Geometric Calibration of Digital Cameras for 3D Cumulus Cloud Measurements

2009 ◽  
Vol 26 (2) ◽  
pp. 200-214 ◽  
Author(s):  
Jiuxiang Hu ◽  
Anshuman Razdan ◽  
Joseph A. Zehnder
Keyword(s):  
Field Measurements ◽  
Geometric Error ◽  
Digital Cameras ◽  
Cumulus Clouds ◽  
Geometric Calibration ◽  
Earth Observing System ◽  
Stereo Photogrammetry ◽  
Camera Parameters ◽  
The Right ◽  
Coarse To Fine

Abstract A technique for calibrating digital cameras for stereo photogrammetry of cumulus clouds is presented. It has been applied to characterize the formation of summer thunderstorms observed during the Cumulus Photogrammetric, In Situ, and Doppler Observations (CuPIDO) project. Starting from gross measurements of locations, orientations of cameras, and landmark surveys, accurate locations and orientations of the cameras are obtained by minimizing a geometric error (GE). Once accurate camera parameters are obtained, 3D positions of cloud-feature points are computed by triangulation. The main contributions of this paper are as follows. First, it is proven that the GE has only one minimum in the neighborhood of the real parameters of a camera. In other words, searching the minimum of the GE enables the authors to find the right camera parameters even if there are significant differences between the initial measurements and their true values. Second, a new coarse-to-fine iterative algorithm is developed that minimizes the GE and finds the camera parameters. Numerical experiments show that the coarse-to-fine algorithm is efficient and effective. Third, a new landmark survey based on a geographic information system (GIS) rather than field measurements is presented. The GIS landmark survey is an effective and efficient way to obtain landmark world coordinates for camera calibrations in these experiments. Validation of this technique is achieved by the data collected by a NASA/Earth Observing System satellite and an instrumented aircraft. This paper builds on previous research and details the calibration and 3D reconstructions.

An Integrated Approach With Innovative NDTS for Thermal Barrier Coating Assessment: Optical and Frequency Scanning Eddy Current Testing (F-SECT) Combination With Pulsed Thermography

2006 ◽  
Author(s):  
Claudia Rinaldi ◽  
Letizia de Maria ◽  
Federico Cernuschi ◽  
Giampiero Antonelli
Keyword(s):  
Eddy Current ◽  
Gas Turbines ◽  
Current System ◽  
Field Measurements ◽  
Integrated Approach ◽  
Ceramic Coatings ◽  
Thermal Barrier ◽  
Pulsed Thermography ◽  
Damage Level ◽  
The Right

The components of the hot gas path in gas turbines can survive to very high temperatures because they are protected by ceramic Thermal Barrier Coatings (TBC); the failure of such coatings can dramatically reduce the component life. A reliable assessment of the Coating integrity and/or an Incipient TBC Damage Detection can help both in optimising the inspection intervals and in finding the appropriate remedial actions. In this paper the potential of three different NDT techniques applicable to the metallo/ceramic coatings of hot parts are discussed in the light of both results obtained on laboratory aged specimens and in field measurements on operated components. An investigation of the NDTs capability to detect damage evolution was performed on thermal-cycled specimens coated with TBC (both EB-PVD and pseudocolumnar APS) by means of an F-SECT eddy current system, by an innovative portable Piezospectroscopic system and by pulsed thermography. The observation of metallographic sections of the thermal cycled specimens allowed to give the right interpretation to the results of each NDT methodology and enlightened its specific characteristics and potentiality. Moreover in field applicability is discussed for each technique. Finally it is shown how an integrated approach of suitable coating evolution models and complimentary NDT techniques can provide an interesting assessment of the damage level of the metallo/ceramic coatings of operated rotating blades.

