bluuebunny/crossref_metadata_2025 huggingface dataset:
FEATURE EVALUATION FOR BUILDING FACADE IMAGES – AN EMPIRICAL STUDY
Authors: Yang M. Y. , Förstner W. , Chai D.
Published: August 2012

Abstract. The classification of building facade images is a challenging problem that receives a great deal of attention in the photogrammetry community. Image classification is critically dependent on the features. In this paper, we perform an empirical feature evaluation task for building facade images. Feature sets we choose are basic features, color features, histogram features, Peucker features, texture features, and SIFT features. We present an approach for region-wise labeling using an efficient randomized decision forest classifier and local features. We conduct our experiments with building facade image classification on the eTRIMS dataset, where our focus is the object classes building, car, door, pavement, road, sky, vegetation, and window.
AUTOMATIC CLOUD DETECTION FROM MULTI-TEMPORAL SATELLITE IMAGES: TOWARDS THE USE OF PLÉIADES TIME SERIES
Authors: Champion N.
Published: August 2012

Abstract. Contrary to aerial images, satellite images are often affected by the presence of clouds. Identifying and removing these clouds is one of the primary steps to perform when processing satellite images, as they may alter subsequent procedures such as atmospheric corrections, DSM production or land cover classification. The main goal of this paper is to present the cloud detection approach, developed at the French Mapping agency. Our approach is based on the availability of multi-temporal satellite images (i.e. time series that generally contain between 5 and 10 images) and is based on a region-growing procedure. Seeds (corresponding to clouds) are firstly extracted through a pixel-to-pixel comparison between the images contained in time series (the presence of a cloud is here assumed to be related to a high variation of reflectance between two images). Clouds are then delineated finely using a dedicated region-growing algorithm. The method, originally designed for panchromatic SPOT5-HRS images, is tested in this paper using time series with 9 multi-temporal satellite images. Our preliminary experiments show the good performances of our method. In a near future, the method will be applied to Pléiades images, acquired during the in-flight commissioning phase of the satellite (launched at the end of 2011). In that context, this is a particular goal of this paper to show to which extent and in which way our method can be adapted to this kind of imagery.
FULLY AUTOMATED GENERATION OF ACCURATE DIGITAL SURFACE MODELS WITH SUB-METER RESOLUTION FROM SATELLITE IMAGERY
Authors: Wohlfeil J. , Hirschmüller H. , Piltz B. , Börner A. , Suppa M.
Published: August 2012

Abstract. Modern pixel-wise image matching algorithms like Semi-Global Matching (SGM) are able to compute high resolution digital surface models from airborne and spaceborne stereo imagery. Although image matching itself can be performed automatically, there are prerequisites, like high geometric accuracy, which are essential for ensuring the high quality of resulting surface models. Especially for line cameras, these prerequisites currently require laborious manual interaction using standard tools, which is a growing problem due to continually increasing demand for such surface models. The tedious work includes partly or fully manual selection of tie- and/or ground control points for ensuring the required accuracy of the relative orientation of images for stereo matching. It also includes masking of large water areas that seriously reduce the quality of the results. Furthermore, a good estimate of the depth range is required, since accurate estimates can seriously reduce the processing time for stereo matching. In this paper an approach is presented that allows performing all these steps fully automated. It includes very robust and precise tie point selection, enabling the accurate calculation of the images’ relative orientation via bundle adjustment. It is also shown how water masking and elevation range estimation can be performed automatically on the base of freely available SRTM data. Extensive tests with a large number of different satellite images from QuickBird and WorldView are presented as proof of the robustness and reliability of the proposed method.
COLLABORATIVE WEB GIS PLATFORM FOR SYSTEMATIC EXPLORATION OF LAKE GENEVA
Authors: Akhtman Y. , Martelletti L. , Grandjean O. , Lemmin U.
Published: August 2012

Abstract. We have developed and deployed a Web-based GIS data management framework, which facilitates an effective and highly structured search, retrieval and visualisation of multi-modal scientific data, as well as its subsequent dissemination in multiple and standardised forms beneficial for both the research partners involved in the project and the general public. In the context of the long term objectives of the Élémo project, the developed methodology may be utilised for automated and systematic collection of the multifaceted scientific data and with the goal of assembling a comprehensive database encompassing all aspects of currently planned and future scientific investigations.
VECTORIZATION OF LINEAR FEATURES IN SCANNED TOPOGRAPHIC MAPS USING ADAPTIVE IMAGE SEGMENTATION AND SEQUENTIAL LINE TRACKING
Authors: Yang Y. , An X. , Huang L.
Published: August 2012

