scholarly journals CALIBRATION OF LOW COST RGB AND NIR UAV CAMERAS

2016 ◽  
Vol XLI-B1 ◽  
pp. 817-821
Author(s):  
A. Fryskowska ◽  
M. Kedzierski ◽  
A. Grochala ◽  
A. Braula
Keyword(s):  
Comparative Analysis ◽  
3D Modeling ◽  
Low Cost ◽  
Digital Cameras ◽  
Digital Elevation ◽  
Calibration Methods ◽  
Historical Sites ◽  
Orientation Parameters ◽  
Terrestrial Photogrammetry

Non-metric digital cameras are being widely used for photogrammetric studies. The increase in resolution and quality of images obtained by non-metric cameras, allows to use it in low-cost UAV and terrestrial photogrammetry. Imagery acquired with non-metric cameras can be used in 3D modeling of objects or landscapes, reconstructing of historical sites, generating digital elevation models (DTM), orthophotos, or in the assessment of accidents. <br><br> Non-metric digital camcorders are characterized by instability and ignorance of the interior orientation parameters. Therefore, the use of these devices requires prior calibration. Calibration research was conducted using non-metric camera, different calibration tests and various software. <br><br> The first part of the paper contains a brief theoretical introduction including the basic definitions, like the construction of non-metric cameras or description of different optical distortions. The second part of the paper contains cameras calibration process, details of the calibration methods and models that have been used. Sony Nex 5 camera calibration has been done using software: Image Master Calib, Matlab - Camera Calibrator application and Agisoft Lens. For the study 2D test fields has been used. As a part of the research a comparative analysis of the results have been done.

scholarly journals CALIBRATION OF LOW COST RGB AND NIR UAV CAMERAS

2016 ◽  
Vol XLI-B1 ◽  
pp. 817-821 ◽  
Author(s):  
A. Fryskowska ◽  
M. Kedzierski ◽  
A. Grochala ◽  
A. Braula
Keyword(s):  
Comparative Analysis ◽  
3D Modeling ◽  
Low Cost ◽  
Digital Cameras ◽  
Digital Elevation ◽  
Calibration Methods ◽  
Historical Sites ◽  
Orientation Parameters ◽  
Terrestrial Photogrammetry

Non-metric digital cameras are being widely used for photogrammetric studies. The increase in resolution and quality of images obtained by non-metric cameras, allows to use it in low-cost UAV and terrestrial photogrammetry. Imagery acquired with non-metric cameras can be used in 3D modeling of objects or landscapes, reconstructing of historical sites, generating digital elevation models (DTM), orthophotos, or in the assessment of accidents. &lt;br&gt;&lt;br&gt; Non-metric digital camcorders are characterized by instability and ignorance of the interior orientation parameters. Therefore, the use of these devices requires prior calibration. Calibration research was conducted using non-metric camera, different calibration tests and various software. &lt;br&gt;&lt;br&gt; The first part of the paper contains a brief theoretical introduction including the basic definitions, like the construction of non-metric cameras or description of different optical distortions. The second part of the paper contains cameras calibration process, details of the calibration methods and models that have been used. Sony Nex 5 camera calibration has been done using software: Image Master Calib, Matlab - Camera Calibrator application and Agisoft Lens. For the study 2D test fields has been used. As a part of the research a comparative analysis of the results have been done.

scholarly journals Comparative Analysis of QoS Management and Technical Requirements in 3GPP Standards for Cellular IoT Technologies

2018 ◽  
Vol 2 ◽  
pp. 41-47 ◽  
Author(s):  
Valery Tikhvinskiy ◽  
Grigory Bochechka ◽  
Andrey Gryazev ◽  
Altay Aitmagambetov
Keyword(s):  
Comparative Analysis ◽  
New Technologies ◽  
Narrow Band ◽  
Low Cost ◽  
Low Latency ◽  
Qos Management ◽  
Technical Requirements ◽  
Iot Devices ◽  
Positive Results

Optimization of 3GPP standards that apply to cellular technologies and their adaptation to LPWAN has not led to positive results only enabling to compete on the market with the growing number non-cellular greenfield LPWAN technologies – LoRa, Sigfox and others. The need to take into consideration, during the 3GPP standard optimization phase, the low-cost segment of narrow-band IoT devices relying on such new technologies as LTE-M, NB-IoT and EC-GSM, has also led to a loss of a number of technical characteristics and functions that offered low latency and guaranteed the quality of service. The aim of this article is therefore to review some of the most technical limitations and restrictions of the new 3GPP IoT technologies, as well as to indicate the direction for development of future standards applicable to cellular IoT technologies.

