XYZ Coordinates Research Articles

Houston16: A stable geodetic reference frame for subsidence and faulting study in the Houston metropolitan area, Texas, U.S.

Houston, Texas, is one of the earliest regions to employ continuous GPS technology for land subsidence monitoring. Currently, there are over 200 permanent GPS stations located in the greater Houston area. The need for a consistent and stable reference frame to precisely interpret local ground deformation has become critically important since the 1990s, because of the significant spreading of subsidence. We have established a stable Houston reference frame, designated Houston16, using publicly available GPS observations (>5 years) from 15 Continuously Operating Reference Stations (CORS) located outside of the greater Houston area. Applications of the reference frame in subsidence and faulting studies are demonstrated in this article. Houston16 is aligned in origin and scale with the International GNSS Reference Frame of 2008 (IGS08). A 7-parameter method was employed to transform the GPS-derived positional time series from IGS08 to Houston16. The primary product of this study is the seven parameters for transforming Earth-Centered-Earth-Fixed XYZ coordinates from IGS08 to Houston16. The frame stability of Houston16 is approximately 1 mm/year. Houston16 will be updated every few years to mitigate degradation of the frame's stability with time and to synchronize with future updates of the IGS reference frame.

Reconstruction of root systems in Cryptomeria japonica using root point coordinates and diameters

We developed simple algorithms for reconstructing tree root system architecture using only the root point coordinate and diameter, which can be systematically obtained without digging up the root systems. Root system architecture (RSA) is strongly related to various root functions of the tree. The aim of this study was to develop a three-dimensional (3D) RSA model using systematically obtained information on root locations and root diameters at the locations. We excavated root systems of Cryptomeria japonica and systematically obtained XYZ coordinates and root diameters using a 10-cm grid. We clarified the patterns of the root point connections and developed a reconstructed root system model. We found that the root diameters farther from the stump centre are smaller. Additionally, we found that the root lengths of the segments running between the base and the connected root point were smaller than those of other root segments, and the inner angle between the base and the stump and between the base and the connected root point was narrower than for the other pairs. The new RSA model developed according to these results had average accuracies of 0.64 and 0.80 for estimates of total volume and length, respectively. The developed model can estimate 3D RSA using only root point data, which can be obtained without digging up root systems. This suggests a wide applicability of this model in root function evaluation.

Exploring Additional Dimensions of Complexity in Inhibitor Design for Serine β-Lactamases: Mechanistic and Intra- and Inter-molecular Chemistry Approaches.

As a bacterial resistance strategy, serine β-lactamases have evolved from cell wall synthesizing enzymes known as penicillin-binding proteins (PBP), by not only covalently binding β-lactam antibiotics but, also acquiring mechanisms of deacylating these antibiotics. This critical deacylation step leads to release of hydrolyzed and inactivated β-lactams, thereby providing resistance for the bacteria against these antibiotics targeting the cell wall. To combat β-lactamase-mediated antibiotic resistance, numerous β-lactamase inhibitors were developed that utilize various strategies to inactivate the β-lactamase. Most of these compounds are “mechanism-based” inhibitors that in some manner mimic the β-lactam substrate, having a carbonyl moiety and a negatively charged carboxyl or sulfate group. These compounds form a covalent adduct with the catalytic serine via an initial acylation step. To increase the life-time of the inhibitory covalent adduct intermediates, a remarkable array of different strategies was employed to improve inhibition potency. Such approaches include post-acylation intra- and intermolecular chemical rearrangements as well as affecting the deacylation water. These approaches transform the inhibitor design process from a 3-dimensional problem (i.e., XYZ coordinates) to one with additional dimensions of complexity as the reaction coordinate and time spent at each chemical state need to be taken into consideration. This review highlights the mechanistic intricacies of the design efforts of the β-lactamase inhibitors which so far have resulted in the development of “two generations” and 5 clinically available inhibitors.

