bluuebunny/crossref_metadata_2025 huggingface dataset:
CALIBRATION OF THE SR4500 TIME-OF-FLIGHT CAMERA FOR OUTDOOR MOBILE SURVEYING APPLICATIONS: A CASE STUDY
Authors: Heinkelé C. , Labbé M. , Muzet V. , Charbonnier P.
Published: August 2016

3D-cameras based on Time-of-Flight (ToF) technology have recently raised up to a commercial level of development. In this contribution, we investigate the outdoor calibration and measurement capabilities of the SR4500 ToF camera. The proposed calibration method combines up-to-date techniques with robust estimation. First, intrinsic camera parameters are estimated, which allows converting radial distances into orthogonal ones. The latter are then calibrated using successive acquisitions of a plane at different camera positions, measured by tacheometric techniques. This distance calibration step estimates two coefficient matrices for each pixel, using linear regression. Experimental assessments carried out with a 3D laser-cloud after converting all the data in a common basis show that the obtained precision is twice better than with the constructor default calibration, with a full-frame accuracy of about 4 cm. Moreover, estimating the internal calibration in sunny and warm outdoor conditions yields almost the same coefficients as indoors. Finally, a test shows the feasibility of dynamic outdoor acquisitions and measurements.
STUDY ON IMPROVEMENT OF ACCURACY IN INERTIAL PHOTOGRAMMETRY BY COMBINING IMAGES WITH INERTIAL MEASUREMENT UNIT
Authors: Kawasaki Hideaki , Anzai Shojiro , Koizumi Toshio
Published: August 2016

Inertial photogrammetry is defined as photogrammetry that involves using a camera on which an inertial measurement unit (IMU) is mounted. In inertial photogrammetry, the position and inclination of a shooting camera are calculated using the IMU. An IMU is characterized by error growth caused by time accumulation because acceleration is integrated with respect to time.

 This study examines the procedure to estimate the position of the camera accurately while shooting using the IMU and the structure from motion (SfM) technology, which is applied in many fields, such as computer vision.

 When neither the coordinates of the position of the camera nor those of feature points are known, SfM provides a similar positional relationship between the position of the camera and feature points. Therefore, the actual length of positional coordinates is not determined. If the actual length of the position of the camera is unknown, the camera acceleration is obtained by calculating the second order differential of the position of the camera, with respect to the shooting time. The authors had determined the actual length by assigning the position of IMU to the SfM-calculated position. Hence, accuracy decreased because of the error growth, which was the characteristic feature of IMU. In order to solve this problem, a new calculation method was proposed. Using this method, the difference between the IMU-calculated acceleration and the camera-calculated acceleration can be obtained using the method of least squares, and the magnification required for calculating the actual dimension from the position of the camera can be obtained. The actual length can be calculated by multiplying all the SfM point groups by the obtained magnification factor. This calculation method suppresses the error growth, which is due to the time accumulation in IMU, and improves the accuracy of inertial photogrammetry.
EXPERIMENTAL ASSESSMENT OF THE QUANERGY M8 LIDAR SENSOR
Authors: Mitteta M.-A. , Nouira H. , Roynard X. , Goulette F. , Deschaud J.-E.
Published: August 2016

In this paper, some experiments with the Quanergy M8 scanning LIDAR system are related. The distance measurement obtained with the Quanergy M8 can be influenced by different factors. Moreover, measurement errors can originate from different sources. The environment in which the measurements are performed has an influence (temperature, light, humidity, etc.). Errors can also arise from the system itself. Then, it is necessary to determine the influence of these parameters on the quality of the distance measurements. For this purpose different studies are presented and analyzed. First, we studied the temporal stability of the sensor by analyzing observations during time. Secondly, the assessment of the distance measurement quality has been conducted. The aim of this step is to detect systematic errors in measurements regarding the range. Differents series of measurements have been conducted : at different range and in diffrent conditions (indoor and outdoor). Finally, we studied the consistency between the differents beam of the LIDAR.
DEVELOPMENT AND EVALUATION OF SIMPLE MEASUREMENT SYSTEM USING THE OBLIQUE PHOTO AND DEM
Authors: Nonaka H. , Sasaki H. , Fujimaki S. , Naruke S. , Kishimoto H.
Published: August 2016

When a disaster occurs, we must grasp and evaluate its damage as soon as possible. Then we try to estimate them from some kind of photographs, such as surveillance camera imagery, satellite imagery, photographs taken from a helicopter and so on. Especially in initial stage, estimation of decent damage situation for a short time is more important than investigation of damage situation for a long time.

 One of the source of damage situation is the image taken by surveillance camera, satellite sensor and helicopter. If we can measure any targets in these imagery, we can estimate a length of a lava flow, a reach of a cinder and a sediment volume in volcanic eruption or landslide.

 Therefore in order to measure various information for a short time, we developed a simplified measurement system which uses these photographs. This system requires DEM in addition to photographs, but it is possible to use previously acquired DEM. To measure an object, we require only two steps. One is the determination of the position and the posture in which the photograph is shot. We determine these parameters using DEM. The other step is the measurement of an object in photograph.

