽  
Image Data ◽  
Memory Capacity ◽  
Synthetic Aperture ◽  
Circularly Polarized ◽  
Aerial Vehicle ◽  
Aperture Radar

Previously only linear polarization is widely used in the Synthetic Aperture Radar(SAR) system onboard spaceborne and airborne platforms. In such linearly polarized SAR(LP-SAR) systems, Faraday rotation in the ionosphere and platform posture will contribute tothe system noise. Therefore to improve this situation, currently a novel Circularly PolarizedSynthetic Aperture Radar (CP-SAR) sensor is developed in Microwave Remote SensingLaboratory, Chiba University. Moreover, from this research, a new backscattering data basedon circularly polarized wave in the remote sensing field can be obtained. As an early stage ofthe development of this CP-SAR sensor, we built an Unmanned Aerial Vehicle (UAV)platform for testing CP-SAR sensor capabilities. In this paper, we describe the novel CP-SARsensor and the method to design CP-SAR UAV especially in estimating the requirement ofdata memory capacity. Also a smaller antenna is possible to be implemented since the 3-dBaxial ratio on antenna characteristic becomes the main parameter in this new CP-SARtechnique. Hence, a compact CP-SAR sensor onboard a small and low cost spaceborneplatform yielding a high accuracy SAR image data can be realized in the near future.

Modelling of Flow of a Liquid in Apparatus with Mobile Packing: Dispersion Model

1993 ◽  
Vol 58 (9) ◽  
pp. 2047-2058
Author(s):  
Zdeněk Palatý
Keyword(s):  
Differential Equation ◽  
Numerical Integration ◽  
Residence Time ◽  
Mean Residence Time ◽  
Peclet Number ◽  
Dispersion Model ◽  
Tracer Concentration ◽  
Optimization Of Parameters ◽  
Determination Of Parameters

The paper deals with determination of parameters of a dispersion model used for describing the flow of liquid on a plate with mobile packing in the region of gas velocities up to 1.5 m s-1. The parameters of the model - the diffusion Peclet number and mean residence time of liquid - were determined from the nonideal input impulse of tracer concentration and its response by the method of numerical integration of differential equation with subsequent optimization of parameters. The results of measurements are presented graphically and in the form of criterion equations.

scholarly journals Coral Reef Mapping of UAV: A Comparison of Sun Glint Correction Methods

2019 ◽  
Vol 11 (20) ◽  
pp. 2422 ◽  
Author(s):  
Muslim ◽  
Chong ◽  
Safuan ◽  
Khalil ◽  
Hossain
Keyword(s):  
Coral Reef ◽  
Image Data ◽  
Peninsular Malaysia ◽  
Coral Rubble ◽  
Distribution Mapping ◽  
Multi Temporal ◽  
Aerial Vehicle ◽  
Accuracy Result ◽  
Uav Image ◽  
Removal Technique

Although methods were proposed for eliminating sun glint effects from airborne and satellite images over coral reef environments, a method was not proposed previously for unmanned aerial vehicle (UAV) image data. De-glinting in UAV image analysis may improve coral distribution mapping accuracy result compared with an uncorrected image classification technique. The objective of this research was to determine accuracy of coral reef habitat classification maps based on glint correction methods proposed by Lyzenga et al., Joyce, Hedley et al., and Goodman et al.. The UAV imagery collected from the coral-dominated Pulau Bidong (Peninsular Malaysia) on 20 April 2016 was analyzed in this study. Images were pre-processed with the following two strategies: Strategy-1 was the glint removal technique applied to the whole image, while Strategy-2 used only the regions impacted by glint instead of the whole image. Accuracy measures for the glint corrected images showed that the method proposed by Lyzenga et al. following Strategy-2 could eliminate glints over the branching coral—Acropora (BC), tabulate coral—Acropora + Montipora (TC), patch coral (PC), coral rubble (R), and sand (S) with greater accuracy than the other four methods using Strategy-1. Tested in two different coral environments (Site-1: Pantai Pasir Cina and Site-2: Pantai Vietnam), the glint-removed UAV imagery produced reliable maps of coral habitat distribution with finer details. The proposed strategies can potentially be used to remove glint from UAV imagery and may improve usability of glint-affected imagery, for analyzing spatiotemporal changes of coral habitats from multi-temporal UAV imagery.

scholarly journals Vision Analysis System for Autonomous Landing of Micro Drone

2014 ◽  
Vol 8 (4) ◽  
pp. 199-203 ◽  
Author(s):  
Marcin Skoczylas
Keyword(s):  
Image Data ◽  
Ccd Camera ◽  
Image Transmission ◽  
Base Station ◽  
Image Features ◽  
Feature Detector ◽  
Autonomous Landing ◽  
Radio Broadcasting ◽  
Aerial Vehicle ◽  
Analysis System

Abstract This article describes a concept of an autonomous landing system of UAV (Unmanned Aerial Vehicle). This type of device is equipped with the functionality of FPV observation (First Person View) and radio broadcasting of video or image data. The problem is performance of a system of autonomous drone landing in an area with dimensions of 1m × 1m, based on CCD camera coupled with an image transmission system connected to a base station. Captured images are scanned and landing marker is detected. For this purpose, image features detectors (such as SIFT, SURF or BRISK) are utilized to create a database of keypoints of the landing marker and in a new image keypoints are found using the same feature detector. In this paper results of a framework that allows detection of defined marker for the purpose of drone landing field positioning will be presented.

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