Terrestrial laser scanning in monitoring of anthropogenic objects

Abstract The registered xyz coordinates in the form of a point cloud captured by terrestrial laser scanner and the intensity values (I) assigned to them make it possible to perform geometric and spectral analyses. Comparison of point clouds registered in different time periods requires conversion of the data to a common coordinate system and proper data selection is necessary. Factors like point distribution dependant on the distance between the scanner and the surveyed surface, angle of incidence, tasked scan’s density and intensity value have to be taken into consideration. A prerequisite for running a correct analysis of the obtained point clouds registered during periodic measurements using a laser scanner is the ability to determine the quality and accuracy of the analysed data. The article presents a concept of spectral data adjustment based on geometric analysis of a surface as well as examples of geometric analyses integrating geometric and physical data in one cloud of points: cloud point coordinates, recorded intensity values, and thermal images of an object. The experiments described here show multiple possibilities of usage of terrestrial laser scanning data and display the necessity of using multi-aspect and multi-source analyses in anthropogenic object monitoring. The article presents examples of multisource data analyses with regard to Intensity value correction due to the beam’s incidence angle. The measurements were performed using a Leica Nova MS50 scanning total station, Z+F Imager 5010 scanner and the integrated Z+F T-Cam thermal camera.

Study into Point Cloud Geometric Rigidity and Accuracy of TLS-Based Identification of Geometric Bodies

Capability of obtaining a multimillion point cloud in a very short time has made the Terrestrial Laser Scanning (TLS) a widely used tool in many fields of science and technology. The TLS accuracy matches traditional devices used in land surveying (tacheometry, GNSS – RTK), but like any measurement it is burdened with error which affects the precise identification of objects based on their image in the form of a point cloud. The point’s coordinates are determined indirectly by means of measuring the angles and calculating the time of travel of the electromagnetic wave. Each such component has a measurement error which is translated into the final result. The XYZ coordinates of a measuring point are determined with some uncertainty and the very accuracy of determining these coordinates is reduced as the distance to the instrument increases. The paper presents the results of examination of geometrical stability of a point cloud obtained by means terrestrial laser scanner and accuracy evaluation of solids determined using the cloud. Leica P40 scanner and two different settings of measuring points were used in the tests. The first concept involved placing a few balls in the field and then scanning them from various sides at similar distances. The second part of measurement involved placing balls and scanning them a few times from one side but at varying distances from the instrument to the object. Each measurement encompassed a scan of the object with automatic determination of its position and geometry. The desk studies involved a semiautomatic fitting of solids and measurement of their geometrical elements, and comparison of parameters that determine their geometry and location in space. The differences of measures of geometrical elements of balls and translations vectors of the solids centres indicate the geometrical changes of the point cloud depending on the scanning distance and parameters. The results indicate the changes in the geometry of scanned objects depending on the point cloud quality and distance from the measuring instrument. Varying geometrical dimensions of the same element suggest also that the point cloud does not keep a stable geometry of measured objects.

Door detection in 3D coloured point clouds of indoor environments

Abstract Door detection is becoming an increasingly important subject in building indoor modelling owing to its value in scan-to-BIM processes. This paper presents an original approach that detects open, semi-open and closed doors in 3D laser scanned data of indoor environments. The proposed technique is unique in that it integrates the information regarding both the geometry (i.e. XYZ coordinates) and colour (i.e. RGB or HSV) provided by a calibrated set of 3D laser scanner and a colour camera. In other words, our technique is developed in a 6D-space framework. The geometry-colour integration and other characteristics of our method make it robust to occlusion and variations in colours resulting from varying lighting conditions at each scanning location (e.g. specular highlights) and from different scanning locations. In addition to this paper, the authors also contribute a public dataset of real scenes along with an annotated ground truth. The dataset has varying levels of challenges and will help to assess the performance of new and existing contributions in the field. The approach proposed in this paper is tested against that dataset, yielding encouraging results.

CHARACTERISATION OF INTENSITY VALUES ON TERRESTRIAL LASER SCANNING FOR RECORDING ENHANCEMENT

Abstract. Mapping surveys based on terrestrial laser scanning (TLS) are common nowadays for different purposes such as documentation of cultural heritage assets. The chance to extract relevant information from TLS surveys depends not only on the fast acquisition of XYZ coordinates, but also on the meaningful intensity values of the fired objects. TLS behaviour depends on several known factors such as distance, texture, roughness, colour and albedo. This paper seeks to find out the mathematical relationship between the TLS intensity values and the colorimetric data using a colour chart. In order to do so, objective colour specification based on well-known colour spaces is needed. The approach used here started with scanning a colour chart containing a number of colour patches with known chromatic and reflection characteristics. After several transformations, the results allowed us to characterise the intensity behaviour of a time-of-flight laser scanner. The characterisation of the intensity values are tested indoor on the colour chart and outdoor on an archaeological shelter. Promising results are obtained to enhance the behaviour of the intensity values coming from the TLS.

Amygdala-Cortical Connectivity: Associations with Anxiety, Development, and Threat.

