bluuebunny/crossref_metadata_2025 huggingface dataset:
HIGH PERFORMANCE PHOTOGRAMMETRIC PROCESSING ON COMPUTER CLUSTERS
Authors: Adrov V. N. , Drakin M. A. , Sechin A. Y.
Published: August 2012

Abstract. Most cpu consuming tasks in photogrammetric processing can be done in parallel. The algorithms take independent bits as input and produce independent bits as output. The independence of bits comes from the nature of such algorithms since images, stereopairs or small image blocks parts can be processed independently. Many photogrammetric algorithms are fully automatic and do not require human interference. Photogrammetric workstations can perform tie points measurements, DTM calculations, orthophoto construction, mosaicing and many other service operations in parallel using distributed calculations. Distributed calculations save time reducing several days calculations to several hours calculations. Modern trends in computer technology show the increase of cpu cores in workstations, speed increase in local networks, and as a result dropping the price of the supercomputers or computer clusters that can contain hundreds or even thousands of computing nodes. Common distributed processing in DPW is usually targeted for interactive work with a limited number of cpu cores and is not optimized for centralized administration. The bottleneck of common distributed computing in photogrammetry can be in the limited lan throughput and storage performance, since the processing of huge amounts of large raster images is needed.
PLANIALTIMETRIC EVALUATION OF A CARTOSAT-1 STEREO PAIR – CASE STUDY: SÃO SEBASTIÃO, SP, BRAZIL
Authors: Barros R. S. , Cruz C. B. M. , Rabaco L. M. L.
Published: August 2012

Abstract. It is noticed a significant increase in the development of orbital and airborne sensors that enable the extraction of three-dimensional data. So, it's important the increment of studies about the quality of altimetric values derived from these sensors to verify if the improvements implemented in the acquisition of data may influence the results. In this context, as part of a larger project that aims to evaluate the accuracy of various sensors, this work aims to analysis the planialtimetric accuracy of DEM generated from Cartosat-1 stereo pair. The project was developed for an area near the city of São Sebastião, located in the basin of the North Coast of São Paulo state, in Brasil. The relief in this area is very steep, with a predominance of dense forest vegetation, typical of the Atlantic Forest. All points in this assessment have been established in the field, with the use of single frequency (L1) GNSS receivers, through static relative positioning. In this work it was considered the Brazilian standard specifications (PEC, in Portuguese) for classification of cartographic bases. Results may be considered very good and showed that Cartosat-1 orthoimage presents accuracy equivalent to class B for 1:10.000 scale. The DEM presents altimetric accuracy compatible with class A of the 1:25.000 scale. Results obtained are true for this specific area/study case, but may vary in case different scenes or other studies areas are considered.
Reliable and Practical City Map generation at 1:1000 or 1:500 scale based on “Five control points" recification of digitized images
Authors: Ruan W.
Published: August 2012

Abstract. Using high resolution image for making city map by digital rectification is simple.But five control points can correct image deformation precisely and reliable are not easy particular making 1:500 scale street view map. Nowadays, RTK-GPS becomes the definitive mapping instrument to draw 1:1000 scale maps but get some shortages. That are, 1. Operators can’t have an overall impression of the mapping place. 2 Measuring points are separate so that the lines are not natural and smooth. 3. Data transmission may have 0.1 % mistakes which waste time to check and are troublesome. Given method comes as a substitute, which keeps all advantages and use RTK to definite the key points for drawing. Here are three examples for reference. The map size are extremely large and beyond the custom. (area; 60cm×70cm,80cm×180cm, 60cm×200cm) Which without any splices. The interpolation for rectifying is surface splines which were originally developed for interpolation wing deflections of aircraft; Surface splines are a mathematical tool to interpolate a fuction of two variables. It is Base upon the small deflection equation of an infinite plate. The main adtvantages of the surface splines are that the coordinates of the known points needs not be located in a rectangular array and the function may be differentiated to find slopes. (Contributed by Harderand Desmarais 1972)
ORTHORECTIFICATION BY USING GPGPU METHOD
Authors: Sahin H. , Kulur S.
Published: August 2012