scholarly journals Metrological Challenges in Collaborative Sensing: Applicability of Digital Calibration Certificates

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4730
Author(s):  
Tuukka Mustapää ◽  
Pekka Nikander ◽  
Daniel Hutzschenreuter ◽  
Raine Viitala
Keyword(s):  
Low Cost ◽  
Industrial Applications ◽  
Digital Calibration ◽  
Self Calibration ◽  
Chain Link ◽  
Calibration Methods ◽  
Collaborative Sensing ◽  
Future Work ◽  
Metrology Infrastructure

IoT systems based on collaborative sensor networks are becoming increasingly common in various industries owing to the increased availability of low-cost sensors. The quality of the data provided by these sensors may be unknown. For these reasons, advanced data processing and sensor network self-calibration methods have become popular research topics. In terms of metrology, the self-calibration methods lack the traceability to the established measurement standards of National Metrology Institutes (NMIs) through an unbroken chain-link of calibration. This problem can be solved by the ongoing digitalization of the metrology infrastructure. We propose a conceptual solution based on Digital Calibration Certificates (DCCs), Digital SI (D-SI), and cryptographic digital identifiers, for validation of data quality and trustworthiness. The data that enable validation and traceability can be used to improve analytics, decision-making, and security in industrial applications. We discuss the applicability and benefits of our solutions in a selection of industrial use cases, where collaborative sensing has already been introduced. We present the remaining challenges in the digitization and standardization processes regarding digital metrology and the future work required to address them.

Evaluation of Low Cost Digital Cameras for Producing Photogrammetric Output from UAV

2018 ◽  
Vol 7 (2.29) ◽  
pp. 792 ◽  
Author(s):  
Syafiq Sukor ◽  
Anuar Ahmad
Keyword(s):  
Global Positioning System ◽  
Mean Squared Error ◽  
Low Cost ◽  
Control Point ◽  
Ground Control ◽  
Digital Cameras ◽  
Squared Error ◽  
Digital Elevation ◽  
Global Positioning ◽  
Elevation Model

Recently there a lot of improvement in digital photogrammetry and this allow photogrammetry to become faster and cheaper . This study discuss about two type of low cost camera which is the compact camera (Canon Power Shot SX230 ) and action camera (Xiaomi yi) where both of them have different lens distortion. This study is conducted within UTM (Universiti Teknologi Malaysia) Skudai campus at Kolej  Tun Razak. Both of the Canon Power Shot SX230 and Xiaomi yi camera would be attach to the UAV  to take aerial photo with three different altitude which is 60 meter, 80 meter and 100 meter with a similar flight path. Check point (CPs) and Ground control point (GCPs) were also established using rapid static technique of Global Positioning System (GPS) and Total Station. The Canon Power Shot SX230 and Xiaomi yi camera is then calibrated using checkboard calibration this is done by using Agisoft  Lens software. Then all of the pictures that been taken by the Canon Power Shot SX230 and the Xiaomi yi would be processed by using Agisoft Photoscan software to generate Digital Elevation Model (DEM), orthophoto and contour line. The accuracy of DEM was determined based on Root Mean Squared Error (RMSE) value. Both of the result is then analyze visually and statically. Overall both of the camera gives a slight different in accuracy. 

scholarly journals Quality of Digital Elevation Models obtained from Unmanned Aerial Vehicles for Precision Viticulture

OENO One ◽  
2016 ◽  
Vol 50 (3) ◽  
Author(s):  
Léo Pichon ◽  
Arnaud Ducanchez ◽  
Hélène Fonta ◽  
Bruno Tisseyre
Keyword(s):  
Low Cost ◽  
Wine Industry ◽  
Image Capture ◽  
Digital Elevation ◽  
Elevation Data ◽  
Aerial Vehicle ◽  
Elevation Model ◽  
Uav Images ◽  
Data Acquisition And Processing