Amygdala-prefrontal cortex (PFC) functional connectivity may be influenced by anxiety and development. A prior study on anxiety found age-specific dysfunction in the ventromedial PFC (vmPFC), but not amygdala, associated with threat-safety discrimination during extinction recall (Britton etal.). However, translational research suggests that amygdala-PFC circuitry mediates responses following learned extinction. Anxiety-related perturbations may emerge in functional connectivity within this circuit during extinction recall tasks. The current report uses data from the prior study to examine how anxiety and development relate to task-dependent amygdala-PFC connectivity. Eighty-two subjects (14 anxious youths, 15 anxious adults, 25 healthy youths, 28 healthy adults) completed an extinction recall task, which directed attention to different aspects of stimuli. Generalized psychophysiological interaction analysis tested whether task-dependent functional connectivity with anatomically defined amygdala seed regions differed across anxiety and age groups. Whole-brain analyses showed significant interactions of anxiety, age, and attention task (i.e., threat appraisal, explicit threat memory, physical discrimination) on left amygdala functional connectivity with the vmPFC and ventral anterior cingulate cortex (Talairach XYZ coordinates: -16, 31, -6 and 1, 36, -4). During threat appraisal and explicit threat memory (vs. physical discrimination), anxious youth showed more negative amygdala-PFC coupling, whereas anxious adults showed more positive coupling. In the context of extinction recall, anxious youths and adults manifested opposite directions of amygdala-vmPFC coupling, specifically when appraising and explicitly remembering previously learned threat. Future research on anxiety should consider associations of both development and attention to threat with functional connectivity perturbations.

A novel bundle adjustment method with additional ground control point constraint

ABSTRACTBundle adjustment (BA) using parallax angle feature parameterization (ParallaxBA), has been recently reported to have better convergence and more accurate structure estimation in. However, ParallaxBA is a merely free-net BA model and is incapable of geolocating tie points in the global (geodetic) coordinate system. This study presents a novel BA method that incorporates Ground Control Points (GCPs) into ParallaxBA based on hybrid feature parameterization (ParallaxBA-GCP). Different from other BA methods based on feature parameterization using Euclidean xyz coordinates, the tie points in ParallaxBA are parameterized with three types of angles: azimuth, elevation and parallax angles. Therefore, the observation function of the tie points and that of GCPs were described with hybrid feature parameterization in the form of angles and xyz parameterization, respectively. The result of one real data set demonstrates that, when a poor initialization is given, ParallaxBA-GCP can converge within a very few iterations and rapidly triangulate high-quality tie points that satisfies the accuracy requirement of the aerial triangulation.

MreB Senses Local Gaussian Curvature to Pattern Rod-Like Growth of the Bacterial Cell Wall

Over the past few years we have developed an image-processing framework that allows us to extract precise 3D shapes of bacterial cells from fluorescence microscopy data. This active mesh approach minimizes the difference between an observed Z-stack and model shapes that have been convolved with the experimental point spread function. From these xyz coordinates, we calculate geometric parameters such as local curvatures, surface areas, and the relative enrichment of fluorescent signals. Our fluorescent signal is the concentration of the bacterial actin homolog MreB. We have integrated a fluorescent sandwich fusion of MreB with msfGFP at the native locus. This construct has unperturbed mass-doubling times and a proper rod-like shape.We have previously shown in both two and three dimensions that MreB is enriched at negative curvatures and away from positive curvatures [Ursell et al. PNAS 2014]. Here we show in the straight rod Escherichia coli and the curved rod Caulobacter crescentus that MreB senses local surface curvature and, as a result, helps ensure rod-like growth of the cell. The curvature sensed by Escherchia coli MreB is the Gaussian curvature of the surface, the product of the two principal curvatures. Using MreB point mutants that have altered curvature sensitivities, we are testing the hypothesis that cells straighten deformations by patterning growth at the proper geometry. To stably generate their comma shaped geometry, Caulobacter crescentus have developed ways to overcome this straightening mechanism. The enrichment profile of CcMreB shows a plateau in enrichment at small, positive Gaussian curvature values that depends on the protein crescentin. In addition to its structural role in bending the cell, we propose a mechanism whereby crescentin alters the curvature preference of MreB and allows the stabile propagation of the Caulobacter shape.