Abstract. Thanks to the nature of the graphics processing, the newly released products offer highly parallel processing units with high-memory bandwidth and computational power of more than teraflops per second. The modern GPUs are not only powerful graphic engines but also they are high level parallel programmable processors with very fast computing capabilities and high-memory bandwidth speed compared to central processing units (CPU). Data-parallel computations can be shortly described as mapping data elements to parallel processing threads. The rapid development of GPUs programmability and capabilities attracted the attentions of researchers dealing with complex problems which need high level calculations. This interest has revealed the concepts of “General Purpose Computation on Graphics Processing Units (GPGPU)” and “stream processing”. The graphic processors are powerful hardware which is really cheap and affordable. So the graphic processors became an alternative to computer processors. The graphic chips which were standard application hardware have been transformed into modern, powerful and programmable processors to meet the overall needs. Especially in recent years, the phenomenon of the usage of graphics processing units in general purpose computation has led the researchers and developers to this point. The biggest problem is that the graphics processing units use different programming models unlike current programming methods. Therefore, an efficient GPU programming requires re-coding of the current program algorithm by considering the limitations and the structure of the graphics hardware. Currently, multi-core processors can not be programmed by using traditional programming methods. Event procedure programming method can not be used for programming the multi-core processors. GPUs are especially effective in finding solution for repetition of the computing steps for many data elements when high accuracy is needed. Thus, it provides the computing process more quickly and accurately. Compared to the GPUs, CPUs which perform just one computing in a time according to the flow control are slower in performance. This structure can be evaluated for various applications of computer technology. In this study covers how general purpose parallel programming and computational power of the GPUs can be used in photogrammetric applications especially direct georeferencing. The direct georeferencing algorithm is coded by using GPGPU method and CUDA (Compute Unified Device Architecture) programming language. Results provided by this method were compared with the traditional CPU programming. In the other application the projective rectification is coded by using GPGPU method and CUDA programming language. Sample images of various sizes, as compared to the results of the program were evaluated. GPGPU method can be used especially in repetition of same computations on highly dense data, thus finding the solution quickly.
INFORMATION MANAGEMENT SYSTEMS FOR MONITORING AND DOCUMENTING WORLD HERITAGE - THE SILK ROADS CHRIS
Authors: Vileikis O. , Serruys E. , Dumont B. , van Balen K. , Santana Quinterod M. , de Maeyer P. , Tigny V.
Published: August 2012

Abstract. This paper discusses the application of Information Management Systems (IMS) for documenting and monitoring World Heritage (WH) properties. The application of IMS in WH can support all stakeholders involved in conservation, and management of cultural heritage by more easily inventorying, mining and exchanging information from multiple sources based on international standards. Moreover, IMS could assist in detecting damages and preparing management strategies to mitigate risks, and slowing down the deterioration of the integrity of WH properties. The case study of the Silk Roads Cultural Heritage Resource Information System (CHRIS), a Belgian Federal Science Policy Office funded project, illustrates the capabilities of IMS in the context of the nomination of the Central Asian Silk Roads on the WH List. This multi-lingual, web-based IMS will act as a collaborative platform allowing for the completion of improved transnational nomination dossiers and subsequent monitoring activities with all necessary baseline information to easily verify consistency and quality of the proposal. The Silk Roads CHRIS Geospatial Content Management System uses open source technologies and allows to georeference data from different scales and sources including data from field recording methods and combine it with historical and heritage features documented through various means such as textual descriptions, documents, photographs, 3D models or videos. Moreover, tailored maps can also be generated by overlaying a selection of available layers and then be exported to support the nomination dossier. Finally, by using this innovative information and decision support system, the State Parties and other interested stakeholders will have access to a complete nomination dossier and could therefore respond more effectively to hazards and disaster phenomena.
HIERARCHICAL OPTIMIZATION MODEL ON GEONETWORK
Authors: Zha Z. , Jiang J. , Zhou X.
Published: August 2012

Abstract. In existing construction experience of Spatial Data Infrastructure (SDI), GeoNetwork, as the geographical information integrated solution, is an effective way of building SDI. During GeoNetwork serving as an internet application, several shortcomings are exposed. The first one is that the time consuming of data loading has been considerately increasing with the growth of metadata count. Consequently, the efficiency of query and search service becomes lower. Another problem is that stability and robustness are both ruined since huge amount of metadata. The final flaw is that the requirements of multi-user concurrent accessing based on massive data are not effectively satisfied on the internet. A novel approach, Hierarchical Optimization Model (HOM), is presented to solve the incapability of GeoNetwork working with massive data in this paper. HOM optimizes the GeoNetwork from these aspects: internal procedure, external deployment strategies, etc. This model builds an efficient index for accessing huge metadata and supporting concurrent processes. In this way, the services based on GeoNetwork can maintain stable while running massive metadata. As an experiment, we deployed more than 30 GeoNetwork nodes, and harvest nearly 1.1 million metadata. From the contrast between the HOM-improved software and the original one, the model makes indexing and retrieval processes more quickly and keeps the speed stable on metadata amount increasing. It also shows stable on multi-user concurrent accessing to system services, the experiment achieved good results and proved that our optimization model is efficient and reliable.
INCORPORATING LOAD BALANCING SPATIAL ANALYSIS INTO XML-BASED WEBGIS
Authors: Huang H.
Published: August 2012

Abstract. This article aims to introduce load balancing spatial analysis into XML-based WebGIS. In contrast to other approaches that implement spatial queries and analyses solely on server or browser sides, load balancing spatial analysis carries out spatial analysis on either the server or the browser sides depending on the execution costs (i.e., network transmission costs and computational costs). In this article, key elements of load balancing middlewares are investigated, and relevant solution is proposed. The comparison with server-side solution, browse-side solution, and our former solution shows that the proposed solution can optimize the execution of spatial analysis, greatly ease the network transmission load between the server and the browser sides, and therefore lead to a better performance. The proposed solution enables users to access high-performance spatial analysis simply via a web browser.
PARALLEL AND ADAPTIVE UNIFORM-DISTRIBUTED REGISTRATION METHOD FOR CHANG’E-1 LUNAR REMOTE SENSED IMAGERY
Authors: Ning X. , Hao M.
Published: August 2012