Abstract. Vectorization of cartographic features is a difficult task in geographic information acquisition from topographic maps. This paper presents a semi-automatic approach to linear feature vectorization directly in original scanned colour topographic maps without layer separation. In the approach, a sliding window is added on a user-given linear feature, and the current line in the window is segmented adaptively by using colour space conversion, k-means clustering and directional region growing. A thinning operation is then performed in the window and the line is tracked from the centre to the edge. By moving the window continuously along the line, vectorization is carried out by iterative operations of image segmentation, thinning and line tracking. Experimental results show that linear features in colour topographic maps can be vectorized rapidly and accurately, especially in those maps with forest tints and relief shadings.
RESEARCH OF IMAGE MATCHING ALGORITHM BASED ON ROTATION VECTOR FIELD
Authors: Duan Y. S.
Published: August 2012

Abstract. A rotation invariant image matching algorithm is introduced in this paper. The feature descriptor of feature points is calculated in polar coordinate system which achieves rotation invariant. The Wallis filter and image edge extraction are applied to reduce the influence of noise an light difference. After constructing the image feature vectors, the potential correspondences are found firstly and then the Generalized Hough Transform (GHT) is used to purify the matching result . The experiment results of three data sets show that the method is robust to image rotation, time and space efficient and is sufficient to produce matching points which can be used as initial values for further accurate image matching.
DATUM TRANSFORMATION OF SPATIAL DATA AND APPLICATION IN CADASTRE
Authors: Kısa A. , Erkek B. , Ekin L.
Published: August 2012

Abstract. In Turkey, cadastral works have been started with local-based works in 1924 and speeded up after 1950's by using photogrammetry. Different measurement methods, coordinate systems and scales have been used in these works. As a result of primary cadastral activities two main products are generated; cadastral maps and title deeds. After this, cadastral data live on the maps, by cadastral activities carried out by cadastral offices and title deed data live on the registrations by land registration activities carried out by land registration offices. Up to 2005 different references systems such as local (graphic) and ED50 have been used for Cadastral maps production. 2000's Land Registry and Cadastre Information System (TAKBİS) Project has started as a pilot application by Land Registry and Cadastre (TKGM). After completion of pilot project spreading activities started in 2005 and still has been ongoing. On the other hand The government has taken the decision to finish primary cadastral activities within three years. The primary cadastral activities completed at the end of 2008. And also TKGM has completed metadata portal in 2008. At last, cadastral map updating (renovation) started in 2009 by using digital orthophoto with 30 cm GSD. Today people have great expectations in accomplishing digital cadastral services, they need correct, reliable, easy and quick accessible land register and cadastral survey information. Even such request expressed in INPIRE directive by using ISO 191XX data standards. This means we have great hard work for spatial data conversion, datum and data transformation for map and cadastral data harmonization. This paper presents results of investigation of used cadastral maps and used datums of the TKGM and possible transformation methods of datum and some recommendations for future applications.
EXTRACTION OF FOREST STANDS PARAMETERS FROM ASTER DATA IN OPEN FOREST
Authors: Abbasi M. , Riyahi Bakhtyarib H. R.
Published: August 2012

Abstract. Tree crown size (CS) and stem number per hectare (SN) has become increasingly important for forest management and ecosystem monitoring. Tree crown size is also strongly related to other canopy structural parameters, such as diameter at breast height, tree height and biomass. For both issues, remote sensing data are attractive for their large-area and up-to-date mapping capacities. The QuickBird and ASTER imagery used in this study was acquired over Zagros Forests in southern Zagros region, Fars province of Iran on 1 August 2005 and 1 July 2005, respectively. For the forest site investigated in this study, we concentrated on stands of Quercus Persica which is the dominant species in Zagros region. This study was conducted to investigate the capabilities of ASTER-L1B data to estimate some of forest parameters at individual tree and stand level in dry area. The forest stand parameters are crown area, crown density, average crown area. Obtaining the accuracy of classification the ground truth map was prepared by tree crown delineation using the panchromatic band of QuickBird data. Individual tree crowns were automatically delineated by color segmentation of QuickBird imagery. Simple linear regression procedure was used to show the relationships between spectral variables and the individual trees and forest stand parameters. With decreasing the crown density the effects of background will increase. Our results indicated that crown size could be accurately extracted from panchromatic band of QuickBird images especially for open forest stands. This paper demonstrates that using high-resolution satellite imagery in the open forest offers a unique opportunity for deriving single tree attributes and allowing reliable ground truth map to estimate stand structure. ASTER data and its indices showed good capability to estimate crown area in this study.
VERIFICATION OF IMAGE BASED AUGMENTED REALITY FOR URBAN VISUALIZATION
Authors: Fuse T. , Nishikawa S. , Fukunishi Y.
Published: August 2012