 In this paper, we describe this system and show the experimental results to evaluate this system. In this experiment we measured the top of Mt. Usu by using two measurement method of this system. Then we can measure it about one hour and the difference between the measurement results and the airborne LiDAR data are less than 10 meter.
AN EMPRICAL POINT ERROR MODEL FOR TLS DERIVED POINT CLOUDS
Authors: Ozendi Mustafa , Akca Devrim , Topan Hüseyin
Published: August 2016

The random error pattern of point clouds has significant effect on the quality of final 3D model. The magnitude and distribution of random errors should be modelled numerically. This work aims at developing such an anisotropic point error model, specifically for the terrestrial laser scanner (TLS) acquired 3D point clouds. A priori precisions of basic TLS observations, which are the range, horizontal angle and vertical angle, are determined by predefined and practical measurement configurations, performed at real-world test environments. A priori precision of horizontal (𝜎𝜃) and vertical (𝜎𝛼) angles are constant for each point of a data set, and can directly be determined through the repetitive scanning of the same environment. In our practical tests, precisions of the horizontal and vertical angles were found as 𝜎𝜃=±36.6𝑐𝑐 and 𝜎𝛼=±17.8𝑐𝑐, respectively. On the other hand, a priori precision of the range observation (𝜎𝜌) is assumed to be a function of range, incidence angle of the incoming laser ray, and reflectivity of object surface. Hence, it is a variable, and computed for each point individually by employing an empirically developed formula varying as 𝜎𝜌=±2−12 𝑚𝑚 for a FARO Focus X330 laser scanner. This procedure was followed by the computation of error ellipsoids of each point using the law of variance-covariance propagation. The direction and size of the error ellipsoids were computed by the principal components transformation. The usability and feasibility of the model was investigated in real world scenarios. These investigations validated the suitability and practicality of the proposed method.
DEVELOPMENT OF A NOVEL SYSTEM TO MEASURE A CLEARANCE OF A PASSENGER PLATFORM
Authors: Shimizu M. , Oizumi J. , Matsuoka R. , Takeda H. , Okukura H. , Ooya A. , Koike A.
Published: August 2016

Clearances of a passenger platform at a railway station should be appropriately maintained for safety of both trains and passengers. In most Japanese railways clearances between a platform and a train car is measured precisely once or twice a year. Because current measurement systems operate on a track, the closure of the track is unavoidable. Since the procedure of the closure of a track is time-consuming and bothersome, we decided to develop a new system to measure clearances without the closure of a track. A new system is required to work on a platform and the required measurement accuracy is less than several millimetres. We have adopted a 3D laser scanner and stop-and-go operation for a new system. The current systems on a track measure clearances continuously at walking speed, while our system on a platform measures clearances at approximately ten metres intervals. The scanner controlled by a PC acquires a set of point data at each measuring station. Edge points of the platform, top and side points of two rails are detected from the acquired point data. Finally clearances of the platform are calculated by using the detected feature points of the platform and the rails. The results of an experiment using a prototype of our system show that the measurement accuracy by our system would be satisfactory, but our system would take more time than the current systems. Since our system requires no closure of a track, we conclude that our system would be convenient and effective.
ENHANCEMENT OF STEREO IMAGERY BY ARTIFICIAL TEXTURE PROJECTION GENERATED USING A LIDAR
Authors: Veitch-Michaelis Joshua , Muller Jan-Peter , Walton David , Storey Jonathan , Foster Michael , Crutchley Benjamin
Published: August 2016

Passive stereo imaging is capable of producing dense 3D data, but image matching algorithms generally perform poorly on images with large regions of homogenous texture due to ambiguous match costs. Stereo systems can be augmented with an additional light source that can project some form of unique texture onto surfaces in the scene. Methods include structured light, laser projection through diffractive optical elements, data projectors and laser speckle. Pattern projection using lasers has the advantage of producing images with a high signal to noise ratio. We have investigated the use of a scanning visible-beam LIDAR to simultaneously provide enhanced texture within the scene and to provide additional opportunities for data fusion in unmatched regions. The use of a LIDAR rather than a laser alone allows us to generate highly accurate ground truth data sets by scanning the scene at high resolution. This is necessary for evaluating different pattern projection schemes. Results from LIDAR generated random dots are presented and compared to other texture projection techniques. Finally, we investigate the use of image texture analysis to intelligently project texture where it is required while exploiting the texture available in the ambient light image.
AUTOMATIC RAILWAY POWER LINE EXTRACTION USING MOBILE LASER SCANNING DATA
Authors: Zhang Shanxin , Wang Cheng , Yang Zhuang , Chen Yiping , Li Jonathan
Published: August 2016