Abstract. On the October 24th 2007, China launched its first Lunar Probe Satellite "Chang'E I". After the 494 days travelling, the probe vehicle landed accurately at its predetermined landing site on the moon at 52.36 degrees east longitude and 1.5 degrees south latitude. It sent back the first imagery of the lunar surface on 26 November 2007 and accomplished all the scheduled scientific tasks successfully. As the first lunar Probe Satellite, the major goal of Chang'E I mission is to obtain three-dimensional images of the landforms and geological structures of the lunar surface, so as to provide a reference for planned future soft landings. However, due to the dramatic change of the radiation information of the CE-1imagery, the traditional methods that are based on the gray and line characters show the limitation achieving a satisfied result. Moreover, the registration processing between lunar images that cover the whole moon has proved to be very time-consuming. To resolve the above-mentioned registration difficulties, a parallel and adaptive uniform-distributed registration method for CE-1 lunar remote sensed imagery is proposed in this paper. Based on 6 pairs of randomly selected images, both the standard SIFT algorithm and the parallel and adaptive uniform-distributed registration method were executed, the versatility and effectiveness were assessed. The experimental results indicate that: by applying the parallel and adaptive uniform-distributed registration method, the efficiency of CE-1 lunar remote sensed imagery registration were increased dramatically. Therefore, the proposed method in the paper could acquire uniform-distributed registration results more effectively, the registration difficulties including difficult to obtain results, time-consuming, non-uniform distribution could be successfully solved.
EVENT-DRIVEN OBSERVATIONS AND COMPREHENSIVE EVALUATION FOR NATURAL DISASTER ASSESSMENT IN CHINA
Authors: Wang Z. , Li Z. , Shen Y. , Wu L. , Li H.
Published: August 2012

Abstract. The Chinese event-driven observations and disaster assessment system is established so as to make information related to environmental risk and vulnerability easily accessible to decision-makers through this centralized platform. At 7:49 AM on April 14, 2010, an earthquake of 7.1 magnitude collapsed buildings in Yushu County, Yushu Tibetan Autonomous Prefecture in Qinghai Province. For emergence response, we presented a method for generating seismic intensity map based on seismological mechanism solutions. The disaster assessment system automatically drew the distribution map of affected population 1 hour after the Yushu earthquake. In the case of distribution map of affected population, we made the judgment that the Gyêgu town maybe the worst hit town in the Yushu earthquake because it is not only near the epicenter, but also the capital of Yushu Tibetan Autonomous Prefecture. Then event-driven observations are taken on Gyêgu town. Referring to usable data, the chains of rapid assessment on earthquake disaster were analyzed, and different models were established for assessing affected population, damaged houses and lifelines and comprehensive earthquake loss evaluation.
PHOTOGRAMMETRY AND REMOTE SENSING: NEW GERMAN STANDARDS (DIN) SETTING QUALITY REQUIREMENTS OF PRODUCTS GENERATED BY DIGITAL CAMERAS, PAN-SHARPENING AND CLASSIFICATION
Authors: Reulke R. , Baltrusch S. , Brunn A. , Komp K. , Kresse W. , von Schönermark M. , Spreckels V.
Published: August 2012

Abstract. 10 years after the first introduction of a digital airborne mapping camera in the ISPRS conference 2000 in Amsterdam, several digital cameras are now available. They are well established in the market and have replaced the analogue camera. A general improvement in image quality accompanied the digital camera development. The signal-to-noise ratio and the dynamic range are significantly better than with the analogue cameras. In addition, digital cameras can be spectrally and radiometrically calibrated. The use of these cameras required a rethinking in many places though. New data products were introduced. In the recent years, some activities took place that should lead to a better understanding of the cameras and the data produced by these cameras. Several projects, like the projects of the German Society for Photogrammetry, Remote Sensing and Geoinformation (DGPF) or EuroSDR (European Spatial Data Research), were conducted to test and compare the performance of the different cameras. In this paper the current DIN (Deutsches Institut fuer Normung - German Institute for Standardization) standards will be presented. These include the standard for digital cameras, the standard for ortho rectification, the standard for classification, and the standard for pan-sharpening. In addition, standards for the derivation of elevation models, the use of Radar / SAR, and image quality are in preparation. The OGC has indicated its interest in participating that development. The OGC has already published specifications in the field of photogrammetry and remote sensing. One goal of joint future work could be to merge these formerly independent developments and the joint development of a suite of implementation specifications for photogrammetry and remote sensing.
MULTI-TEMPORAL ANALYSIS OF LANDSCAPES AND URBAN AREAS
Authors: Nocerino E. , Menna F. , Remondino F.
Published: August 2012

