Geospatial Web Services Research Articles

Ключові складники універсальної методики аналізу міри антропізації ландшафтних агрегацій в межах території України

Four European and national conceptions for identification of landscapes’ anthropization extent were considered and differentiated. The mentioned conceptions are conceptions of archiretrospective (naturalness), sozological-idealized (wilderness), actual-potential (hemeroby) and geoecological-naturemanagement analysis. Landscape anthropization is a process of their transformation through anthropogenic impact with specific intensity and consequences of this process, as a result it can be identified existence geosystems with different anthropization level. Alongside, conceptual bases and procedure of anthropization extent’ analysis for Ukrainian landscapes were covered. The procedure is interoperable for all-European and Ukrainian approaches and consists of four components: common-matter, parametric, logic-mathematical and verification implementation component. It embodies scheme and scales of landscapes’ anthropization extent depending on anthropogenic impact’ extent of land use and land cover systems. This impact is specified by corresponding degrees of hemeroby, impact intensity, geoecological favourableness and naturalness of indicated systems. The scale of geoecological situation in land use was also developed. Means were defined for verification and implementation of the procedure concerning landscape aggregations within the territory of Ukraine. Up-to-date and potential geoinformation basis, including GIS technology, satellite imageries, and geospatial web services, was investigated for examination of land covers and land use systems, for cartographic visualization and quantitative data obtaining of the landscape anthropization extent. The possibility of the practical verification and application of this procedure for landscape aggregations within the territory of Ukraine was revealed to determine the state and resilience of geosystems to anthropogenic pressure. Newly represented interoperable procedure will give opportunity to make more rational management decisions in evaluating potential and existing geoecological risks, in defining impact limits, permissible pressure on landscape or natural complexes. This is necessary to ensure sustainable environmental management, territory rational organization, optimal landscape planning and monitoring of anthropogenic activity.

Linked Data and SDI: The case on Web geoprocessing workflows

Linked Data transforms traditional ways of structuring, publishing, discovering, accessing, and integrating data. The advantages of Linked Data, including the common data model, standardized data access mechanism, and link-based data discovery, allow effective sharing and discovery of geospatial resources in Spatial Data Infrastructures (SDI). Web geoprocessing workflows have been widely used in SDI to support distributed geoprocessing. Geospatial data and services are discovered from SDI and chained as geoprocessing workflows. Workflow results can be published as new resources in SDI. The whole process could be improved by the Linked Data approach, so that sensors, observations, data, services, workflows, and provenance can be linked and published into the Web of Data. This paper explores the integration of Linked Data and Web geoprocessing workflows by discovering geospatial resources in the Web of Data to build geoprocessing workflows. It adopts the Linked Data approach to publish geospatial data including in-situ observations and satellite images, as well as geospatial Web services. The workflow results, including data products and processing steps, are also exposed as Linked Data in turn for tracing provenance. The results not only support semantic discovery and integration of heterogeneous geospatial resources, but also provide transparency in data sharing and processing. The approach is implemented as extensions to an existing geoprocessing workflow tool, GeoJModelBuilder, to illustrate its applicability.

Особенности построения геопространственных веб-приложений и сервисов для систем мониторинга состояния окружающей природной среды

Особенности построения геопространственных веб-приложений и сервисов для систем мониторинга состояния окружающей природной среды

A Scalable Geospatial Web Service for Near Real-Time, High-Resolution Land Cover Mapping

A land cover classification service is introduced toward addressing current challenges on the handling and online processing of big remote sensing data. The geospatial web service has been designed, developed, and evaluated toward the efficient and automated classification of satellite imagery and the production of high-resolution land cover maps. The core of our platform consists of the Rasdaman array database management system for raster data storage and the open geospatial consortium web coverage processing service for data querying. Currently, the system is fully covering Greece with Landsat 8 multispectral imagery, from the beginning of its operational orbit. Datasets are stored and preprocessed automatically. A two-stage automated classification procedure was developed which is based on a statistical learning model and a multiclass support vector machine classifier, integrating advanced remote sensing and computer vision tools like Orfeo Toolbox and OpenCV. The framework has been trained to classify pansharpened images at 15-m ground resolution toward the initial detection of 31 spectral classes. The final product of our system is delivering, after a postclassification and merging procedure, multitemporal land cover maps with 10 land cover classes. The performed intensive quantitative evaluation has indicated an overall classification accuracy above 80%. The system in its current alpha release, once receiving a request from the client, can process and deliver land cover maps, for a 500- $\text{km}^2$ region, in about 20 s, allowing near real-time applications.