Research on power line extraction technology using mobile laser point clouds has important practical significance on railway power lines patrol work. In this paper, we presents a new method for automatic extracting railway power line from MLS (Mobile Laser Scanning) data. Firstly, according to the spatial structure characteristics of power-line and trajectory, the significant data is segmented piecewise. Then, use the self-adaptive space region growing method to extract power lines parallel with rails. Finally use PCA (Principal Components Analysis) combine with information entropy theory method to judge a section of the power line whether is junction or not and which type of junction it belongs to. The least squares fitting algorithm is introduced to model the power line. An evaluation of the proposed method over a complicated railway point clouds acquired by a RIEGL VMX450 MLS system shows that the proposed method is promising.
TREE STEM RECONSTRUCTION USING VERTICAL FISHEYE IMAGES: A PRELIMINARY STUDY
Authors: Berveglieri A. , Tommaselli A. M. G.
Published: August 2016

A preliminary study was conducted to assess a tree stem reconstruction technique with panoramic images taken with fisheye lenses. The concept is similar to the Structure from Motion (SfM) technique, but the acquisition and data preparation rely on fisheye cameras to generate a vertical image sequence with height variations of the camera station. Each vertical image is rectified to four vertical planes, producing horizontal lateral views. The stems in the lateral view are rectified to the same scale in the image sequence to facilitate image matching. Using bundle adjustment, the stems are reconstructed, enabling later measurement and extraction of several attributes. The 3D reconstruction was performed with the proposed technique and compared with SfM. The preliminary results showed that the stems were correctly reconstructed by using the lateral virtual images generated from the vertical fisheye images and with the advantage of using fewer images and taken from one single station.
ROBUST VISION-BASED POSE ESTIMATION ALGORITHM FOR AN UAV WITH KNOWN GRAVITY VECTOR
Authors: Kniaz V. V.
Published: August 2016

Accurate estimation of camera external orientation with respect to a known object is one of the central problems in photogrammetry and computer vision. In recent years this problem is gaining an increasing attention in the field of UAV autonomous flight. Such application requires a real-time performance and robustness of the external orientation estimation algorithm. The accuracy of the solution is strongly dependent on the number of reference points visible on the given image. The problem only has an analytical solution if 3 or more reference points are visible. However, in limited visibility conditions it is often needed to perform external orientation with only 2 visible reference points. In such case the solution could be found if the gravity vector direction in the camera coordinate system is known. A number of algorithms for external orientation estimation for the case of 2 known reference points and a gravity vector were developed to date. Most of these algorithms provide analytical solution in the form of polynomial equation that is subject to large errors in the case of complex reference points configurations. This paper is focused on the development of a new computationally effective and robust algorithm for external orientation based on positions of 2 known reference points and a gravity vector. The algorithm implementation for guidance of a Parrot AR.Drone 2.0 micro-UAV is discussed. The experimental evaluation of the algorithm proved its computational efficiency and robustness against errors in reference points positions and complex configurations.
DEVELOPMENT OF IMAGE SELECTION METHOD USING GRAPH CUTS
Authors: Fuse T. , Harada R.
Published: August 2016

3D models have been widely used by spread of many available free-software. Additionally, enormous images can be easily acquired, and images are utilized for creating the 3D models recently. The creation of 3D models by using huge amount of images, however, takes a lot of time and effort, and then efficiency for 3D measurement are required. In the efficient strategy, the accuracy of the measurement is also required. This paper develops an image selection method based on network design that means surveying network construction. The proposed method uses image connectivity graph. The image connectivity graph consists of nodes and edges. The nodes correspond to images to be used. The edges connected between nodes represent image relationships with costs as accuracies of orientation elements. For the efficiency, the image connectivity graph should be constructed with smaller number of edges. Once the image connectivity graph is built, the image selection problem is regarded as combinatorial optimization problem and the graph cuts technique can be applied. In the process of 3D reconstruction, low quality images and similar images are also extracted and removed. Through the experiments, the significance of the proposed method is confirmed. It implies potential to efficient and accurate 3D measurement.
COMBINATION OF TLS POINT CLOUDS AND 3D DATA FROM KINECT V2 SENSOR TO COMPLETE INDOOR MODELS
Authors: Lachat E. , Landes T. , Grussenmeyer P.
Published: August 2016

The combination of data coming from multiple sensors is more and more applied for remote sensing issues (multi-sensor imagery) but also in cultural heritage or robotics, since it often results in increased robustness and accuracy of the final data. In this paper, the reconstruction of building elements such as window frames or door jambs scanned thanks to a low cost 3D sensor (Kinect v2) is presented. Their combination within a global point cloud of an indoor scene acquired with a terrestrial laser scanner (TLS) is considered. If the added elements acquired with the Kinect sensor enable to reach a better level of detail of the final model, an adapted acquisition protocol may also provide several benefits as for example time gain. The paper aims at analyzing whether the two measurement techniques can be complementary in this context. The limitations encountered during the acquisition and reconstruction steps are also investigated.
A FAST AND ROBUST ALGORITHM FOR ROAD EDGES EXTRACTION FROM LIDAR DATA
Authors: Qiu Kaijin , Sun Kai , Ding Kou , Shu Zhen
Published: August 2016