Design Gap Acceptance for Right-Turning Vehicles Based on Vehicle Acceleration Capabilities

2015 ◽  
Vol 2521 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Essam Dabbour
Keyword(s):  
Regression Models ◽  
Field Measurements ◽  
Data Logger ◽  
Sight Distance ◽  
Design Guide ◽  
Traffic Stream ◽  
Cross Traffic ◽  
Vehicle Acceleration ◽  
The Cross ◽  
The Right

The current geometric design guide provides a methodology to analyze intersection sight distance for right-turning vehicles at signalized and two-way stop-controlled intersections based on the gaps accepted by the majority of drivers as measured from the field. That methodology is based mainly on driver behavior without considering the actual capabilities of the turning vehicle when accelerating from rest to the speed of the cross-traffic stream. This paper introduced the new design gap concept, which was based on the actual distance and time needed for the turning vehicle to accelerate to the same speed of the cross-traffic stream to avoid a collision. The acceleration capabilities of the turning vehicle were based on field measurements collected by GPS data logger devices that recorded the positions and instantaneous speeds of different turning vehicles at 1-s intervals; based on that, regression models were developed to establish an acceleration profile for a typical vehicle turning to the right from rest. Design tables were provided to help road designers select appropriate design gaps needed for different design speeds and grades of the crossing roadways. In comparison to the new design gaps, the measured gaps used in design were found to be generally inadequate. After implementation of the newly developed design gaps, turning drivers will potentially be able to accelerate comfortably without forcing other drivers in the cross-traffic stream to reduce their speeds or to change lanes to avoid colliding with turning vehicles.

scholarly journals EXPLORING THE POTENTIAL OF AERIAL PHOTOGRAMMETRY FOR 3D MODELLING OF HIGH-ALPINE ENVIRONMENTS

2016 ◽  
Vol XL-3/W4 ◽  
pp. 97-103
Author(s):  
K. Legat ◽  
K. Moe ◽  
D. Poli ◽  
E. Bollmannb
Keyword(s):  
Laser Scanning ◽  
Field Measurements ◽  
Special Focus ◽  
Digital Cameras ◽  
Textured Surfaces ◽  
Control Distribution ◽  
Aerial Photogrammetry ◽  
Technological Advances ◽  
User Groups ◽  
Alpine Environments

High-alpine areas are subject to rapid topographic changes, mainly caused by natural processes like glacial retreat and other geomorphological processes, and also due to anthropogenic interventions like construction of slopes and infrastructure in skiing resorts. Consequently, the demand for highly accurate digital terrain models (DTMs) in alpine environments has arisen. Public administrations often have dedicated resources for the regular monitoring of glaciers and natural hazard processes. In case of glaciers, traditional monitoring encompasses in-situ measurements of area and length and the estimation of volume and mass changes. Next to field measurements, data for such monitoring programs can be derived from DTMs and digital ortho photos (DOPs). Skiing resorts, on the other hand, require DTMs as input for planning and – more recently – for RTK-GNSS supported ski-slope grooming. Although different in scope, the demand of both user groups is similar: high-quality and up-to-date terrain data for extended areas often characterised by difficult accessibility and large elevation ranges. <br><br>Over the last two decades, airborne laser scanning (ALS) has replaced photogrammetric approaches as state-of-the-art technology for the acquisition of high-resolution DTMs also in alpine environments. Reasons include the higher productivity compared to (manual) stereo-photogrammetric measurements, canopy-penetration capability, and limitations of photo measurements on sparsely textured surfaces like snow or ice. Nevertheless, the last few years have shown strong technological advances in the field of aerial camera technology, image processing and photogrammetric software which led to new possibilities for image-based DTM generation even in alpine terrain. At Vermessung AVT, an Austrian-based surveying company, and its subsidiary Terra Messflug, very promising results have been achieved for various projects in high-alpine environments, using images acquired by large-format digital cameras of Microsoft’s UltraCam series and the in-house processing chain centred on the Dense-Image-Matching (DIM) software SURE by nFrames. <br><br> This paper reports the work carried out at AVT for the surface- and terrain modelling of several high-alpine areas using DIM- and ALS-based approaches. A special focus is dedicated to the influence of terrain morphology, flight planning, GNSS/IMU measurements, and ground-control distribution in the georeferencing process on the data quality. Based on the very promising results, some general recommendations for aerial photogrammetry processing in high-alpine areas are made to achieve best possible accuracy of the final 3D-, 2.5D- and 2D products.