Abstract. This article presents a 4D modelling approach that employs multi-temporal and historical aerial images to derive spatio-temporal information for scenes and landscapes. Such imagery represent a unique data source, which combined with photo interpretation and reality-based 3D reconstruction techniques, can offer a more complete modelling procedure because it adds the fourth dimension of time to 3D geometrical representation and thus, allows urban planners, historians, and others to identify, describe, and analyse changes in individual scenes and buildings as well as across landscapes. Particularly important to this approach are historical aerial photos, which provide data about the past that can be collected, processed, and then integrated as a database. The proposed methodology employs both historical (1945) and more recent (1973 and 2000s) aerial images from the Trentino region in North-eastern Italy in order to create a multi-temporal database of information to assist researchers in many disciplines such as topographic mapping, geology, geography, architecture, and archaeology as they work to reconstruct building phases and to understand landscape transformations (Fig. 1).
DETERMINING THE TECHNICAL STANDARDS OF PING PONG TABLE BY USING CLOSE RANGE PHOTOGRAMMETRY
Authors: Acar U. , Bayram B. , Cetin H. I. , Sanlı F. B.
Published: August 2012

Abstract. In the presented study, quality measurements were made regarding three different ping pong tables that were produced with three different materials. Measurements were made on the purpose of confirming whether the tables can be used as a match table that is in the standard of International Table Tennis Federation or not. For this confirmation, bouncing height of the table tennis ball is measured which is approved by ITTF. Average bouncing height that is required by federation standards is minimum 23 cm for free falling table tennis ball from 30 cm. In order to locate the bounce on the tables, the table tennis ball is released from 30cm in free fall with equipment was. In the meantime, 24 video frames videos were shot with a Full HD (1920 × 1080) camera. Each frame of videos that were taken is separated from each other. Each frame is analyzed and highest bounce is measured. As a result of the study, the bouncing heights of the three tables were measured as 23.04 cm, 23.33 cm, 22.91 cm for table1, for table2 and for table3 respectively.
IMAGING A SUSTAINABLE FUTURE IN 3D
Authors: Schuhr W. , Lee J. D. , Kanngieser E.
Published: August 2012

Abstract. It is the intention of this paper, to contribute to a sustainable future by providing objective object information based on 3D photography as well as promoting 3D photography not only for scientists, but also for amateurs. Due to the presentation of this article by CIPA Task Group 3 on "3D Photographs in Cultural Heritage", the presented samples are masterpieces of historic as well as of current 3D photography concentrating on cultural heritage. In addition to a report on exemplarily access to international archives of 3D photographs, samples for new 3D photographs taken with modern 3D cameras, as well as by means of a ground based high resolution XLITE staff camera and also 3D photographs taken from a captive balloon and the use of civil drone platforms are dealt with. To advise on optimum suited 3D methodology, as well as to catch new trends in 3D, an updated synoptic overview of the 3D visualization technology, even claiming completeness, has been carried out as a result of a systematic survey. In this respect, e.g., today's lasered crystals might be "early bird" products in 3D, which, due to lack in resolution, contrast and color, remember to the stage of the invention of photography.
CO-REGISTRATION OF 3D POINT CLOUDS BY USING AN ERRORS-IN-VARIABLES MODEL
Authors: Aydar U. , Altan M. O. , Akyılmaz O. , Akca D.
Published: August 2012

Abstract. Co-registration of point clouds of partially scanned objects is the first step of the 3D modeling workflow. The aim of co-registration is to merge the overlapping point clouds by estimating the spatial transformation parameters. In the literature, one of the most popular methods is the ICP (Iterative Closest Point) algorithm and its variants. There exist the 3D least squares (LS) matching methods as well. In most of the co-registration methods, the stochastic properties of the search surfaces are usually omitted. This omission is expected to be minor and does not disturb the solution vector significantly. However, the a posteriori covariance matrix will be affected by the neglected uncertainty of the function values. This causes deterioration in the realistic precision estimates. In order to overcome this limitation, we propose a new method where the stochastic properties of both (template and search) surfaces are considered under an errors-in-variables (EIV) model. The experiments have been carried out using a close range laser scanning data set and the results of the conventional and EIV types of the ICP matching methods have been compared.
PERFORMANCE ANALYSIS OF A LOW-COST TRIANGULATION-BASED 3D CAMERA: MICROSOFT KINECT SYSTEM
Authors: Chow J. C .K. , Ang K. D. , Lichti D. D. , Teskey W. F.
Published: August 2012