Correction of terrestrial LiDAR intensity channel using Oren–Nayar reflectance model: An application to lithological differentiation

Ground-based LiDAR has been traditionally used for surveying purposes via 3D point clouds. In addition to XYZ coordinates, an intensity value is also recorded by LiDAR devices. The intensity of the backscattered signal can be a significant source of information for various applications in geosciences.Previous attempts to account for the scattering of the laser signal are usually modelled using a perfect diffuse reflection. Nevertheless, experience on natural outcrops shows that rock surfaces do not behave as perfect diffuse reflectors. The geometry (or relief) of the scanned surfaces plays a major role in the recorded intensity values.Our study proposes a new terrestrial LiDAR intensity correction, which takes into consideration the range, the incidence angle and the geometry of the scanned surfaces. The proposed correction equation combines the classical radar equation for LiDAR with the bidirectional reflectance distribution function of the Oren–Nayar model. It is based on the idea that the surface geometry can be modelled by a relief of multiple micro-facets. This model is constrained by only one tuning parameter: the standard deviation of the slope angle distribution (σslope) of micro-facets.Firstly, a series of tests have been carried out in laboratory conditions on a 2m2 board covered by black/white matte paper (perfect diffuse reflector) and scanned at different ranges and incidence angles. Secondly, other tests were carried out on rock blocks of different lithologies and surface conditions. Those tests demonstrated that the non-perfect diffuse reflectance of rock surfaces can be practically handled by the proposed correction method.Finally, the intensity correction method was applied to a real case study, with two scans of the carbonate rock outcrop of the Dents-du-Midi (Swiss Alps), to improve the lithological identification for geological mapping purposes. After correction, the intensity values are proportional to the intrinsic material reflectance and are independent from range, incidence angle and scanned surface geometry. The corrected intensity values significantly improve the material differentiation.

A Method of Three-Dimensional Recording of Mandibular Movement Based on Two-Dimensional Image Feature Extraction.

Background and ObjectiveTo develop a real-time recording system based on computer binocular vision and two-dimensional image feature extraction to accurately record mandibular movement in three dimensions.MethodsA computer-based binocular vision device with two digital cameras was used in conjunction with a fixed head retention bracket to track occlusal movement. Software was developed for extracting target spatial coordinates in real time based on two-dimensional image feature recognition. A plaster model of a subject’s upper and lower dentition were made using conventional methods. A mandibular occlusal splint was made on the plaster model, and then the occlusal surface was removed. Temporal denture base resin was used to make a 3-cm handle extending outside the mouth connecting the anterior labial surface of the occlusal splint with a detection target with intersecting lines designed for spatial coordinate extraction. The subject's head was firmly fixed in place, and the occlusal splint was fully seated on the mandibular dentition. The subject was then asked to make various mouth movements while the mandibular movement target locus point set was recorded. Comparisons between the coordinate values and the actual values of the 30 intersections on the detection target were then analyzed using paired t-tests.ResultsThe three-dimensional trajectory curve shapes of the mandibular movements were consistent with the respective subject movements. Mean XYZ coordinate values and paired t-test results were as follows: X axis: -0.0037 ± 0.02953, P = 0.502; Y axis: 0.0037 ± 0.05242, P = 0.704; and Z axis: 0.0007 ± 0.06040, P = 0.952. The t-test result showed that the coordinate values of the 30 cross points were considered statistically no significant. (P<0.05)ConclusionsUse of a real-time recording system of three-dimensional mandibular movement based on computer binocular vision and two-dimensional image feature recognition technology produced a recording accuracy of approximately ± 0.1 mm, and is therefore suitable for clinical application. Certainly, further research is necessary to confirm the clinical applications of the method.

Dynamic Universe Model Predicts the Live Trajectory of New Horizons Satellite Going To Pluto

In this paper, Dynamic Universe Model is used for prediction of trajectory of New Horizons (NH) satellite from 3rd Jan 2009 to 1st Jan 2017, taking trajectory ephemerides data of Jan 1&2, 2009 from NASA’s official web of NH, as basis. The NH web gives data up to 1st Sept 2015 as on 20 Jul 2014. The present calculated data from Dynamic Universe Model is given up to 1st Jan 2017, which is 16 months more than the available data. And further trajectory data also can be calculated. It may please be noted the error percentage in predictions went to a maximum in error percentages (0.24 %, -0.0009 %, -0.05 %) compared with NH web for the same date in XYZ coordinates, where as error percentages started from -0.002%, 0.00016 %, -0.0003 % for XYZ coordinates respectively.