Abstract. Recently, visualization of urban scenes with various information attracts attention. For the transmission of urban scenes, virtual reality has been widely used. Since the virtual reality requires comprehensive and detailed three dimensional models, the manual dependent modelling takes a lot of time and effort. On the other hand, it has been tackled that various data is superimposed on the scene which the users see at the time instead of comprehensive modelling, which is well known as augmented reality (AR). Simultaneous localization and mapping (SLAM) has been attempted using simple video cameras for the AR. This method estimates exterior orientation factors of the camera, and three dimensional reconstructions of feature points simultaneously. The method, however, has been applied to only small indoor space. This paper investigates the applicability of the popular method of SALM to wide outdoor space, and improves the stability of the method. Through the application, the tracked feature points successfully are greatly reduced compared with application in indoor environment. According to the experimental result, simple markers or GPS are introduced as auxiliary information. The markers gives the stability of optimization, and GPS gives real scale to AR spaces. Additionally, feature points tracking method is modified by assigning amplitude of displacement and depth. The effect of the markers and GPS are confirmed. On the other hand, some limitations of the method are understood. As a result, more impressive visualization will be accomplished.
A KML-BASED APPROACH FOR DISTRIBUTED COLLABORATIVE INTERPRETATION OF REMOTE SENSING IMAGES IN THE GEO-BROWSER
Authors: Huang L. , Zhu X. , Guo W. , Xiang L. , Chen X. , Mei Y.
Published: August 2012

Abstract. Existing implementations of collaborative image interpretation have many limitations for very large satellite imageries, such as inefficient browsing, slow transmission, etc. This article presents a KML-based approach to support distributed, real-time, synchronous collaborative interpretation for remote sensing images in the geo-browser. As an OGC standard, KML (Keyhole Markup Language) has the advantage of organizing various types of geospatial data (including image, annotation, geometry, etc.) in the geo-browser. Existing KML elements can be used to describe simple interpretation results indicated by vector symbols. To enlarge its application, this article expands KML elements to describe some complex image processing operations, including band combination, grey transformation, geometric correction, etc. Improved KML is employed to describe and share interpretation operations and results among interpreters. Further, this article develops some collaboration related services that are collaboration launch service, perceiving service and communication service. The launch service creates a collaborative interpretation task and provides a unified interface for all participants. The perceiving service supports interpreters to share collaboration awareness. Communication service provides interpreters with written words communication. Finally, the GeoGlobe geo-browser (an extensible and flexible geospatial platform developed in LIESMARS) is selected to perform experiments of collaborative image interpretation. The geo-browser, which manage and visualize massive geospatial information, can provide distributed users with quick browsing and transmission. Meanwhile in the geo-browser, GIS data (for example DEM, DTM, thematic map and etc.) can be integrated to assist in improving accuracy of interpretation. Results show that the proposed method is available to support distributed collaborative interpretation of remote sensing image
DISTRIBUTED INFRASTRUCTURE ENABLING EFFECTIVE INTEGRATION OF EARTH OBSERVATION INFORMATION RESOURCES FOR COLLECTIVE SOLUTION OF ARCHIVING, SEARCHING, PROCESSING AND EO DATA ANALYZING TASKS
Authors: Savorskiy V. P. , Lupyan E. A. , Kaevitser V. I. , Smirnov M. T. , Ermakov D. M. , Balashov I. V. , Bourtsev M. A. , Yu Efremov V. , Proshin A. A. , Tolpin V. A. , Uvarov L. A. , Flitman E. V.
Published: August 2012

Abstract. Numerous applications of Earth observation (EO) data for Earth resource exploration both for land use management purposes and for fundamental research goals require as much as possible independent EO data sets provided for a number of data consumers, i.e. for collective (shared) data usage. In addition data distribution procedures should be accompanied with sophisticated information services enabling correct interpretation and application of provided data. As a result data providers should be able to convert data in a lot of consumer-proper formats and in some cases it should require additional data processing before data shipping. Presented work proposes basic infrastructure for collective (shared) EO data usage that enables above mentioned integration of information resources contained in typical Russian EO centers. Paper reveals architecture design, description of basic infrastructure elements, and examples of real implementations.
AN AUTOMATED END-TO-END MULTI-AGENT QOS BASED ARCHITECTURE FOR SELECTION OF GEOSPATIAL WEB SERVICES
Authors: Shah M. , Verma Y. , Nandakumar R.
Published: August 2012

Abstract. Over the past decade, Service-Oriented Architecture (SOA) and Web services have gained wide popularity and acceptance from researchers and industries all over the world. SOA makes it easy to build business applications with common services, and it provides like: reduced integration expense, better asset reuse, higher business agility, and reduction of business risk. Building of framework for acquiring useful geospatial information for potential users is a crucial problem faced by the GIS domain. Geospatial Web services solve this problem. With the help of web service technology, geospatial web services can provide useful geospatial information to potential users in a better way than traditional geographic information system (GIS). A geospatial Web service is a modular application designed to enable the discovery, access, and chaining of geospatial information and services across the web that are often both computation and data-intensive that involve diverse sources of data and complex processing functions. With the proliferation of web services published over the internet, multiple web services may provide similar functionality, but with different non-functional properties. Thus, Quality of Service (QoS) offers a metric to differentiate the services and their service providers. In a quality-driven selection of web services, it is important to consider non-functional properties of the web service so as to satisfy the constraints or requirements of the end users. The main intent of this paper is to build an automated end-to-end multi-agent based solution to provide the best-fit web service to service requester based on QoS.
AUTOMATING MAPPING PRODUCTION FOR THE ENTERPRISE: FROM CONTRACT TO DELIVERY
Authors: Uebbing R. , Xie C. , Beshah B. , Welter J.
Published: August 2012