Abstract. Recent technological advancements have made active imaging sensors popular for 3D modelling and motion tracking. The 3D coordinates of signalised targets are traditionally estimated by matching conjugate points in overlapping images. Current 3D cameras can acquire point clouds at video frame rates from a single exposure station. In the area of 3D cameras, Microsoft and PrimeSense have collaborated and developed an active 3D camera based on the triangulation principle, known as the Kinect system. This off-the-shelf system costs less than $150 USD and has drawn a lot of attention from the robotics, computer vision, and photogrammetry disciplines. In this paper, the prospect of using the Kinect system for precise engineering applications was evaluated. The geometric quality of the Kinect system as a function of the scene (i.e. variation of depth, ambient light conditions, incidence angle, and object reflectivity) and the sensor (i.e. warm-up time and distance averaging) were analysed quantitatively. This system's potential in human body measurements was tested against a laser scanner and 3D range camera. A new calibration model for simultaneously determining the exterior orientation parameters, interior orientation parameters, boresight angles, leverarm, and object space features parameters was developed and the effectiveness of this calibration approach was explored.
A METHOD FOR THE REGISTRATION OF HEMISPHERICAL PHOTOGRAPHS AND TLS INTENSITY IMAGES
Authors: Schmidt A. , Schilling A. , Maas H.-G.
Published: August 2012

Abstract. Terrestrial laser scanners generate dense and accurate 3D point clouds with minimal effort, which represent the geometry of real objects, while image data contains texture information of object surfaces. Based on the complementary characteristics of both data sets, a combination is very appealing for many applications, including forest-related tasks. In the scope of our research project, independent data sets of a plain birch stand have been taken by a full-spherical laser scanner and a hemispherical digital camera. Previously, both kinds of data sets have been considered separately: Individual trees were successfully extracted from large 3D point clouds, and so-called forest inventory parameters could be determined. Additionally, a simplified tree topology representation was retrieved. From hemispherical images, leaf area index (LAI) values, as a very relevant parameter for describing a stand, have been computed. The objective of our approach is to merge a 3D point cloud with image data in a way that RGB values are assigned to each 3D point. So far, segmentation and classification of TLS point clouds in forestry applications was mainly based on geometrical aspects of the data set. However, a 3D point cloud with colour information provides valuable cues exceeding simple statistical evaluation of geometrical object features and thus may facilitate the analysis of the scan data significantly.
DEVELOPMENT OF A WIND OBSERVATION SYSTEM USING PHOTOGRAMMETRY
Authors: Kawasaki H. , Koizumi T. , Matsuda K.
Published: August 2012

Abstract. Quantitative understanding of wind flow near the ground surface in all three dimensions onsite is extremely important for wind research.The objective of this research is to develop a system to quantitatively measure wind flow near the ground surface in both the horizontal and vertical directions (in other words, wind flow in three dimensions) using inertial photographic surveying or phototheodolite. In this method, a balloon (a no-lift balloon) with the same relative weight as air and soap bubbles were released as tracers. Their movements were captured using stereo-photography and single photographs, and then the path of particles was analyzed in three dimensions. For this document, wind flow near tall buildings, conical vortices flow on the rooftops of buildings and wind flow crossing over an embankment were measured. The results of the testing proved that the measurement methods were effective.
DETAILED PRIMITIVE-BASED 3D MODELING OF ARCHITECTURAL ELEMENTS
Authors: Remondino F. , Lo Buglio D. , Nony N. , De Luca L.
Published: August 2012

Abstract. The article describes a pipeline, based on image-data, for the 3D reconstruction of building façades or architectural elements and the successive modeling using geometric primitives. The approach overcome some existing problems in modeling architectural elements and deliver efficient-in-size reality-based textured 3D models useful for metric applications. For the 3D reconstruction, an opensource pipeline developed within the TAPENADE project is employed. In the successive modeling steps, the user manually selects an area containing an architectural element (capital, column, bas-relief, window tympanum, etc.) and then the procedure fits geometric primitives and computes disparity and displacement maps in order to tie visual and geometric information together in a light but detailed 3D model. Examples are reported and commented.
FROM GEOMETRY TO DIAGNOSIS: EXPERIENCES OF GEOMATICS IN STRUCTURAL ENGINEERING
Authors: Riveiro B. , Arias P. , Armesto J. , Caamaño J. C. , Solla M.
Published: August 2012

Abstract. Terrestrial photogrammetry and laser scanning are technologies that have been successfully used for metric surveying and 3D modelling in many different fields (archaeological and architectural documentation, industrial retrofitting, mining, structural monitoring, road surveying, etc.). In the case of structural applications, these techniques have been successfully applied to 3D modelling and sometimes monitoring; but they have not been sufficiently implemented to date, as routine tools in infrastructure management systems, in terms of automation of data processing and integration in the condition assessment procedures. In this context, this paper presents a series of experiences in the usage of terrestrial photogrammetry and laser scanning in the context of dimensional and structural evaluation of structures. These experiences are particularly focused on historical masonry structures, but modern prestressed concrete bridges are also investigated. The development of methodological procedures for data collection, and data integration in some cases, is tackled for each particular structure (with access limitations, geometrical configuration, range of measurement, etc.). The accurate geometrical information provided by both terrestrial techniques motivates the implementation of such results in the complex, and sometimes slightly approximated, geometric scene that is frequently used in structural analysis. In this sense, quantitative evaluating of the influence of real and accurate geometry in structural analysis results must be carried out. As main result in this paper, a series of experiences based on the usage of photogrammetric and laser scanning to structural engineering are presented.
STUDY ON THE LINE SCAN CCD CAMERA CALIBRATION OF VEHICLE-BORNE 3D DATA ACQUISITION SYSTEM
Authors: Han Y. , Yang B. , Zhang F.
Published: August 2012