ParallaxBA: bundle adjustment using parallax angle feature parametrization

The main contribution of this paper is a novel feature parametrization based on parallax angles for bundle adjustment (BA) in structure and motion estimation from monocular images. It is demonstrated that under certain conditions, describing feature locations using their Euclidean XYZ coordinates or using inverse depth in BA leads to ill-conditioned normal equations as well as objective functions that have very small gradients with respect to some of the parameters describing feature locations. The proposed parallax angle feature parametrization in BA (ParallaxBA) avoids both of the above problems leading to better convergence properties and more accurate motion and structure estimates. Simulation and experimental datasets are used to demonstrate the impact of different feature parametrizations on BA, and the improved convergence, efficiency and accuracy of the proposed ParallaxBA algorithm when compared with some existing BA packages such as SBA, sSBA and g2o. The C/C++ source code of ParallaxBA is available on OpenSLAM (https://openslam.org/).

Methods for estimating relative accuracy of ALS data.

The data acquired by airborne laser scanning is a set of measurement points with certain XYZ coordinates (the so-called cloud of points), located at places where laser pulses sent by the scanning system are refl ected. The coordinates of these points are determined based on the distance measured from the scanner system to the ground along the predetermined laser beam, and the scanning angle at which the beam is sent. The position and orientation of the scanner during the measurement is determined with the use of the GPS/INS system integrated with the scanner [7]. The coverage of the developed area with data from the ALS is done by executing a fl ight in multiple parallel strips that partly overlap, thus ensuring the continuity of the development. The accuracy of the designated coordinates of ALS points depends on the accuracy of observation (distance, scan angle, position and orientation) and on the mathematical model used to determine the coordinates of these points [2]. In connection with the occurrence of errors in the measurement devices and in the defi nition of the mathematical model, there exist some discrepancy in the data from the adjacent strips in overlapping area. Therefore, in order to improve the position of the measuring points, we use ALS data alignment methods by basing on the adjustment of data from adjacent strips and their best integration in the exterior coordinate system. The use of ALS data for the purposes of subsequent developments, such as the DTM (Digital Terrain Model) and DSM (Digital Surface Model) requires the determination of their accuracy. By measuring the diff erences between the adjacent strips, we can estimate the relative accuracy of the ALS, and by sett ing the position of the examined control objects in the exterior coordinate system independently, we can also estimate their absolute accuracy. However, the specifi c nature of data

A Statistical Overview of Experimentally Defined Anisotropic Displacement Parameters (ADP) Currently Deposited in the RCSB PDB

The potential of X-ray crystallography to provide information for protein dynamics has not yet been extensively investigated. In addition to atom XYZ coordinates, typical PDB files provide the temperature factor, also referred to as isotropic B-factor, which describes the magnitude of atomic fluctuations. Currently, approximately 5% (∼5500 unique pdb files) of the structures deposited in the RCSB PDB are high resolution (< 1.4 A). These high resolution structures generally provide an additional line for each atom entry, with the second containing a symmetric tensor with six integers that describes an ellipsoidal, instead of spherical, distribution of electron densities. Importantly, this asymmetric distribution of electron density reflects the anisotropic movement of the atomic nuclei. A diagonalization of this 3x3 tensor yields three eigenvalues (W1, W2, and W3), which define the distribution of electron density along those three prominent axes. The degree of anisotropy is defined as the ratio of W1 to W3 and varies between 0 (extremely anisotropic, like a rod or a pancake) and 1 (a sphere). Our preliminary analysis over the ADPs derived from ∼1500 high resolution structures revealed that interestingly, the backbone carbon atoms are more anisotropic than the C-α and C-β atoms. The C-α atoms show the lowest degree of anisotropy, and proceeding out along the side chain from C-α to C-e, the degree of anisotropy gradually increases. We also analyzed the trend of isotropic B-factors. Indeed, the value of isotropic B-factors increases outward from the backbone C to the C-e atom. In summary, we performed a statistical analysis over the ADPs of structures in the RCSB PDB, with the aim to obtain useful information in order to gain a better understanding of the physical basis of ADP.