Abstract. The ever increasing volume and quality of geospatial data has created new challenges for mapping companies. Due to increased image resolution, fusion of different data sources and more frequent data update requirements, mapping production is forced to streamline the work flow to meet client deadlines. But the data volume alone is not the only barrier for an efficient production work flow. Processing geospatial information traditionally uses domain and vendor specific applications that do not interface with each other, often leading to data duplication and therefore creating sources for error. Also, it creates isolation between different departments within a mapping company resulting in additional communication barriers. North West Geomatics has designed and implemented a data centric enterprise solution for the flight acquisition and production work flow to combat the above challenges. A central data repository containing not only geospatial data in the strictest sense such as images, vector layers and 3D point clouds, but also other information such as product specifications, client requirements, flight acquisition data, production resource usage and much more has been deployed at the company. As there is only one instance of the database shared throughout the whole organization it allows all employees, given they have been granted the appropriate permission, to view the current status of any project with a graphical and table based interface through its life cycle from sales, through flight acquisition, production and product delivery. Not only can users track progress and status of various work flow steps, but the system also allows users and applications to actively schedule or start specific production steps such as data ingestion and triangulation with many other steps (orthorectification, mosaicing, accounting, etc.) in the planning stages. While the complete system is exposed to the users through a web interface and therefore allowing outside customers to also view their data, much of the design and development was focused on work flow automation, scalability and security. Ideally, users will interact with the system to retrieve a specific project status and summaries while the work flow processes are triggered automatically by modeling their dependencies. The enterprise system is built using open source technologies (PostGIS, Hibernate, OpenLayers, GWT and others) and adheres to OGC web services for data delivery (WMS/WFS/WCS) to third party applications.
VALIDATION OF THE ASTER GLOBAL DIGITAL ELEVATION MODEL VERSION 2 OVER THE CONTERMINOUS UNITED STATES
Authors: Gesch D. , Oimoen M. , Zhang Z. , Meyer D. , Danielson J.
Published: August 2012

Abstract. The ASTER Global Digital Elevation Model Version 2 (GDEM v2) was evaluated over the conterminous United States in a manner similar to the validation conducted for the original GDEM Version 1 (v1) in 2009. The absolute vertical accuracy of GDEM v2 was calculated by comparison with more than 18,000 independent reference geodetic ground control points from the National Geodetic Survey. The root mean square error (RMSE) measured for GDEM v2 is 8.68 meters. This compares with the RMSE of 9.34 meters for GDEM v1. Another important descriptor of vertical accuracy is the mean error, or bias, which indicates if a DEM has an overall vertical offset from true ground level. The GDEM v2 mean error of –0.20 meters is a significant improvement over the GDEM v1 mean error of –3.69 meters. The absolute vertical accuracy assessment results, both mean error and RMSE, were segmented by land cover to examine the effects of cover types on measured errors. The GDEM v2 mean errors by land cover class verify that the presence of aboveground features (tree canopies and built structures) cause a positive elevation bias, as would be expected for an imaging system like ASTER. In open ground classes (little or no vegetation with significant aboveground height), GDEM v2 exhibits a negative bias on the order of 1 meter. GDEM v2 was also evaluated by differencing with the Shuttle Radar Topography Mission (SRTM) dataset. In many forested areas, GDEM v2 has elevations that are higher in the canopy than SRTM.
THE IRANIAN NATIONAL GEODATA REVISION STRATEGY AND REALIZATION BASED ON GEODATABASE
Authors: Haeri M. , Fasihi A. , Ayazi S. M.
Published: August 2012

Abstract. In recent years, using of spatial database for storing and managing spatial data has become a hot topic in the field of GIS. Accordingly National Cartographic Center of Iran (NCC) produces – from time to time – some spatial data which is usually included in some databases. One of the NCC major projects was designing National Topographic Database (NTDB). NCC decided to create National Topographic Database of the entire country-based on 1:25000 coverage maps. The standard of NTDB was published in 1994 and its database was created at the same time. In NTDB geometric data was stored in MicroStation design format (DGN) which each feature has a link to its attribute data (stored in Microsoft Access file). Also NTDB file was produced in a sheet-wise mode and then stored in a file-based style. Besides map compilation, revision of existing maps has already been started. Key problems of NCC are revision strategy, NTDB file-based style storage and operator challenges (NCC operators are almost preferred to edit and revise geometry data in CAD environments). A GeoDatabase solution for national Geodata, based on NTDB map files and operators' revision preferences, is introduced and released herein. The proposed solution extends the traditional methods to have a seamless spatial database which it can be revised in CAD and GIS environment, simultaneously. The proposed system is the common data framework to create a central data repository for spatial data storage and management.
USAGE OF STEREO ORTHOIMAGE IN GIS: OLD CONCEPT, MODERN SOLUTION
Authors: Pyka K. , Słota M. , Twardowski M.
Published: August 2012