<p style="text-align: justify;"><strong>Aims:</strong> This work aims to study the quality of low cost Digital Surface Models (DSMs) obtained with Unmanned Aerial Vehicle (UAV) images and to test whether these DSMs meet common requirements of the wine industry.</p><p style="text-align: justify;"><strong>Methods and results: </strong>Experiments were carried out on a 4-ha vineyard located 10 km north of Beziers (France). The experimental site presents slope and aspect variations representative of mechanised commercial vineyards in Languedoc Roussillon. DSMs were provided by three UAV companies selected for the diversity of their solutions in terms of image capture altitude, type of UAV and image processing software. DSMs were obtained by photogrammetry and correspond to commercial products usually delivered by UAV companies. DSMs from UAV were compared to a reference Digital Elevation Model (DEM) acquired by a laser tachymeter. Four indicators were used to test the quality of DSMs: the mean error and its dispersion in the XY plane and in elevation Z. Results show a good georeferencing of the DSMs (MeanErrorXY&lt;10 cm) and a similar quality in elevation (MeanErrorZ&lt;10 cm) estimation. Results also show that the error in elevation is highly spatially structured. The spatial patterns observed did not depend on the elevation and could be related to algorithms used to compute the DSMs.</p><p style="text-align: justify;"><strong>Conclusion: </strong>Data acquisition and processing methods have an impact on the quality of the DSMs provided by the UAV companies. DSM qualities are good enough to meet commercial vineyard requirements. The tested DSMs fit the requirements to assess field characteristics (elevation, slope, aspects) which may be important for terroir characterisation purposes.</p><p style="text-align: justify;"><strong>Significance and impact of the study:</strong> This study proves that elevation data derived from UAV present an accuracy equivalent to the reference system used in this study. The rapidity, the low cost and the high spatial resolution of these data offer significant opportunities for the development of new services for the wine industry for field characterisation.</p>

Low-cost telemedicine in the developing world

2002 ◽  
Vol 8 (3_suppl) ◽  
pp. 63-65 ◽  
Author(s):  
R Swinfen ◽  
P Swinfen
Keyword(s):  
Solomon Islands ◽  
Low Cost ◽  
The Internet ◽  
Digital Cameras ◽  
Computer Viruses ◽  
Charitable Trust ◽  
Set Up ◽  
The Uk ◽  
Medicolegal Issues

summary The Swinfen Charitable Trust uses digital cameras and email to provide specialist advice to doctors in developing countries. The first telemedicine link was set up in July 1999. By the end of a year there were three links to hospitals in Bangladesh, Nepal and the Solomon Islands. Initially the consultants, all of whom give their advice free of charge, were from the UK, but now are worldwide. At present there are 12 links in operation, including one on Tristan da Cunha, and two links approved and awaiting equipment. The advice given by the consultants has been found to be helpful to the referring doctors and to benefit their patients. Failures have been due to the use of obsolescent equipment, computer viruses, lack of communication with the referring hospital before setting up a link, and referring doctors not chasing up their own referrals. Problems yet to be solved include the unreliability of the Internet, certain medicolegal issues and assessing the quality of medical consultants. In future there will be the problem of managing a rapidly growing telemedicine network.

scholarly journals EVALUATION OF LOW-COST TERRESTRIAL PHOTOGRAMMETRY FOR 3D RECONSTRUCTION OF COMPLEX BUILDINGS

2017 ◽  
Vol IV-2/W4 ◽  
pp. 199-206 ◽  
Author(s):  
S. Altman ◽  
W. Xiao ◽  
B. Grayson
Keyword(s):  
Natural Disaster ◽  
Point Cloud ◽  
Low Cost ◽  
Point Clouds ◽  
3D Modelling ◽  
Negative Effects ◽  
Accessible Method ◽  
Digital Modelling ◽  
Terrestrial Photogrammetry

Terrestrial photogrammetry is an accessible method of 3D digital modelling, and can be done with low-cost consumer grade equipment. Globally there are many undocumented buildings, particularly in the developing world, that could benefit from 3D modelling for documentation, redesign or restoration. Areas with buildings at risk of destruction by natural disaster or war could especially benefit. This study considers a range of variables that affect the quality of photogrammetric results. Different point clouds of the same building are produced with different variables, and they are systematically tested to see how the output was affected. This is done by geometrically comparing them to a laser scanned point cloud of the same building. It finally considers how best results can be achieved for different applications, how to mitigate negative effects, and the limits of this technique.

scholarly journals Suggestions to Limit Geometric Distortions in the Reconstruction of Linear Coastal Landforms by SfM Photogrammetry with PhotoScan® and MicMac® for UAV Surveys with Restricted GCPs Pattern

Drones ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 2 ◽  
Author(s):  
Marion Jaud ◽  
Sophie Passot ◽  
Pascal Allemand ◽  
Nicolas Le Dantec ◽  
Philippe Grandjean ◽  
...  
Keyword(s):  
Low Cost ◽  
Software Tool ◽  
Rapid Acquisition ◽  
Geometric Distortions ◽  
Ground Control Points ◽  
Digital Elevation ◽  
Coastal Landforms ◽  
Elevation Model ◽  
Camera Distortion