Applicability of Responsive Web of Geo-Spatial Web Services

As a recent dominant web trend, mobile first strategy has been emphasized, and interests with respect to responsive web that provides effective methodology to various mobile devices and their display resolution are also increasing. However, it is an early adoption stage in web mapping for geo-spatial applications. This study is to present some practical examples of layouts using responsive web technologies linked to geo-spatial open platform. Suggestive consideration points for further application of responsive web to geo-spatial services are presented. On test implementing, HTML5, JavaScript, and CSS3 were used, and web mapping processing using OpenLayers was performed. It is expected that responsive web applications for contents derived from geo-spatial information or location data increase.

공간정보 기반의 협업지원플랫폼 분석 및 구축

The fact that the limits of information recency, diversity, and usability are mainly caused by the supply oriented geospatial data and service development is commonly recognized. It is recently tried to overcome the limits by facilitating user experience and VGI(Volunteered Geographic Information) in several geospatial web services. This study suggests conceptual architecture and service scenario for geospatial collaborative platform prototype through review and examination of previous researches. The prototype, composed of 4 unit modules: 3D POI Creation Module, 3D POI Application Module, 3D POI/Event Management Module, 3D POI/Event Monitoring Module, provides the capability of collaboratively dealing with geospatial work. The suggested service scenario is demonstrated by developing prototype for the service modules.

An integrated heterogeneous web service retrieval via combination of instance- and metadata-based schema matching method

Schema matching is a critical step in the integration of heterogeneous web service, which contains various types of web services and multi-version services of the same type. Mapping loss or mismatch usually occurs due to schema differences in structure and content and the variety in concept definition and organization. Current instance schema matching methods are not mature enough for heterogeneous web service because they cannot deal with the instance data in web service domain and capture all the semantics, especially metadata semantics. The metadata-based and the instance-based matching methods, in the case of being employed individually, are not efficient to determine the concept relationships, which are crucial for finding high-quality matches between schema attributes. In this paper, we propose an improved schema matching method, based on the combination of instance and metadata (CIM) matcher. The main method of our approach is to utilize schema structure, element labels, and the corresponding instance data information. The matching process is divided into two phases. In the first phase, the metadata-based matchers are used to compute the element label similarity of multi-version open geospatial consortium web service schema, and the generated matching results are raw mappings, which will be reused in the next instance matching phase. In the second phase, the designed instance matching algorithms are employed to the instance data of the raw mappings and fine mappings are generated. Finally, the raw mappings and the fine mappings are combined, and the final mappings are obtained. Our experiments are executed on different versions of web coverage service and web feature service instance data deployed in Geoserver. The results indicate that, the CIM method can obtain more accurate matching results and is flexible enough to handle the web service instance data.

DEVELOPING A MAP USE MODEL FOR WEB MAPPING AND GIS

Abstract. Web mapping and GIS technology and applications are developing rapidly in response to growing user and application demands. Technologies over the past decade, including digital globes, positioning-enabled mobile devices and cloud-based geoweb services, have been instrumental in fostering this growth. However, not only technology, but the dissemination and access to geoweb information and services by users and applications have been and are continuing to be important drivers of growth and expansion. The access and use of geospatial information and services is widespread and worldwide, and its use is driving the need to further develop and expand geospatial web information and services. This paper considers a model for web mapping use that is based on the original map use cube by MacEachren & Kraak (1997). The model incorporates technology, usability and knowledge that must be considered for the development and future of geospatial web mapping and services. Such a model assists in the design and development of intelligent web mapping and GIS, and informs the research directions being taken in this fast evolving discipline.

Performance improvement techniques for geospatial web services in a cyberinfrastructure environment – A case study with a disaster management portal

High population growth, urbanization, and global climate change drive up the frequency of disasters, affecting the safety of people’s lives and property worldwide. Because of the inherent big-data nature of this disaster-related information, the processes of data exchange and transfer among physically distributed locations are increasingly challenging. This paper presents our proposed efficient network transmission model for interoperating heterogeneous geospatial data in a cyberinfrastructure environment. This transmission model supports multiple data encoding methods, such as GML (Geography Markup Language) and GeoJSON, as well as data compression/decompression techniques, including LZMA and DEFLATE. Our goal is to tackle fundamental performance issues that impact efficient retrieval of remote data. Systematic experiments were conducted to demonstrate the superiority of the proposed transmission model over the traditional OGC Web Feature Service (WFS) transmission model. The experiments also identified the optimized configuration for data encoding and compression techniques in different network environments. To represent a real-world user request scenario, the Amazon EC2 cloud platform was utilized to deploy multiple client nodes for the experiments. A web portal was developed to integrate the real-time geospatial web services reporting with real-time earthquake related information for spatial policy analysis and collaborative decision-making.