Fast mapping of roads plays an important role in many geospatial applications, such as infrastructure planning, traffic monitoring, and driver assistance. How to extract various road edges fast and robustly is a challenging task. In this paper, we present a fast and robust algorithm for the automatic road edges extraction from terrestrial mobile LiDAR data. The algorithm is based on a key observation: most roads around edges have difference in elevation and road edges with pavement are seen in two different planes. In our algorithm, we firstly extract a rough plane based on RANSAC algorithm, and then multiple refined planes which only contains pavement are extracted from the rough plane. The road edges are extracted based on these refined planes. In practice, there is a serious problem that the rough and refined planes usually extracted badly due to rough roads and different density of point cloud. To eliminate the influence of rough roads, the technology which is similar with the difference of DSM (digital surface model) and DTM (digital terrain model) is used, and we also propose a method which adjust the point clouds to a similar density to eliminate the influence of different density. Experiments show the validities of the proposed method with multiple datasets (e.g. urban road, highway, and some rural road). We use the same parameters through the experiments and our algorithm can achieve real-time processing speeds.
3D DOCUMENTATION OF 40 KILOMETERS OF HISTORICAL PORTICOES – THE CHALLENGE
Authors: Remondino F. , Gaiani M. , Apollonio F. , Ballabeni A. , Ballabeni M. , Morabito D.
Published: August 2016

In the last years the image-based pipeline for 3D reconstruction purposes has received large interest leading to fully automated methodologies able to process large image datasets and deliver 3D products with a level of detail and precision variable according to the applications. Different open issues still exist, in particular when dealing with the 3D surveying and modeling of large and complex scenarios, like historical porticoes. The paper presents an evaluation of various surveying methods for the geometric documentation of ca 40km of historical porticoes in Bologna (Italy). Finally, terrestrial photogrammetry was chosen as the most flexible and productive technique in order to deliver 3D results in form of colored point clouds or textured 3D meshes accessible on the web. The presented digital products are a complementary material for the final candidature of the porticoes as UNESCO WHS.
AN AUTOMATIC METHOD FOR GEOMETRIC SEGMENTATION OF MASONRY ARCH BRIDGES FOR STRUCTURAL ENGINEERING PURPOSES
Authors: Riveiro B. , DeJong M. , Conde B.
Published: August 2016

Despite the tremendous advantages of the laser scanning technology for the geometric characterization of built constructions, there are important limitations preventing more widespread implementation in the structural engineering domain. Even though the technology provides extensive and accurate information to perform structural assessment and health monitoring, many people are resistant to the technology due to the processing times involved. Thus, new methods that can automatically process LiDAR data and subsequently provide an automatic and organized interpretation are required.

 This paper presents a new method for fully automated point cloud segmentation of masonry arch bridges. The method efficiently creates segmented, spatially related and organized point clouds, which each contain the relevant geometric data for a particular component (pier, arch, spandrel wall, etc.) of the structure. The segmentation procedure comprises a heuristic approach for the separation of different vertical walls, and later image processing tools adapted to voxel structures allows the efficient segmentation of the main structural elements of the bridge. The proposed methodology provides the essential processed data required for structural assessment of masonry arch bridges based on geometric anomalies. The method is validated using a representative sample of masonry arch bridges in Spain.
DRAWING FOR TRAFFIC MARKING USING BIDIRECTIONAL GRADIENT-BASED DETECTION WITH MMS LIDAR INTENSITY
Authors: Takahashi G. , Takeda H. , Nakamura K.
Published: August 2016

Recently, the development of autonomous cars is accelerating on the integration of highly advanced artificial intelligence, which increases demand for a digital map with high accuracy. In particular, traffic markings are required to be precisely digitized since automatic driving utilizes them for position detection. To draw traffic markings, we benefit from Mobile Mapping Systems (MMS) equipped with high-density Laser imaging Detection and Ranging (LiDAR) scanners, which produces large amount of data efficiently with XYZ coordination along with reflectance intensity. Digitizing this data, on the other hand, conventionally has been dependent on human operation, which thus suffers from human errors, subjectivity errors, and low reproductivity. We have tackled this problem by means of automatic extraction of traffic marking, which partially accomplished to draw several traffic markings (G. Takahashi et al., 2014). The key idea of the method was extracting lines using the Hough transform strategically focused on changes in local reflection intensity along scan lines. However, it failed to extract traffic markings properly in a densely marked area, especially when local changing points are close each other.