Owing to the combination of technological progress in Unmanned Aerial Vehicles (UAVs) and recent advances in photogrammetry processing with the development of the Structure-from-Motion (SfM) approach, UAV photogrammetry enables the rapid acquisition of high resolution topographic data at low cost. This method is particularly widely used for geomorphological surveys of linear coastal landforms. However, linear surveys are generally pointed out as problematic cases because of geometric distortions creating a “bowl effect” in the computed Digital Elevation Model (DEM). Secondly, the survey of linear coastal landforms is associated with peculiar constraints for Ground Control Points (GCPs) measurements and for the spatial distribution of the tie points. This article aims to assess the extent of the bowl effects affecting the DEM generated above a linear beach with a restricted distribution of GCPs, using different acquisition scenarios and different processing procedures, both with PhotoScan® software tool and MicMac® software tool. It appears that, with a poor distribution of the GCPs, a flight scenario that favors viewing angles diversity can limit DEM’s bowl effect. Moreover, the quality of the resulting DEM also depends on the good match between the flight plan strategy and the software tool via the choice of a relevant camera distortion model.

scholarly journals Quality of Digital Elevation Models obtained from Unmanned Aerial Vehicles for Precision Viticulture

OENO One ◽  
2016 ◽  
Vol 50 (3) ◽  
Author(s):  
Léo Pichon ◽  
Arnaud Ducanchez ◽  
Hélène Fonta ◽  
Bruno Tisseyre
Keyword(s):  
Low Cost ◽  
Wine Industry ◽  
Image Capture ◽  
Digital Elevation ◽  
Elevation Data ◽  
Aerial Vehicle ◽  
Elevation Model ◽  
Uav Images ◽  
Data Acquisition And Processing

Aims: This work aims to study the quality of low cost Digital Surface Models (DSMs) obtained with Unmanned Aerial Vehicle (UAV) images and to test whether these DSMs meet common requirements of the wine industry.Methods and results: Experiments were carried out on a 4-ha vineyard located 10 km north of Beziers (France). The experimental site presents slope and aspect variations representative of mechanised commercial vineyards in Languedoc Roussillon. DSMs were provided by three UAV companies selected for the diversity of their solutions in terms of image capture altitude, type of UAV and image processing software. DSMs were obtained by photogrammetry and correspond to commercial products usually delivered by UAV companies. DSMs from UAV were compared to a reference Digital Elevation Model (DEM) acquired by a laser tachymeter. Four indicators were used to test the quality of DSMs: the mean error and its dispersion in the XY plane and in elevation Z. Results show a good georeferencing of the DSMs (MeanErrorXY<10 cm) and a similar quality in elevation (MeanErrorZ<10 cm) estimation. Results also show that the error in elevation is highly spatially structured. The spatial patterns observed did not depend on the elevation and could be related to algorithms used to compute the DSMs.Conclusion: Data acquisition and processing methods have an impact on the quality of the DSMs provided by the UAV companies. DSM qualities are good enough to meet commercial vineyard requirements. The tested DSMs fit the requirements to assess field characteristics (elevation, slope, aspects) which may be important for terroir characterisation purposes.Significance and impact of the study: This study proves that elevation data derived from UAV present an accuracy equivalent to the reference system used in this study. The rapidity, the low cost and the high spatial resolution of these data offer significant opportunities for the development of new services for the wine industry for field characterisation.

scholarly journals PERFORMANCE EVALUATION OF NON-METRIC DIGITAL CAMERA FOR PHOTOGRAMMETRIC APPLICATION

2012 ◽  
Vol 31 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Birutė Ruzgienė
Keyword(s):  
Field Experiments ◽  
Low Cost ◽  
Digital Camera ◽  
Ccd Camera ◽  
Test Field ◽  
Digital Cameras ◽  
Close Range ◽  
Orientation Parameters ◽  
Poor Stability

During the last year amateur low‐cost digital cameras are increasingly expected to contribute to the digital photogrammetry. An important aspect of the suitability of these cameras is determination of their geometrical instability. In order to evaluate amateur digital camera performance, small format, low resolution and low-cost CCD camera have been investigated in two considerations: determining inner orientation parameters at different time and estimating accuracy in test field experiments. The calibration results demonstrate the poor stability of such a digital camera. As a result of the instability, amateur cameras have limited possibilities in close-range photogrammetry. However, the investigated camera under certain limited accuracy requirements can be used for low-accuracy photogrammetric application.

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