Abstract. Based on the characters of the line scan CCD camera and the Vehicle-borne 3D data acquisition system, it presented a novel method to calibrate the line Scan Camera (LSC) based on the laser scanner. Using the angle information in the original laser scanner data, combing the principle of the line scan camera, it built a calibration model for LSC and designed some experiment methods to implement that. Using the new model and the special experiment methods it computed out high precision LSC calibration parameters, which provides basis for the fusion of image and point cloud data and gives references to the similar sensors calibration.
INVESTIGATIONS ON A COMBINED RGB / TIME-OF-FLIGHT APPROACH FOR CLOSE RANGE APPLICATIONS
Authors: Hastedt H. , Luhmann Th.
Published: August 2012

Abstract. 3D surface and scene reconstruction for close range applications mainly rely on high resolution and accurate system devices and powerful algorithms. Camera systems based on the time-of-flight principle allow for real-time 3D distance measurements. Unfortunately these devices are limited in resolution and accuracy. But applying calibration models and combining with high-resolution image data offers a promising approach in order to form a multisensor system for close range applications. This article will present investigations on such a multisensor system. Different options on data fusion processing of distance information and high-resolution color information in order to generate dense 2 1/2 D and 3D point clouds will be presented. The multisensor system is calibrated with respect to its interior and exterior orientation. The time-of-flight distance information is optimized extracting best information of different data captures with a set of integration times following the principle of high dynamic range imaging. The high-resolution RGB image information is projected into object space and intersected with the object surface from the time-of-flight camera. First results of this solution on dense monoplotting and its verification will be presented.
The Scanning Photogrammetry
Authors: Ke T. , Zhang Z. X. , Huang S.
Published: August 2012

Abstract. The paper proposes a new photogrammetry method, the scanning photogrammetry, to solve the problem that large targets can hardly be processed as a whole one in close-range photogrammetry. The method enlarges the view angle and intersection angle effectively by rotating camera in horizontal and vertical direction when photographing large targets. Meanwhile, it is a kind of multi-baseline photogrammetry which increases matching reliability and improves the quality and quantity of observations. Besides, in order to acquire images automatically, we develop the photograph scanner which ensures the efficiency and quality of photography. And the scanning photogrammetry system has been successfully used in deformation monitoring of Wumen Circumvallation in the Forbidden City. In the experiments, data is processed automatically by classical triangulation and self-calibration bundle adjustment. The result proves that the precision can meet with the deformation monitoring requirements and data processing efficiency accomplishes to engineering measurement applications.
STUDY ON SHADOW EFFECTS OF VARIOUS FEATURES ON CLOSE RANGE THERMAL IMAGES
Authors: Liao C. L. , Huang H. H.
Published: August 2012

Abstract. Thermal infrared data become more popular in remote sensing investigation, for it could be acquired both in day and night. The change of temperature has special characteristic in natural environment, so the thermal infrared images could be used in monitoring volcanic landform, the urban development, and disaster prevention. Heat shadow is formed by reflecting radiating capacity which followed the objects. Because of poor spatial resolution of thermal infrared images in satellite sensor, shadow effects were usually ignored. This research focus on discussing the shadow effects of various features, which include metals and nonmetallic materials. An area-based thermal sensor, FLIR-T360 was selected to acquire thermal images. Various features with different emissivity were chosen as reflective surface to obtain thermal shadow in normal atmospheric temperature. Experiments found that the shadow effects depend on the distance between sensors and features, depression angle, object temperature and emissivity of reflective surface. The causes of shadow effects have been altered in the experiment for analyzing the variance in thermal infrared images. The result shows that there were quite different impacts by shadow effects between metals and nonmetallic materials. The further research would be produced a math model to describe the shadow effects of different features in the future work.
CALIBRATION AND EPIPOLAR GEOMETRY OF GENERIC HETEROGENOUS CAMERA SYSTEMS
Authors: Luber A. , Rueß D. , Manthey K. , Reulke R.
Published: August 2012

Abstract. The application of perspective camera systems in photogrammetry and computer vision is state of the art. In recent years nonperspective and especially omnidirectional camera systems were increasingly used in close-range photogrammetry tasks. In general perspective camera model, i. e. pinhole model, cannot be applied when using non-perspective camera systems. However, several camera models for different omnidirectional camera systems are proposed in literature. Using different types of cameras in a heterogeneous camera system may lead to an advantageous combination. The advantages of different camera systems, e. g. field of view and resolution, result in a new enhanced camera system. If these different kinds of cameras can be modeled, using a unified camera model, the total calibration process can be simplified. Sometimes it is not possible to give the specific camera model in advance. In these cases a generic approach is helpful. Furthermore, a simple stereo reconstruction becomes possible using a fisheye and a perspective camera for example. In this paper camera models for perspective, wide-angle and omnidirectional camera systems are evaluated. The crucial initialization of the model’s parameters is conducted using a generic method that is independent of the particular camera system. The accuracy of this generic camera calibration approach is evaluated by calibration of a dozen of real camera systems. It will be shown, that a unified method of modeling, parameter approximation and calibration of interior and exterior orientation can be applied to derive 3D object data.
ACCURACY EVALUATION OF STEREO CAMERA SYSTEMS WITH GENERIC CAMERA MODELS
Authors: Rueß D. , Luber A. , Manthey K. , Reulke R.
Published: August 2012