Abstract. The main goal of this paper is to find answer for two questions: why stereo orthoimage (orthophoto) was forgotten, and furthermore, what conditions have to be fulfilled for this particular technique to be reanimated? Stereo orthophoto concept was first introduced by Collins, during late seventies of last century (Colins, 1968). It has ignited huge interest, and many researchers were looking forward for its development (Blachut 1976, Kraus et al. 1976). However, after around twenty years, interest in stereo-orthophoto has shrunk, and during eighties of XX century it was almost extinct. Despite of fact that digital photogrammetry provides better conditions for it now than ever, it has never got chance for reactivation. There was but few papers about stereo orthoimage, and they are proposing continuous stereo ortho-mosaic generation while preserving its metric value (Li et al 2002, Wang 2004). Reasons of downfall of this interest were examined, and it has been concluded that the main cause was usage of this technique in conjunction with analog photogrammetry. The radiometric value of orthophotomaps and stereo components developed on photosensitive paper were very low during that time. Equipment for observation and measurement were simply very big and therefore impractical. Authors have concluded, that nowadays sum of gains outweighs its flaws and it is reason enough to go back to it. But in a time of digital vector 3D models there is a need for proper strategy for popularization stereo orthophoto. Main point of this strategy would be encapsulating stereo orthoimage method into GIS tools, optimally open source. GIS have large numbers of consumers whom regard for orthophotomap (or orthoimage) is very high. If they were to be proposed with possibility of using stereo orthoimage inside a GIS tool, as a complementary to the orthophotomap, probably they would recon how much stereoscopy helps with interpretation of an image. Authors have planned to develop software for utilization of stereo orthoimage available from the Quantum GIS interface, and test version is to be based on anaglyph stereoscopy. Value of creating continuous stereo-mosaic composed from many 3D models was assessed. Consensus was, however, that this solution surprises us with frequent perspective changes which leads to discomfort. As an outcome it was decided to focus on single stereo orthoimage pairs. When area constrains are specified for single model, one can load them as requested by an user. In case of increased lateral and longitudinal coverage, which is more common in modern aerial photogrammetric flights, every localization will be accessible for visualization using several models, and there will be less concealed areas. Few algorithms for generation of parallax are tested. After completion of sets from a dozen or so example models of interesting areas are gathered, there will be release. Authors are confident that stereo orthoimage may prove more useful for GIS users than true orthophotomap.
A BOTTOM-UP GEOSPTIAL DATA UPDATE MECHANISM FOR SPATIAL DATA INFRASTRUCTURE UPDATING
Authors: Tian W. , Zhu X. , Liu Y.
Published: August 2012

Abstract. Currently, the top-down spatial data update mechanism has made a big progress and it is wildly applied in many SDI (spatial data infrastructure). However, this mechanism still has some issues. For example, the update schedule is limited by the professional department’s project, usually which is too long for the end-user; the data form collection to public cost too much time and energy for professional department; the details of geospatial information does not provide sufficient attribute, etc. Thus, how to deal with the problems has become the effective shortcut. Emerging Internet technology, 3S technique and geographic information knowledge which is popular in the public promote the booming development of geoscience in volunteered geospatial information. Volunteered geospatial information is the current "hotspot", which attracts many researchers to study its data quality and credibility, accuracy, sustainability, social benefit, application and so on. In addition to this, a few scholars also pay attention to the value of VGI to support the SDI updating. And on that basis, this paper presents a bottom-up update mechanism form VGI to SDI, which includes the processes of match homonymous elements between VGI and SDI vector data , change data detection, SDI spatial database update and new data product publication to end-users. Then, the proposed updating cycle is deeply discussed about the feasibility of which can detect the changed elements in time and shorten the update period, provide more accurate geometry and attribute data for spatial data infrastructure and support update propagation.
openemotionmap.org – Emotional response to space as an additional concept in cartography
Authors: Gartner G.
Published: August 2012

Abstract. In this submission the concept is analysed, that the emotional relation and the degree of emotional response is structuring space and can therefore be relevant for human wayfinding. Possible measures for linking explicit links between person’s memory/experience/emotional response with the physical environment are investigated and possible applications for navigation systems are discussed.
EXPLORING THE MOON WITH THE LUNAR RECONNAISSANCE ORBITER CAMERA
Authors: Robinson M. S. , Speyerer E. J. , Boyd A. , Waller D. , Wagner R. V. , Burns K. N.
Published: August 2012