Dynamic Universe Model Explains the Variations of Gravitational Deflection Observations of Very-Long-Baseline Interferometry

This paper explains the reasons behind the wide range of values of gravitational deflection (bending) results of Very Long Baseline Interferometry (VLBI) observations, using SITA calculations of Dynamic Universe Model. These higher ranges in VLBI results are beyond explainable values of general relativistic predictions as well as with parameterized post-Newtonian (PPN) formalism, even after accounting for the standard errors. Dynamic Universe model’s built in capabilities of considering simultaneous and dynamic gravitational effect of Sun, planets, local stars etc., makes these discrepancies comprehendible. For doing so, the abilities of Dynamic Universe Model are extended into micro world i.e., the masses of light photons and radio wavelength photons, Neutrinos, electrons and protons etc., by extending from the original mathematical formulation for Dynamic Universe model viz., for planets, stars, Galaxies etc. Later 76 theoretical experiments on grazing radio photons were conducted with different initial xyz coordinates in different directions and with the same status of solar system as on 01.01.2000@00.00:00 hrs, for all these experiments. The resulting bending angles of all these experiments were plotted in a graph against solar elongation angle, which confirms that ‘gravitation of all planets etc.,’ is to be considered as suggested by many researchers for explaining the discrepancies of VLBI observations. This work is a theoretical and computational work and the overall combined results as shown are consolidated in this paper.

Volume Based Measurement of Fabric Drape using Surfer Software and Studies on Effect of Influencing Factors

The human being needs more comfort on clothing than its color, design and appearance. Drape is one of the important factor influencing the aesthetics and comfort of fabrics. In the initial days fabric drape was measured by using Cusick’s drape meter. Due to technology development and up gradation several instruments were developed by many researchers. In this research work one such latest technology was used to measure fabric drape in three dimensional way using SURFER software. Here, the instrument used for measuring fabric drape was slightly modified from the Cusick Drape meter. The perforated circular disc was placed over the sample to measure the xyz coordinates of sample on radials range from 9.5cm to 14.5cm at each 5o intervals. The civil engineers use XYZ coordinates to measure the surface the of land profile (either hill or valley) using software. The same concept was followed to measure the profile of drape in three dimensional way using SURFER software. The xyz values are fed as input to the software and it generates contour lines, 3D view, vector lines, drape volume and drape profile area as output. The drape coefficient was computed from the volume of drape profile and analyzed to study the effect of six different seams, seam directions and number of stitches with two different stitch densities. The seam type, number of stitches (single/double), their interaction density * number of stitches and stitch density * seam have significant effect on volume based drape coefficient. The calculated volume (obtained from average radius and height) is compared with volume generated by SURFER software method and it was found that there is significance difference exists.

Measuring Light and Geometry Data of Roadway Environments with a Camera

Evaluation of the conspicuity of roadway environments for their environmental impact on driving performance is vital for roadway safety. Existing meters and tools for roadway measurements cannot record light and geometry data simultaneously in a high resolution. This study introduced a new method that adopted recently developed high dynamic range (HDR) photogrammetry to measure the luminance and XYZ coordinates of millions of points across a road scene with the same device—a camera, and a MatLab code for data treatment and visualization. To validate this method, the roadway environments of a straight and flat section of Jayhawk Boulevard (482.8 m long) at Lawrence, KS and a roundabout (15.3 m in diameter) at its end were measured under clear and cloudy sky in the daytime and at nighttime with dry and wet pavements. Eight HDR images of the roadway environments under different viewing conditions were generated using the HDR photogrammetric techniques and calibrated. From each HDR image, synchronous light and geometry data were extracted in Radiance and further analyzed to identify potential roadway environmental hazards using the MatLab code (http://people.ku.edu/~h717c996/research.html). The HDR photogrammetric measurement with current equipment had a margin of errors for geometry measurement that varied with the measuring distance, averagely 23.1% - 27.5% for the Jayhawk Boulevard and 9.3% - 16.2% for the roundabout. The accuracy of luminance measurement was proven in the literature as averagely 1.5% - 10.1%. The camera-aided measurement is fast, non-contact, non-destructive, and off the road, thus, it is deemed more efficient and safer than conventional ways using meters and tools. The HDR photogrammetric techniques with current equipment still need improvements on accuracy and speed of the data treatment.

High dynamic range photogrammetry for synchronous luminance and geometry measurement

This study developed high dynamic range photogrammetry for synchronous acquisition of luminance of targets across a scene and their three dimensional coordinates XYZ in the field. The high dynamic range photogrammetry deploys a single digital camera. A Canon Rebel T2i fitted with four Sigma lenses was used and calibrated in a laboratory. Photogrammetric coordinates, transformation equations, two lens radial distortion models, a 3D angular measurement tripod head mounted on a portable platform, and a measurement protocol were developed. The high dynamic range photogrammetry was validated in a laboratory experiment. The average errors of 1.8– 6.2% for luminance mapping seven grey checkers and 12.9–24.3 mm for measuring their XYZ coordinates are deemed acceptable in practice. The high dynamic range photogrammetry would supplement light and geometry measurement and stimulate many applications.