USING THE GEOSPATIAL WEB TO DELIVER AND TEACH GISCIENCE EDUCATION PROGRAMS

Abstract. Geographic information science (GIScience) education has undergone enormous changes over the past years. One major factor influencing this change is the role of the geospatial web in GIScience. In addition to the use of the web for enabling and enhancing GIScience education, it is also used as the infrastructure for communicating and collaborating among geospatial data and users. The web becomes both the means and the content for a geospatial education program. However, the web does not replace the traditional face-to-face environment, but rather is a means to enhance it, expand it and enable an authentic and real world learning environment. This paper outlines the use of the web in both the delivery and content of the GIScience program at Curtin University. The teaching of the geospatial web, web and cloud based mapping, and geospatial web services are key components of the program, and the use of the web and online learning are important to deliver this program. Some examples of authentic and real world learning environments are provided including joint learning activities with partner universities.

Adding Geospatial Data Provenance into SDI—A Service-Oriented Approach

Geospatial data provenance records the derivation history of a geospatial data product. It is important in evaluating the quality of data products. In a Geospatial Web Service environment where data are often disseminated and processed widely and frequently in an unpredictable way, it is even more important in identifying original data sources, tracing workflows, updating or reproducing scientific results, and evaluating reliability and quality of geospatial data products. Geospatial data provenance has become a fundamental issue in establishing the spatial data infrastructure (SDI). This paper investigates how to support provenance awareness in SDI. It addresses key issues including provenance modeling, capturing, and sharing in a SDI enabled by interoperable geospatial services. A reference architecture for provenance tracking is proposed, which can accommodate geospatial feature provenance at different levels of granularity. Open standards from ISO, World Wide Web Consortium (W3C), and OGC are leveraged to facilitate the interoperability. At the feature type level, this paper proposes extensions of W3C PROV-XML for ISO 19115 lineage and “Parent Level” provenance registration in the geospatial catalog service. At the feature instance level, light-weight lineage information entities for feature provenance are proposed and managed by Web Feature Services. Experiments demonstrate the applicability of the approach for creating provenance awareness in an interoperable geospatial service-oriented environment.

Enhancing Agricultural Geospatial Data Dissemination and Applications Using Geospatial Web Services

There are many important publicly available agricultural geospatial data products for the agriculture-related research, applications, and educational outreach programs. The traditional data distribution method cannot fully meet users' on-demand geospatial data needs. This paper presents interoperable, standard-compliant Web services developed for geospatial data access, query, retrieval, statistics, mapping, and comparison. Those standard geospatial Web services can be integrated in scientific workflows to accomplish specific tasks or consumed over the Web to create value-added new geospatial application by users. In addition, this paper demonstrates, via real world use cases, applications of those services and potential impacts on facilitating geospatial Cropland Data Layer (CDL) retrieval, analysis, visualization, dissemination and integration in agricultural industry, government, research, and educational communities. This paper also shows that the geospatial Web service approach helps improve the reusability, interoperability, dissemination, and utilization of agricultural geospatial data. It allows for integrating multiple online applications and different geospatial data sources, and enables automated retrieving and delivery of agricultural geospatial information for decision-making support.

Collaborative planning of inner-city-railway-tracks: A generic description of the geographic context and its dynamic integration in a collaborative multi-scale geometry modelling environment

Planning sub terrestrial inner-city-railway-tracks is an interdisciplinary and highly complex task, which involves plenty of different stakeholders. Currently, the different planners work more or less separated in an asynchronous manner. To facilitate a collaborative planning process between these different stakeholders we developed a collaboration platform. Clearly, the integration of geographical information and geoprocessing results into the planning process and the different modelling tools will improve this process in a significant way. In this paper, we show how to describe the needed geographical information by so-called Geospatial Web Service Context Documents in a suitable way and how to integrate these pieces of information into the different planning tools via the collaboration platform in a unified, dynamic, and generic way.