Abstract. The Lunar Reconnaissance Orbiter Camera (LROC) consists of three imaging systems: a Wide Angle Camera (WAC) and two Narrow Angle Cameras (NACs). Since entering lunar orbit in June of 2009, LROC has collected over 700,000 images. A subset of WAC images were reduced into a global morphologic basemap, a near-global digital elevation model, and multitemporal movie sequences that characterize illumination conditions of the polar regions. In addition, NAC observations were reduced to meter scale maps and digital elevation models of select regions of interest. These Reduced Data Record (RDR) products were publicly released through NASA’s Planetary Data System to aid scientists and engineers in planning future lunar missions and addressing key science questions.
IN-FLIGHT GEOMETRIC CALIBRATION OF THE LUNAR RECONNAISSANCE ORBITER CAMERA
Authors: Speyerer E. J. , Wagner R. V. , Robinson M. S. , Humm D. C. , Becker K. , Anderson J. , Thomas P.
Published: August 2012

Abstract. The Lunar Reconnaissance Orbiter Camera (LROC) consists of two imaging systems that provide synoptic and high resolution imaging of the lunar surface. The Wide Angle Camera (WAC) is a seven color push frame imager with a 90° field of view in monochrome mode and 60° field of view in color mode. From the nominal 50 km polar orbit, the WAC acquires images with a nadir pixel scale of 75 m for each visible band and 384 m for the two ultraviolet bands. The Narrow Angle Camera (NAC) consists of two identical cameras capable of acquiring images with a pixel scale of 0.5 to 1.0 m from a 50 km orbit. Each camera was geometrically calibrated prior to launch at Malin Space Science Systems in San Diego, California. Using thousands of images acquired since launch in June of 2009, improvements to the relative and absolute pointing of the twin NACs were made allowing images on the surface to be projected with an accuracy of 20 meters. Further registration of WAC and NAC images allowed the derivation of a new distortion model and pointing updates for the WAC, thus enabling sub-pixel accuracy in projected WAC images.
ARCGIS DATA MODELS FOR MANAGING AND PROCESING IMAGERY
Authors: Xu H. , Becker P.
Published: August 2012

Abstract. As remote sensing technology advances, imagery becomes one of the most important data sources for GIS applications –as it can quickly provide the most current and most detailed information with high resolution image data. Traditional image processing workflow becomes inefficient in GIS applications especially in the case of disaster analysis. This paper introduces two ArcGIS data models that are designed for on-demand image processing in managing imagery: raster product and mosaic dataset. A raster product allows you to access single scene remote sensing image products dynamically such as a pan-sharpened and orthorectified GeoEye image or multi-spectral Landsat scene with a single drag and drop to the map display. Mosaic datasets allow you to catalog a large collection of images from many sensor platforms, process them on-the-fly and dynamically mosaic the images together. The key concept – the raster function that is used to implement on-the-fly image processing capabilities – will also be discussed.
IMPLEMENTATION OF ZOOM-DEPENDENT CAMERA CALIBRATION IN CLOSE-RANGE PHOTOGRAMMETRY
Authors: Fraser C. S. , Cronk S. , Stamatopoulos C.
Published: August 2012

Abstract. The application of consumer-grade cameras for photogrammetric measurement has traditionally been subject to the requirement that imagery is recorded at fixed zoom and focus settings. The camera is then metrically calibrated, usually via self-calibration, for the lens setting employed. This requirement arises since camera parameters, and especially principal distance and lens distortion coefficients, vary significantly with zoom/focus setting. A recently developed process, titled zoom-dependent (Z-D) calibration, removes the necessity for the zoom setting to be fixed during the image capture process. Implementation of Z-D calibration requires that the camera be pre-calibrated at four or more focal settings within the zoom range, nominally at shortest and longest focal lengths, and at two mid-zoom settings. This requirement, coupled with issues of data management in carrying different focal settings for potentially every image within a bundle adjustment, has largely accounted for the reason that Z-D calibration has not previously been implemented within COTS software for close-range photogrammetry. The objective of this paper is to describe the practical implementation of Z-D calibration within software, along with its associated workflow, and to discuss issues that impact upon the accuracy, reliability and appropriateness of the technique. Experimental testing is used to highlight the merits and shortcomings of ZD calibration.
CYLINDER-BASED SELF-CALIBRATION OF A PANORAMIC TERRESTRIAL LASER SCANNER
Authors: Chan T. On , Lichti D. D.
Published: August 2012