scholarly journals The History and Continuity of Kuningan Weaving

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Fendi Adiatmono ◽  
Arif Rivai
Keyword(s):  
Cultural History ◽  
Behavior Patterns ◽  
Digital Cameras ◽  
Transmission Method ◽  
The People ◽  
History Of ◽  
The Subject ◽  
The Right ◽  
And Behavior ◽  
Visual History

Human work is influenced by thinking and behavior patterns. Weaving as a result of human culture is no longer something that is considered important. Birth and development have not been comprehensively explored. Kuningan as a weaving region cannot be separated from the problem. Its development stalled during Colonial rule.This research aims to describe the development of weaving as a home industry in terms of cultural history, form of motives and management. This study aims to (1) describe the weaving motif in the Kuningan home industry; and (2) design forms of motifs that are in accordance with the history of Kuningan culture; and (3) suitable management of art applied to the Kuningan area. This research is a qualitative research where the data obtained from observations, interviews, documentation, and participant observations are presented in descriptive form. The instruments in this study were the researchers themselves with guidelines for observation, interviews, and documentation. The tools used in this study are digital cameras and writing equipment. The validity of the data from this paper is obtained by perseverance / regularity of observation and publication of research results. Analysis of the data used in the form of reduction, presentation of data, and conclusion. The results of this study indicate (1) the weaving motifs of home industry production are not in accordance with the development of other textile arts, such as batik. Then the form of the motive produced is the result of interference from outside countries; and (2) Kuningan home industry weaving is not in the right management, as evidenced by the death of the industry in the present.This research uses the theory of visual history and methods of anthropological approaches, forms of aesthetics, and symbols that are relevant to the subject and subject matter of the problem. So, the context that was built to be legitimate, text, oral and visual, both now and past has been used as a reconstruction. The contents of the study and his work aroused community sensitivity in formulating natural and human development constructions. The general objective of this research is the point of awareness, that it creates filters, balance, and makes a counter of global forces that try to make Indonesian society artificial.This research is expected to emit reference needs for public creativity in general. The written phrases are expected to be able to inspire the sensitivity of the people of Indonesia, to further dynamize the transmission method in the construction of the community.

scholarly journals Ultrasonic measurement of blubber thickness in right whales

2020 ◽  
pp. 301-309
Author(s):  
M. J. Moore ◽  
C.A. Miller ◽  
R. Arthur ◽  
W.A. Lange ◽  
K.G. Prada ◽  
...  
Keyword(s):  
Body Condition ◽  
Repeated Measures ◽  
Field Measurements ◽  
The Body ◽  
Acoustic Properties ◽  
Right Whale ◽  
Adult Growth ◽  
Right Whales ◽  
Connective Tissue Sheath ◽  
The Right

The right whale population in the northwestern Atlantic appears to face the risk of extinction: ship and fishing gear trauma are significantmortality factors, but calving rates are also depressed compared to southern right whales. A major factor in calving success in many speciesis body condition. Knowledge of the dynamics of body condition is also important in studies of juvenile and sub-adult growth and seasonalchanges in adults. This paper describes a method to assess body condition in live right whales. To characterise the acoustic properties ofthe blubber/muscle interface we first studied samples of Atlantic white-sided dolphin and right whale in the laboratory. Tissue heterogeneitywas examined grossly and in histological sections. Acoustic echoes were strong from the sub-dermal connective tissue sheath(s). Echostrengths did not appear to vary with lipid content. We then used a 0.5MHz ultrasound transducer on a cantilevered 12m pole to touch theback of surfacing right whales briefly. Multiple laboratory and field measurements on individual animals suggest repeated measures ofblubber thickness at a single location are reasonably consistent. Data will be normalised to both sampling position on the body and to lengthof the animal, estimated by mensuration from stereo video images of the animal during sampling. In this way, using a long-term consistentdatabase of blubber thickness measurements, and catalogued reproductive histories from on-going photographic identification studies, weplan to assess the significance of changing body condition in right whale population dynamics.