 In this paper, we propose a bidirectional gradient-based detection method where local changing points are labelled with plus or minus group. Given that each label corresponds to the boundary between traffic markings and background, we can identify traffic markings explicitly, meaning traffic lines are differentiated correctly by the proposed method. As such, our automated method, a highly accurate and non-human-operator-dependent method using bidirectional gradient-based algorithm, can successfully extract traffic lines composed of complex shapes such as a cross walk, resulting in minimizing cost and obtaining highly accurate results.
Toward an Automatic Calibration of Dual Fluoroscopy Imaging Systems
Authors: Al-Durgham Kaleel , Lichti Derek , Kuntze Gregor , Sharma Gulshan , Ronsky Janet
Published: August 2016

High-speed dual fluoroscopy (DF) imaging provides a novel, in-vivo solution to quantify the six-degree-of-freedom skeletal kinematics of humans and animals with sub-millimetre accuracy and high temporal resolution. A rigorous geometric calibration of DF system parameters is essential to ensure precise bony rotation and translation measurements. One way to achieve the system calibration is by performing a bundle adjustment with self-calibration. A first-time bundle adjustment-based system calibration was recently achieved. The system calibration through the bundle adjustment has been shown to be robust, precise, and straightforward. Nevertheless, due to the inherent absence of colour/semantic information in DF images, a significant amount of user input is needed to prepare the image observations for the bundle adjustment. This paper introduces a semi-automated methodology to minimise the amount of user input required to process calibration images and henceforth to facilitate the calibration task. The methodology is optimized for processing images acquired over a custom-made calibration frame with radio-opaque spherical targets. Canny edge detection is used to find distinct structural components of the calibration images. Edge-linking is applied to cluster the edge pixels into unique groups. Principal components analysis is utilized to automatically detect the calibration targets from the groups and to filter out possible outliers. Ellipse fitting is utilized to achieve the spatial measurements as well as to perform quality analysis over the detected targets. Single photo resection is used together with a template matching procedure to establish the image-to-object point correspondence and to simplify target identification. The proposed methodology provided 56,254 identified-targets from 411 images that were used to run a second-time bundle adjustment-based DF system calibration. Compared to a previous fully manual procedure, the proposed methodology has significantly reduced the amount of user input needed for processing the calibration images. In addition, the bundle adjustment calibration has reported a 50% improvement in terms of image observation residuals.
DEFORMATION MONITORING OF RETROFITTED SHORT CONCRETE COLUMNS WITH LASER SENSOR
Authors: Avsar E. Ö. , Celik M. F. , Binbir E. , Arslan A. E. , Çokkeçeci D. , Seker D. Z. , Pala S.
Published: August 2016

This paper presents one of the applications of monitoring mechanical tests carried out in Construction Materials Laboratory of Istanbul Technical University. In Turkey, as in many countries, large amount of existing buildings exposed to seismic hazard, therefore various analytical and experimental studies are being conducted to contribute to the solution of the problem. One of the new generation retrofitting techniques is to strength the structural members by using Fiber Reinforcing Polymer (FRP). This study summarize the results of monitoring of deformations short concrete column samples under the incremental compression load. In this study, result of two rectangular short columns are given. One of them was tested as a reference sample, the other sample were tested after strengthening by PET reinforced polymer composite materials. Besides conventional displacement and strain measurement systems, laser scanning method was used to get three dimensional deformed shape of sample at each selected steps.
BRUTE FORCE MATCHING BETWEEN CAMERA SHOTS AND SYNTHETIC IMAGES FROM POINT CLOUDS
Authors: Boerner R. , Kröhnert M.
Published: August 2016

3D point clouds, acquired by state-of-the-art terrestrial laser scanning techniques (TLS), provide spatial information about accuracies up to several millimetres. Unfortunately, common TLS data has no spectral information about the covered scene. However, the matching of TLS data with images is important for monoplotting purposes and point cloud colouration. Well-established methods solve this issue by matching of close range images and point cloud data by fitting optical camera systems on top of laser scanners or rather using ground control points.

 The approach addressed in this paper aims for the matching of 2D image and 3D point cloud data from a freely moving camera within an environment covered by a large 3D point cloud, e.g. a 3D city model. The key advantage of the free movement affects augmented reality applications or real time measurements. Therefore, a so-called real image, captured by a smartphone camera, has to be matched with a so-called synthetic image which consists of reverse projected 3D point cloud data to a synthetic projection centre whose exterior orientation parameters match the parameters of the image, assuming an ideal distortion free camera.
OPTICAL TRIANGULATION ON INSTATIONARY WATER SURFACES
Authors: Mulsow C. , Maas H.-G. , Hentschel B.
Published: August 2016

The measurement of water surfaces is a key task in the field of experimental hydromechanics. Established techniques are usually gauge-based and often come with a large instrumental effort and a limited spatial resolution. The paper shows a photogrammetric alternative based on the well-known laser light sheet projection technique. While the original approach is limited to surfaces with diffuse reflection properties, the developed technique is capable of measuring dynamically on reflecting instationary surfaces. Contrary to the traditional way, the laser line is not observed on the object. Instead, using the properties of water, the laser light is reflected on to a set of staggered vertical planes. The resulting laser line is observed by a camera and measured by subpixel operators. A calibration based on known still water levels provides the parameters for the translation of image space measurements into water level and gradient determination in dynamic experiments. As a side-effect of the principle of measuring the reflected laser line rather than the projected one, the accuracy can be improved by almost a factor two. In experiments a standard deviation of 0.03 mm for water level changes could be achieved. The measuring rate corresponds to the frame rate of the camera. A complete measuring system is currently under development for the Federal Waterways Engineering and Research Institute (BAW).