Abstract. Terrestrial Laser Scanners (TLSs) have become state-of-the-art metrological sensors for many surveying purposes in recent years. Due to the demand for high precision surveying with TLSs, efficient, rigorous and in-situ calibration methodologies are always desired. Recent research on in-situ calibration with planar features has demonstrated improved cost-effectiveness and promising results (Glennie and Lichti, 2010; Chow et al., 2011; Chow et al., 2012). However, if there is a need for calibrating the scanners when sufficient plane surfaces with several orientations are not available, as commonly occurs indoors, other common geometric features, namely cylindrical structures, can be used as alternative geometric constraints for in-situ self-calibration. Cylindrical features can be found in indoor environments such as water pipes attached to the walls or suspended from ceilings, concrete pillars, metal poles and many others. In this paper, three 3D models of cylinders, with vertical and horizontal orientations containing one scaling, two rotational and two translational parameters are discussed. The cylinder models are parameterized with the sexternal orientation parameters and the additional parameters as the least-squares functional models for the self-calibration. The selfcalibration is examined with the real data obtained from the Lecia HDS6100 panoramic TLS. The results of vertical, horizontal and mixed cylinder-based calibration with data captured by different scanner position are analysed in detail in terms of the parameters correlations. The results show realistic estimation of calibration parameters for several cases. The results also suggest that using both vertical and horizontal cylinders for the calibration can effectively decorrelate the parameters especially for the case of lack of cylinder point cloud overlap. The concepts developed in this paper might also be extended to the hybrid type TLSs, as well as to the self-calibration of airborne laser scanning (ALS) using cylindrical features such as oil pipes or other large scale cylindrical infrastructure.
AUTOMATIC PROCESSING OF MOBILE LASER SCANNER POINT CLOUDS FOR BUILDING FAÇADE DETECTION
Authors: Arachchige N. H. , Perera S. N. , Maas H.-G.
Published: August 2012

Abstract. Currently, data captured by Mobile Laser Scanners (MLS) is becoming a leading source for the modelling of building façade geometry. Automatic processing of MLS point clouds for feature extraction on building facades is a demanding work. Point cloud segmentation and recognition are the most important steps in this context. In this paper, a new approach for automatic and fast processing of MLS data for the detection of building patches while restricting to segment other features is introduced. After filtering of the point clouds, the building façade extraction takes place. An initial building point cluster detection and roughness based point separation within the cluster itself are the preliminary stages of this process. Thereafter points are segmented into planar patches based on the Random Sample Consensus (RANSAC) technique, as most facades are dominated by planar faces. An intelligent seed point selection method is introduced, and growing rules are applied in order to extract the most significant planar features which represent the building facades. Each segmented plane is afterwards processed to recognize the façade features. A rule based partitioning tree, constructed from the 2D geometric knowledge of building features is used for facade feature recognition. The approach has been tested with several urban data sets, and results demonstrate that the method can be applied in an efficient modelling process.
CURB-BASED STREET FLOOR EXTRACTION FROM MOBILE TERRESTRIAL LIDAR POINT CLOUD
Authors: Ibrahim S. , Lichti D.
Published: August 2012

Abstract. Mobile terrestrial laser scanners (MTLS) produce huge 3D point clouds describing the terrestrial surface, from which objects like different street furniture can be generated. Extraction and modelling of the street curb and the street floor from MTLS point clouds is important for many applications such as right-of-way asset inventory, road maintenance and city planning. The proposed pipeline for the curb and street floor extraction consists of a sequence of five steps: organizing the 3D point cloud and nearest neighbour search; 3D density-based segmentation to segment the ground; morphological analysis to refine out the ground segment; derivative of Gaussian filtering to detect the curb; solving the travelling salesman problem to form a closed polygon of the curb and point-inpolygon test to extract the street floor. Two mobile laser scanning datasets of different scenes are tested with the proposed pipeline. The results of the extracted curb and street floor are evaluated based on a truth data. The obtained detection rates for the extracted street floor for the datasets are 95% and 96.53%. This study presents a novel approach to the detection and extraction of the road curb and the street floor from unorganized 3D point clouds captured by MTLS. It utilizes only the 3D coordinates of the point cloud.
AN AUTOMATIC PROCEDURE FOR COMBINING DIGITAL IMAGES AND LASER SCANNER DATA
Authors: Moussa W. , Abdel-Wahab M. , Fritsch D.
Published: August 2012

Abstract. Besides improving both the geometry and the visual quality of the model, the integration of close-range photogrammetry and terrestrial laser scanning techniques directs at filling gaps in laser scanner point clouds to avoid modeling errors, reconstructing more details in higher resolution and recovering simple structures with less geometric details. Thus, within this paper a flexible approach for the automatic combination of digital images and laser scanner data is presented. Our approach comprises two methods for data fusion. The first method starts by a marker-free registration of digital images based on a point-based environment model (PEM) of a scene which stores the 3D laser scanner point clouds associated with intensity and RGB values. The PEM allows the extraction of accurate control information for the direct computation of absolute camera orientations with redundant information by means of accurate space resection methods. In order to use the computed relations between the digital images and the laser scanner data, an extended Helmert (seven-parameter) transformation is introduced and its parameters are estimated. Precedent to that, in the second method, the local relative orientation parameters of the camera images are calculated by means of an optimized Structure and Motion (SaM) reconstruction method. Then, using the determined transformation parameters results in having absolute oriented images in relation to the laser scanner data. With the resulting absolute orientations we have employed robust dense image reconstruction algorithms to create oriented dense image point clouds, which are automatically combined with the laser scanner data to form a complete detailed representation of a scene. Examples of different data sets are shown and experimental results demonstrate the effectiveness of the presented procedures.
TOWARDS TRANSPARENT QUALITY MEASURES IN SURFACE BASED REGISTRATION PROCESSES: EFFECTS OF DEFORMATION ONTO COMMERCIAL AND SCIENTIFIC IMPLEMENTATIONS
Authors: Wujanz D.
Published: August 2012