scholarly journals Comparison of Deep Learning and Conventional Demosaicing Algorithms for Mastcam Images

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 308 ◽  
Author(s):  
Chiman Kwan ◽  
Bryan Chou ◽  
James Bell III
Keyword(s):  
Deep Learning ◽  
Image Quality Assessment ◽  
Imaging System ◽  
Subjective Evaluation ◽  
Ground Truth ◽  
Assessment Model ◽  
Blue Color ◽  
Digital Cameras ◽  
Bayer Pattern ◽  
The Right

Bayer pattern filters have been used in many commercial digital cameras. In National Aeronautics and Space Administration’s (NASA) mast camera (Mastcam) imaging system, onboard the Mars Science Laboratory (MSL) rover Curiosity, a Bayer pattern filter is being used to capture the RGB (red, green, and blue) color of scenes on Mars. The Mastcam has two cameras: left and right. The right camera has three times better resolution than that of the left. It is well known that demosaicing introduces color and zipper artifacts. Here, we present a comparative study of demosaicing results using conventional and deep learning algorithms. Sixteen left and 15 right Mastcam images were used in our experiments. Due to a lack of ground truth images for Mastcam data from Mars, we compared the various algorithms using a blind image quality assessment model. It was observed that no one algorithm can work the best for all images. In particular, a deep learning-based algorithm worked the best for the right Mastcam images and a conventional algorithm achieved the best results for the left Mastcam images. Moreover, subjective evaluation of five demosaiced Mastcam images was also used to compare the various algorithms.

scholarly journals Neural mechanisms of coarse-to-fine discrimination in the visual cortex

2014 ◽  
Vol 112 (11) ◽  
pp. 2822-2833 ◽  
Author(s):  
Gopathy Purushothaman ◽  
Xin Chen ◽  
Dmitry Yampolsky ◽  
Vivien A. Casagrande
Keyword(s):  
Visual Cortex ◽  
Tuning Curve ◽  
Discrimination Performance ◽  
Neural Mechanisms ◽  
Initial Increase ◽  
Group 2 ◽  
The Right ◽  
Neuronal Groups ◽  
Coarse To Fine ◽  
Group 1

Vision is a dynamic process that refines the spatial scale of analysis over time, as evidenced by a progressive improvement in the ability to detect and discriminate finer details. To understand coarse-to-fine discrimination, we studied the dynamics of spatial frequency (SF) response using reverse correlation in the primary visual cortex (V1) of the primate. In a majority of V1 cells studied, preferred SF either increased monotonically with time ( group 1) or changed nonmonotonically, with an initial increase followed by a decrease ( group 2). Monotonic shift in preferred SF occurred with or without an early suppression at low SFs. Late suppression at high SFs always accompanied nonmonotonic SF dynamics. Bayesian analysis showed that SF discrimination performance and best discriminable SF frequencies changed with time in different ways in the two groups of neurons. In group 1 neurons, SF discrimination performance peaked on both left and right flanks of the SF tuning curve at about the same time. In group 2 neurons, peak discrimination occurred on the right flank (high SFs) later than on the left flank (low SFs). Group 2 neurons were also better discriminators of high SFs. We examined the relationship between the time at which SF discrimination performance peaked on either flank of the SF tuning curve and the corresponding best discriminable SFs in both neuronal groups. This analysis showed that the population best discriminable SF increased with time in V1. These results suggest neural mechanisms for coarse-to-fine discrimination behavior and that this process originates in V1 or earlier.