 This article shows the basic principle, potential and limitations of the method. Furthermore, several system variants optimised for different requirements are presented. Besides the geometrical models of different levels of complexity, system calibration procedures are described too. The applicability of the techniques and their accuracy potential are shown in several practical tests.
CLOSE RANGE DIGITAL PHOTOGRAMMETRY APPLIED TO TOPOGRAPHY AND LANDSLIDE MEASUREMENTS
Authors: Liu Wen-Cheng , Huang Wei-Che
Published: August 2016

Landslide monitoring is a crucial tool for the prevention of hazards. It is often the only solution for the survey and the early-warning of large landslides cannot be stabilized. The objective of present study is to use a low-cost image system to monitor the active landslides. We adopted the direct linear transformation (DLT) method in close range digital photogrammetry to measure terrain of landslide at the Huoyen Shan, Miaoli of central Taiwan and to compare measured results with e-GPS. The results revealed that the relative error in surface area was approximately 1.7% as comparing the photogrammetry with DLT method and e-GPS measurement. It showed that the close range digital photogrammetry with DLT method had the availability and capability to measure the landslides. The same methodology was then applied to measure the terrain before landslide and after landslide in the study area. The digital terrain model (DTM) was established and then was used to calculate the volume of the terrain before landslide and after landslide. The volume difference before and after landslides was 994.16 m3.
3D MODELLING AND RAPID PROTOTYPING FOR CARDIOVASCULAR SURGICAL PLANNING – TWO CASE STUDIES
Authors: Nocerino E. , Remondino F. , Uccheddu F. , Gallo M. , Gerosa G.
Published: August 2016

In the last years, cardiovascular diagnosis, surgical planning and intervention have taken advantages from 3D modelling and rapid prototyping techniques. The starting data for the whole process is represented by medical imagery, in particular, but not exclusively, computed tomography (CT) or multi-slice CT (MCT) and magnetic resonance imaging (MRI). On the medical imagery, regions of interest, i.e. heart chambers, valves, aorta, coronary vessels, etc., are segmented and converted into 3D models, which can be finally converted in physical replicas through 3D printing procedure. In this work, an overview on modern approaches for automatic and semiautomatic segmentation of medical imagery for 3D surface model generation is provided. The issue of accuracy check of surface models is also addressed, together with the critical aspects of converting digital models into physical replicas through 3D printing techniques. A patient-specific 3D modelling and printing procedure (Figure 1), for surgical planning in case of complex heart diseases was developed. The procedure was applied to two case studies, for which MCT scans of the chest are available. In the article, a detailed description on the implemented patient-specific modelling procedure is provided, along with a general discussion on the potentiality and future developments of personalized 3D modelling and printing for surgical planning and surgeons practice.
PHOTOGRAMMETRIC 3D ACQUISITION AND ANALYSIS OF MEDICAMENTOUS INDUCED PILOMOTOR REFLEX (“GOOSE BUMPS”)
Authors: Schneider D. , Hecht A.
Published: August 2016

In a current study at the University Hospital Dresden, Department of Neurology, the autonomous function of nerve fibres of the human skin is investigated. For this purpose, a specific medicament is applied on a small area of the skin of a test person which results in a local reaction (goose bumps). Based on the extent of the area, where the stimulation of the nerve fibres is visible, it can be concluded how the nerve function of the skin works. The aim of the investigation described in the paper is to generate 3D data of these goose bumps. Therefore, the paper analyses and compares different photogrammetric surface measurement techniques in regard to their suitability for the 3D acquisition of silicone imprints of the human skin. Furthermore, an appropriate processing procedure for analysing the recorded point cloud data is developed and presented. It was experimentally proven that by using (low-cost) photogrammetric techniques medicamentous induced goose bumps can be acquired in three dimensions and can be analysed almost fully automatically from the perspective of medical research questions. The relative accuracy was determined with 1% (RMSE) of the area resp. the volume of an individual goose bump.
MONITORING AND DEFORMATION ANALYSIS OF GROYNES USING TLS AT THE RIVER ELBE
Authors: Tschirschwitz F. , Mechelke K. , Jansch H. , Kersten T. P.
Published: August 2016

To enter the Port of Hamburg, one of Europe’s busiest ports all vessels need to navigate around 145 km along the Elbe river, a tide influenced navigation channel. To protect the Elbe shoreline from erosion and to channel the waterway groynes (rigid hydraulic structures) have been built along the river. In the past years since ca. 2001 there has been a large increase in damage of groynes structural integrity at parts of the German waterways. The reason for this was determined in the ever growing size of container vessels passing by and inducing long periodical primary waves which have such a force that they erode the groynes rock structure. To analyse and improve the groynes structural resistance for vessel-induced long periodical wave loads an in-situ study is carried out at Juelssand, located at the Elbe river estuary. Over a period of two years the change of the geometrical structure of two different groyne shapes is monitored automatically by utilising two terrestrial laser scanners mounted in protective housings, located each on a 12 m high platform. The self-contained monitoring systems perform scanning of the two groynes one to two times a day at low tide, as the structures are fully submerged at high tide. The long-periodical wave loads are also determined using pressure sensors in each groyne. To correlate the captured data with vessel events and analyse the effects, vessel related parameters are recorded utilizing the Automatic Identification System (AIS).