Abstract. In the last decades the consumer and industrial market for non-projective cameras has been growing notably. This has led to the development of camera description models other than the pinhole model and their employment in mostly homogeneous camera systems. Heterogeneous camera systems (for instance, combine Fisheye and Catadioptric cameras) can also be easily thought of for real applications. However, it has not been quite clear, how accurate stereo vision with these cameras and models can be. In this paper, different accuracy aspects are addressed by analytical inspection, numerical simulation as well as real image data evaluation. This analysis is generic, for any camera projection model, although only polynomial and rational projection models are used for distortion free, Catadioptric and Fisheye lenses. Note that this is different to polynomial and rational radial distortion models which have been addressed extensively in literature. For single camera analysis it turns out that point features towards the image sensor borders are significantly more accurate than in center regions of the sensor. For heterogeneous two camera systems it turns out, that reconstruction accuracy decreases significantly towards image borders as different projective distortions occur.
LABORATORY FLUME EXPERIMENT WITH A CODED STRUCTURED LIGHT SYSTEM
Authors: Akca D. , Seybold H.
Published: August 2012

Abstract. The topography of inland deltas is influenced chiefly by the water-sediment balance in distributary channels and local evaporation and seepage rates. In a previous study, a reduced complexity model has been applied to simulate the process of inland delta formation. Results have been compared with the Okavango Delta, Botswana and with a laboratory experiment. Both in the macro scale and the micro scale cases, high quality digital elevation models (DEM) are essential. This work elaborates the laboratory experiment where an artificial inland delta is generated on laboratory scale and its topography is measured using a Breuckmann 3D scanner. The space-time evolution of the inland delta is monitored in the consecutive DEM layers. Regarding the 1.0m x 1.0m x 0.3m size of the working area, better than 100 micron precision is achieved which gives a relative precision of 1/10 000. The entire 3D modelling workflow is presented in terms of scanning, co-registration, surface generation, editing, and visualization steps. The co-registered high resolution topographic data allows us to analyse the stratigraphy patterns of the experiment and gain quantitative insight into the spatio-temporal evolution of the delta formation process.
DEM ASSESSMENT DERIVED FROM CLOSE RANGE PHOTOGRAMMETRY: A CASE STUDY FROM KADAVUR AREA, KARUR DISTRICT, TAMIL NADU, INDIA
Authors: Anbarasan S. , Sakthivel R.
Published: August 2012

Abstract. Close-Range Photogrammetry is an accurate, cost effective technique of collecting measurements of real world objects and conditions, directly from photographs. Photogrammetry utilizes digital images to obtain accurate measurements and geometric data of the object or area of interest, in order to provide spatial information for Engineering design, spatial surveys or 3D modeling. The benefits of close-range Photogrammetry over other field procedures are purported to be: Increased accuracy; complete as-built information; reduced costs; reduced on-site time; and effective for small and large projects. The same basic principle of traditional Aerial Photogrammetry can be applied to stereoscopic pictures taken from lower altitudes or from the ground. Terrestrial, ground-based, and close-range are all descriptive terms that refer to photos taken with an object-to-camera distance less than 300m (1000 feet). (Matthews, N.A, 2008). Close range Photogrammetry is a technique for obtaining the geometric information (e.g. position, distance, size and shape) of any object in 3D space that was imaged on the two dimensional (2D) photos, (Wolf, P.R, et.al, 2000) DEM Generation requires many processing and computation, such as camera calibration, stereo matching, editing, and interpolation. All the mentioned steps contribute to the quality of DEM. Image on close range Photogrammetry can be captured using three kind of camera: metric camera, semi-metric camera, and non-metric camera (Hanke, K., et.al, 2002). In this paper DEM quality assessed at Kadavur area, Karur district, Tamil Naudu, India using Close Range Photogrammetry technique, Commercial Digital Camera and Leica Photogrammetry Suite.
CLOSE RANGE HYPERSPECTRAL IMAGING INTEGRATED WITH TERRESTRIAL LIDAR SCANNING APPLIED TO ROCK CHARACTERISATION AT CENTIMETRE SCALE
Authors: Kurz T. H. , Buckley S. J. , Howell J. A.
Published: August 2012