Adaptations on Physical Performance Characteristics after a 6-Month Specific Training in Rhythmic Gymnasts

2007 ◽  
Vol 22 (1) ◽  
pp. 10-17
Author(s):  
Helen Douda ◽  
Alexandra Avloniti ◽  
Athanasios Kasabalis ◽  
Savvas P Tokmakidis
Keyword(s):  
Training Program ◽  
Physical Performance ◽  
Field Measurements ◽  
Performance Characteristics ◽  
Analysis Of Covariance ◽  
Control Group ◽  
Technical Performance ◽  
Before And After ◽  
The Right ◽  
Rhythmic Gymnasts

This study examined the specific effects of a 6-month training program on the physical performance characteristics of rhythmic gymnastics (RG) athletes. Seventy-one female rhythmic gymnasts and 81 non-gymnasts (total, 152) were divided into four age categories: 8–10 yrs, 11–12 yrs, 13–14 yrs, and 15–17 yrs. Field measurements of speed, muscular strength, jumping ability, explosive power, and flexibility were made before and after a 6-month training program. The analysis of covariance, using as covariate the initial values, indicated that RG athletes attained the best scores in speed (p < 0.001), jumping ability (p < 0.001), and sit-ups (p < 0.001) and were more flexible than the control group in the sit-and-reach test (p < 0.01) and shoulder flexibility measurements (p < 0.001). In addition, gymnasts showed significant progress and obtained the highest scores in the majority of the tests as compared to the control group after 6 months of training. When measuring hip flexibility and leg lifts forward and sideward, gymnasts had better values on the right leg than the left leg. This observation shows the partial use of the right leg as the prevalent working leg as compared to the left leg which is considered the “support” leg during the performance of different exercises. These results reveal the physical performance characteristics of RG gymnasts as well as the specific adaptations attained in strength and flexibility after 6 months of training. Coaches and athletes should be aware of these findings in order to develop and maintain physical abilities sufficient for a successful technical performance in RG.

Detecting Visual Field Progression in Glaucoma – Using the Right Tools for the Job

2013 ◽  
Vol 07 (01) ◽  
pp. 20 ◽  
Author(s):  
Luke J Saunders ◽  
Richard A Russell ◽  
David P Crabb ◽  
◽  
◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Fields ◽  
Field Measurements ◽  
Automated Perimetry ◽  
Standard Automated Perimetry ◽  
Visual Disability ◽  
New Research ◽  
The Right ◽  
Over Time

Monitoring disease progression is at the centre of managing a patient with glaucoma. This article focuses specifically on how visual field measurements from standard automated perimetry (SAP) can be monitored over time. Various options for analysis on the Humphrey and Octopus perimeters are discussed, from summary indices to event and trend-based analyses; their respective merits and flaws evaluated. It is strongly recommended that quantitative analysis methods and software are used in assessing progression, as variability in threshold measurements makes detecting true deterioration non-trivial. Recommendations on the frequency of visual fields that should be taken per year are also discussed. The article concludes by putting the spotlight on new research being undertaken to improve the methods of measuring and predicting progression, as well as relating visual fields to patient visual disability and quality of life.

Extrapolation of Maximum Noise Levels From Near-Field Measurements to Far-Field Positions

2012 ◽  
Author(s):  
Teresa Bravo ◽  
David Ibarra ◽  
Pedro Cobo
Keyword(s):  
Near Field ◽  
Traffic Noise ◽  
Field Measurements ◽  
Acoustic Properties ◽  
Far Field ◽  
Noise Levels ◽  
Suburban Areas ◽  
New Strategy ◽  
Rolling Noise ◽  
The Right

The goal of this work is to propose a new strategy for the attenuation of the traffic noise, which constitutes one of the main sources of acoustic pollution in urban and suburban areas. This strategy is based on the measurement of the noise radiated by each individual vehicle using an electro-acoustic system, composed of two microphones for the acquisition of the engine and of the rolling noise. These microphones have been situated inside the engine hood and close to the right back tire respectively. The signals have been recorded for diesel and petrol engines and through typical urban and suburban courses with different persons. Using this procedure, we aim to characterise the drivers responsible of the highest noise levels producing maximum annoyance. The near-field measurements have been then extrapolated to far field positions using an analytical filter that takes into account absorbing properties of the propagation floor. For the internal signal it has been necessary to characterise the acoustic properties of the engine hood experimentally using an array of microphones surrounding the vehicle. The propagated noise is calculated considering the absorption due to the geometrical divergence, the absorption by the air, and the effect of the propagating surface. The signals extrapolated to the receiver position could be compared with the current normative to propose recommendations concerning noise control actions.

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