 This paper describes the automated processes for the data acquisition and focusses on the deformation that is calculated using current, extended and new algorithms of the Point Cloud Library. It shows the process chain from the acquisition of raw scan files from an elevated station to the filtering of point cloud, the registration, the calculation of pointwise changes and the aggregation to a grid for later correlation with ship parameters. When working outdoor in all kinds of weather conditions, the processes and equipment need to be robust and account for various cases and situations. This is especially applicable for the algorithms, which need to be adaptable to different scenarios like wet surfaces or snow and unwelcome objects ranging from flotsam to birds sitting on the groyne. At the current stage of the research, deformation in the magnitude of a couple of decimetres is observable. The orientation and location of the deformation is on the seaward side and corresponds to the lower distance of vessels leaving the harbour.
THE CIPA DATABASE FOR SAVING THE HERITAGE OF SYRIA
Authors: Silver Minna , Rinaudo Fulvio , Morezzi Emanuele , Quenda Francesca , Moretti Maria Laura
Published: August 2016

CIPA is contributing with its technical knowledge in saving the heritage of Syria by constructing an open access database based on the data that the CIPA members have collected during various projects in Syria over the years before the civil war in the country broke out in 2011. In this way we wish to support the protection and preservation of the environment, sites, monuments, and artefacts and the memory of the cultural region that has been crucial for the human past and the emergence of civilizations. Apart from the countless human atrocities and loss, damage, destruction and looting of the cultural heritage have taken place in a large scale. The CIPA’s initiative is one of the various international projects that have been set up after the conflict started. The Directorate-General of the Antiquities and Museums (DGAM) of Syria as well as UNESCO with its various sub-organizations have been central in facing the challenges during the war. Digital data capture, storage, use and dissemination are in the heart of CIPA’s strategies in recording and documenting cultural heritage, also in Syria. It goes without saying that for the conservation and restoration work the high quality data providing metric information is of utmost importance.
3D VISUALIZATION FOR VIRTUAL MUSEUM DEVELOPMENT
Authors: Skamantzari M. , Georgopoulos A.
Published: August 2016

The interest in the development of virtual museums is nowadays rising rapidly. During the last decades there have been numerous efforts concerning the 3D digitization of cultural heritage and the development of virtual museums, digital libraries and serious games. The realistic result has always been the main concern and a real challenge when it comes to 3D modelling of monuments, artifacts and especially sculptures. This paper implements, investigates and evaluates the results of the photogrammetric methods and 3D surveys that were used for the development of a virtual museum. Moreover, the decisions, the actions, the methodology and the main elements that this kind of application should include and take into consideration are described and analysed. It is believed that the outcomes of this application will be useful to researchers who are planning to develop and further improve the attempts made on virtual museums and mass production of 3D models.
NATIONWIDE NATURAL RESOURCE INVENTORY OF THE PHILIPPINES USING LIDAR: STRATEGIES, PROGRESS, AND CHALLENGES
Authors: Blanco A. C. , Tamondong A. , Perez A. M. , Ang M. R. C. , Paringit E. , Alberto R. , Alibuyog N. , Aquino D. , Ballado A. , Garcia P. , Japitana M. , Ignacio M. T. , Macandog D. , Novero A. , Otadoy R. E. , Regis E. , Rodriguez M. , Silapan J. , Villar R.
Published: August 2016

The Philippines has embarked on a detailed nationwide natural resource inventory using LiDAR through the Phil-LiDAR 2 Program. This 3-year program has developed and has been implementing mapping methodologies and protocols to produce high-resolution maps of agricultural, forest, coastal marine, hydrological features, and renewable energy resources. The Program has adopted strategies on system and process development, capacity building and enhancement, and expanding the network of collaborations. These strategies include training programs (on point cloud and image processing, GIS, and field surveys), workshops, forums, and colloquiums (program-wide, cluster-based, and project-based), and collaboration with partner national government agencies and other organizations. In place is a cycle of training, implementation, and feedback in order to continually improve the system and processes. To date, the Program has achieved progress in the development of workflows and in rolling out products such as resource maps and GIS data layers, which are indispensable in planning and decision-making. Challenges remains in speeding up output production (including quality checks) and in ensuring sustainability considering the short duration of the program. Enhancements in the workflows and protocols have been incorporated to address data quality and data availability issues. More trainings have been conducted for project staff hired to address human resource gaps. Collaborative arrangements with more partners are being established. To attain sustainability, the Program is developing and instituting a system of training, data updating and sharing, information utilization, and feedback. This requires collaboration and cooperation of the government agencies, LGUs, universities, other organizations, and the communities.
UAV AERIAL SURVEY: ACCURACY ESTIMATION FOR AUTOMATICALLY GENERATED DENSE DIGITAL SURFACE MODEL AND ORTHOTHOTO PLAN
Authors: Altyntsev M. A. , Arbuzov S. A. , Popov R. A. , Tsoi G. V. , Gromov M. O.
Published: August 2016