Abstract. Compact and lightweight hyperspectral imagers allow the application of close range hyperspectral imaging with a ground based scanning setup for geological fieldwork. Using such a scanning setup, steep cliff sections and quarry walls can be scanned with a more appropriate viewing direction and a higher image resolution than from airborne and spaceborne platforms. Integration of the hyperspectral imagery with terrestrial lidar scanning provides the hyperspectral information in a georeferenced framework and enables measurement at centimetre scale. In this paper, three geological case studies are used to demonstrate the potential of this method for rock characterisation. Two case studies are applied to carbonate quarries where mapping of different limestone and dolomite types was required, as well as measurements of faults and layer thicknesses from inaccessible parts of the quarries. The third case study demonstrates the method using artificial lighting, applied in a subsurface scanning scenario where solar radiation cannot be utilised.
MULTIDIMENSIONAL ROUGHNESS CHARACTERIZATION FOR MICROWAVE REMOTE SENSING APPLICATIONS USING A SIMPLE PHOTOGRAMMETRIC ACQUISITION SYSTEM
Authors: Marzahn P. , Rieke-Zap D. , Wegmuller U. , Ludwig R.
Published: August 2012

Abstract. Soil surface roughness, as investigated in this study, is a critical parameter in microwave remote sensing. As soil surface roughness is treated as a stationary single scale isotropic process in most backscattering models, the overall objective of this study was to better understand the role of soil surface roughness in the context of backscattering. Therefore a simple photogrametric acquisition setup was developed for the characterization of soil surface roughness. In addition several suited SAR images of different sensors (ERS-2 and TerraSAR-X) were acquired to quantify the impact of soil surface roughness on the backscattered signal. Major progress achieved in this work includes the much improved characterization of in-field soil surface roughness. Good progress was also made in the understanding of backscattering from bare surface in the case of directional scattering.
STUDYING GLACIAL MELT PROCESSES USING SUB-CENTIMETER DEM EXTRACTION AND DIGITAL CLOSE-RANGE PHOTOGRAMMETRY
Authors: Sanz-Ablanedo E. , Chandler J. H. , Irvine-Fynn T. D. L.
Published: August 2012

Abstract. Glaciers are sensitive to climatic variation and a particular developing area of investigation is in the field of "cryoconite”, referring to dustlike residues which form on the glacier surface. Cryoconite absorbs the Sun's shortwave energy, accelerates ice melt and because of the localised distribution of dust creates localised melting which is highly spatially variable. There is therefore a need to quantify the detailed topographic surface of ice and measure its variability through time. This paper describes the use of close range photogrammetry to reconstruct the glacier surface at the sub-centimetre or micro scale, an approach which may allow the relationship between cryoconite and ice surface properties to be explored over either space or time. The field campaign was conducted at Midtre Lovénbreen, Svalbard (78.88° North 12.08° East), during the summer of 2010 and executed using simple equipment and procedures. A simple and ageing Nikon 5400 5 MP camera was used to acquire all imagery, proving sufficiently robust for the challenging field environment. The camera was handheld approximately 1.6 m above the ice surface, providing an oblique perspective. Images were acquired at three different camera/object distances, each generating coverage occupying three different areas. All imagery was processed using the commercial photogrammetric package PhotoModeler Scanner, generating threedimensional point clouds consisting of many thousands of XYZ coordinates, each colour-coded. It had been feared that lack of texture in the ice surface combined with differing specular reflections in each image would compromise the DEM generation process. Results were better than expected, although DEM quality proved to be variable depending on ice cleanliness and more significantly, the degree of obliquity of the image pairs. Despite these differences, digital close-range photogrammetry has proven to be a useful technique to reconstruct the glacier's surface to sub-centimeter precision. Moreover, the method is providing glacial scientists with new data to examine the relationship between cryoconite, ice surface roughness and melt processes.
OBJECT-SPACE MULTI-IMAGE MATCHING OF MOBILE-MAPPING-SYSTEM IMAGE SEQUENCES
Authors: Chen Y. C. , Tseng Y. H. , Hsieh C. Y. , Wang P. C. , Tsai P. C.
Published: August 2012

Abstract. This paper proposes an object-space multi-image matching procedure of terrestrial MMS (Mobile Mapping System) image sequences to determine the coordinates of an object point automatically and reliably. This image matching procedure can be applied to find conjugate points of MMS image sequences efficiently. Conventional area-based image matching methods are not reliable to deliver accurate matching results for this application due to image scale variations, viewing angle variations, and object occlusions. In order to deal with these three matching problems, an object space multi-image matching is proposed. A modified NCC (Normalized Cross Correlation) coefficient is proposed to measure the similarity of image patches. A modified multi-window matching procedure will also be introduced to solve the problem of object occlusion. A coarse-to-fine procedure with a combination of object-space multi-image matching and multi-window matching is adopted. The proposed procedure has been implemented for the purpose of matching terrestrial MMS image sequences. The ratio of correct matches of this experiment was about 80 %. By providing an approximate conjugate point in an overlapping image manually, most of the incorrect matches could be fixed properly and the ratio of correct matches was improved up to 98 %.