Abstract. Terrestrial Laser Scanners have been widely accepted as a surveying instrument in research as well as in commercial applications. While aspects of scanner accuracy and other influential impacts onto the measured values have been extensively analysed, the impact of registration methods and especially the assessment of transformation parameters remained outside the scientific focus. To this day the outcome of a surface based registration, such as ICP or 4PCS, is usually described by a single number representing several thousand points that have been used to derive the transformation parameters. This description neglects established perceptions in geodesy where for instance distribution, size of all derived residuals and its location are considered. This contribution proposes a more objective view on the outcome of registration processes and compares new approaches to results derived with commercial solutions. The impact of deformation is also analysed in order to determine if available solutions are able to cope with this problem.
USING VISION METROLOGY SYSTEM FOR QUALITY CONTROL IN AUTOMOTIVE INDUSTRIES
Authors: Mostofi N. , Samadzadegan F. , Roohy Sh. , Nozari M.
Published: August 2012

Abstract. The need of more accurate measurements in different stages of industrial applications, such as designing, producing, installation, and etc., is the main reason of encouraging the industry deputy in using of industrial Photogrammetry (Vision Metrology System). With respect to the main advantages of Photogrammetric methods, such as greater economy, high level of automation, capability of noncontact measurement, more flexibility and high accuracy, a good competition occurred between this method and other industrial traditional methods. With respect to the industries that make objects using a main reference model without having any mathematical model of it, main problem of producers is the evaluation of the production line. This problem will be so complicated when both reference and product object just as a physical object is available and comparison of them will be possible with direct measurement. In such case, producers make fixtures fitting reference with limited accuracy. In practical reports sometimes available precision is not better than millimetres. We used a non-metric high resolution digital camera for this investigation and the case study that studied in this paper is a chassis of automobile. In this research, a stable photogrammetric network designed for measuring the industrial object (Both Reference and Product) and then by using the Bundle Adjustment and Self-Calibration methods, differences between the Reference and Product object achieved. These differences will be useful for the producer to improve the production work flow and bringing more accurate products. Results of this research, demonstrate the high potential of proposed method in industrial fields. Presented results prove high efficiency and reliability of this method using RMSE criteria. Achieved RMSE for this case study is smaller than 200 microns that shows the fact of high capability of implemented approach.
ASSISTED CONTROL POINT MEASUREMENT FOR CLOSE RANGE PHOTOGRAMMETRY.
Authors: Mata E. , Hernandez M. A. , Cardenal J. , Perez J. L.
Published: August 2012

Abstract. This paper describes the automation and optimization in control points measurement and elaboration of sketches in Close Range Photogrammetry. The system can be controlled by an operator alone and it integrates a robotized and reflectorless total station, two digital cameras, a laptop computer and the control software. The measured data with the station are registered and the control point will get associated to their marks in the images. So, it is possible to eliminate the handmade sketches since the marking of control points in the image is instantaneously made. The sketch includes object images with enlargements so the point is clearly identified and marked with the support of a virtual reticle. Also the sketch includes object coordinates, image coordinates, identification code (ID) and some additional information about the point. The use of the system by only one operator allows the reduction of costs, organization and time in control point surveying. Different tests have been made in order to check the system. TDC: this test has been made in close range conditions with targets and artificial illumination. EDIF: in this case the test includes long range conditions and control points targeted at natural points in building façade. The tests have allowed several analyses to study the feasibility and the improvement of the system. So we have made in situ tests by comparing direct observations with and without the camera telescope, with targets and natural points, close and long distances and different conditions of illumination. Moreover in one of these tests we include the observation and sketch realization with a manual method. With respect to the use of the aiming eyepiece camera, the tests (TDC) realized in laboratory (close distance -4 m- and good light conditions) show very small spatial differences (below the nominal precision of the total station) comparing the direct aim through the telescope without camera. Other test (EDIF) made over longer distance (130 m) and natural targets show differences of few centimeters. Hence, the appending of the eyepiece camera does not involve an excessive aiming error. On the other hand, the improvement of the system is relevant in the observation, measurement and registration of control points. Hence, the decrease of tasks involved and the use the system by an operator reduce the total time employed in two thirds. Although the aim is not completely accurate, the approximation is enough so the final aim is quickly achieved and the lost of time is negligible. After these tests, this system has shown to be an affordable and fully operational method that optimize and reduce the cost and time of control point measurements.