A dense digital surface model is one of the products generated by using UAV aerial survey data. Today more and more specialized software are supplied with modules for generating such kind of models. The procedure for dense digital model generation can be completely or partly automated. Due to the lack of reliable criterion of accuracy estimation it is rather complicated to judge the generation validity of such models. One of such criterion can be mobile laser scanning data as a source for the detailed accuracy estimation of the dense digital surface model generation. These data may be also used to estimate the accuracy of digital orthophoto plans created by using UAV aerial survey data. The results of accuracy estimation for both kinds of products are presented in the paper.
PRELAUNCH PHOTOGRAMMETRIC CALIBRATION OF RUSSIAN SATELLITE ELEKTRO-L IMAGERY INSTRUMENTS
Authors: Gektin U. M. , Egoshkin N. A. , Eremeev V. V. , Kuznetcov A. E. , Kochergin A. M.
Published: August 2016

Technology of prelaunch geometric calibration of multispectral imagery instruments of Russian geostationary satellites “Elektro-L” No.1 and No.2 is considered. Circular control points are used as a test field. Its geometrical model is developed to take distortions in the collimator optical system into account. Multiple observations of a test field at different angles is used to cover the full visual field of a geostationary sensor. New algorithm of circular control point detection is developed and adapted to complex geometry of geostationary imagery. It is capable of processing images formed as a set of separate scans. Under calibration, sensor design parameters and also the law of scanning mirror motion are specified. The paper contains results of the technology approval under prelaunch calibration of MSU-GS sensors for geostationary operational meteorological satellites (GOMS) “Elektro-L” No.1 and No.2.
MODELS FOR PHOTOGRAMMETRIC PROCESSING OF INFORMATION FROM “RESOURCE-P” SATELLITES
Authors: Poshekhonov V. , Eremeev V. , Kuznetcov А. , Kochergin A.
Published: August 2016

The present paper provides information about imagery and navigation systems of the Russian high resolution satellites "Resource- P". Models of image geolocation used for photogrammetric processing of information from all types of imagery systems are designed. Design of these models is based on two task solutions: correct processing of the measurement information and geometric calibration of the imagery systems.

 It is shown that for high-precision interior orientation parameters adjustment of the high-resolution "Geoton" instrument the method of self-calibration should be used. The technology of calibration activities is considered. Distinctive features of calibration of the hyperspectral and wide-swath imagery systems are noted. It is represented in the paper that after calibration the root mean square error (RMSE) of measured geodetic coordinates of objects on images do not exceed 10 m.

 Examples of the obtained models practical application for photogrammetric processing of images from “Resource-P” satellites are shown.
MAPPING LANDSLIDES IN LUNAR IMPACT CRATERS USING CHEBYSHEV POLYNOMIALS AND DEM’S
Authors: Yordanov V. , Scaioni M. , Brunetti M. T. , Melis M. T. , Zinzi A. , Giommi P.
Published: August 2016

Geological slope failure processes have been observed on the Moon surface for decades, nevertheless a detailed and exhaustive lunar landslide inventory has not been produced yet. For a preliminary survey, WAC images and DEM maps from LROC at 100 m/pixels have been exploited in combination with the criteria applied by Brunetti et al. (2015) to detect the landslides. These criteria are based on the visual analysis of optical images to recognize mass wasting features. In the literature, Chebyshev polynomials have been applied to interpolate crater cross-sections in order to obtain a parametric characterization useful for classification into different morphological shapes. Here a new implementation of Chebyshev polynomial approximation is proposed, taking into account some statistical testing of the results obtained during Least-squares estimation. The presence of landslides in lunar craters is then investigated by analyzing the absolute values off odd coefficients of estimated Chebyshev polynomials. A case study on the Cassini A crater has demonstrated the key-points of the proposed methodology and outlined the required future development to carry out.
APPLICATION OF THE TERRA MODIS SATELLITE DATA FOR ENVIRONMENTAL MONITORING IN WESTERN SIBERIA
Authors: Yashchenkoa I. G. , Peremitina T. O.
Published: August 2016

Using the MODIS thematic products, the status of vegetation of oil producing areas in Western Siberia for the period 2010-2015 is monitored. An approach for estimating the impact of various factors on the ecology of oil producing areas using the NDVI coefficient and remote sensing data on the status of vegetation is proposed. The approach is tested within four technologically-disturbed lands – four oil fields, Krapivinskoye, Myldzhenskoye, Luginetskoye, and Urmanskoye in Tomsk region. The territory of the Oglatsky Status Nature Reserve of regional importance is investigated as a reference area.