A web-based system for supporting global land cover data production

Global land cover (GLC) data production and verification process is very complicated, time consuming and labor intensive, requiring huge amount of imagery data and ancillary data and involving many people, often from different geographic locations. The efficient integration of various kinds of ancillary data and effective collaborative classification in large area land cover mapping requires advanced supporting tools. This paper presents the design and development of a web-based system for supporting 30-m resolution GLC data production by combining geo-spatial web-service and Computer Support Collaborative Work (CSCW) technology. Based on the analysis of the functional and non-functional requirements from GLC mapping, a three tiers system model is proposed with four major parts, i.e., multisource data resources, data and function services, interactive mapping and production management. The prototyping and implementation of the system have been realised by a combination of Open Source Software (OSS) and commercially available off-the-shelf system.This web-based system not only facilitates the integration of heterogeneous data and services required by GLC data production, but also provides online access, visualization and analysis of the images, ancillary data and interim 30m global land-cover maps. The system further supports online collaborative quality check and verification workflows. It has been successfully applied to China’s 30-m resolution GLC mapping project, and has improved significantly the efficiency of GLC data production and verification. The concepts developed through this study should also benefit other GLC or regional land-cover data production efforts.

Identifying geospatial inconsistency of web services metadata using spatial ranking

Geospatial metadata is one of the key elements of the geographic resource catalogues on the Web. Catalogues such as GeoNetwork use the direct and indirect spatial references from metadata to process spatial queries. The visibility of resources in a collection often depends on the consistency of the descriptions that help to find resources. Spatially inconsistent metadata records can hide resources and make them irretrievable. This paper presents a semi-automatic approach based on the combination of spatial ranking, reverse geocoding, geographic knowledge organization systems, and information retrieval techniques able to detect geospatial inconsistencies in metadata collections. Experimental results with a dataset of Geospatial Web Service metadata records show that this approach provides a significant advantage in terms of inconsistency detection, and rich insight into the metadata. People responsible of geospatial catalogues, such as librarians and Spatial Data Infrastructure managers, could take advantage of the approach presented in this work to assess the visibility of their assets.

A Sub-Chain Ranking and Recommendation Mechanism for Facilitating Geospatial Web Service Composition

With a huge volume of geospatial information being collected and a huge number of domain-specific functions being developed for processing these geospatial information, an increasing number of Open Geospatial Consortium Web services (OWSs) are built and being available on the Web for the accessibility and processing of these information. Given the specific requirement specified by a certain user, normally, a composition (or chain) of OWSs, rather than a single OWS, can fulfill this requirement. Consequently, retrieving and recommending sub-chains of possible service invocations is an important research challenge. Leveraging the semantic similarity between the name and text description of parameters, a degree that represents the invocation possibility between operations in OWSs is calculated. Thereafter, a service network model is constructed for capturing possible invocations between operations. Given a user's requirement which is represented in terms of a pair of initial and ending operations, possible sub-chains of operations are retrieved, ranked and recommended. Based on which the user can select the most appropriate sub-chain with respect to her specific requirement. The result of evaluation leveraging a real OWSs set indicates that our technique is applicable in real applications from both the functional and performance perspectives.

지리공간 웹 서비스 기반의 기준점 자동추출 기법 연구

지리공간 웹 서비스 기반의 기준점 자동추출 기법 연구

사용자 참여형 공간정보 웹서비스의 가치사슬분석

일반적으로 공급중심의 공간정보 데이터 구축 및 서비스 개발은 정보의 최신성, 다양성, 활용성의 한계를 수반한다. 최근 이러한 한계점을 극복하기 위하여 공간정보 웹서비스에 사용자 경험과 참여기반의 공간정보(VGI: Volunteered Geographic Information)를 활용하려는 노력들이 이루어지고 있다. 본 연구는 선행연구를 검토하여 VGI를 지원하는 공간정보 웹서비스의 10C 프레임워크를 제안하였다. 또한 10C 프레임워크를 기반으로, 사용자 참여를 통하여 VGI를 생산하는 23개 공간정보 웹서비스의 가치사슬체계를 분석하였다. 가치사슬 분석결과를 바탕으로 VGI의 생산, 수집, 전달, 이용 측면에서 공공 공간정보의 가치증진을 위한 시사점을 도출하였다. The fact that the limits of information recency, diversity, and usability are mainly caused by the supply oriented geospatial data and service development is commonly recognized. It is recently tried to overcome the limits by facilitating user experience and VGI(Volunteered Geographic Information) in several geospatial web services. This study suggests 10C framework of geospatial web service for VGI through review and examination of previous research. Based on the 10C framework, the value chain system of 23 use cases relevant to the geospatial web service involving the creation of user's VGI is investigated. The result of the value chain analysis is applied to examine and formulate the strategies to generate value addition from public spatial information with respect to creation, aggregation, delivery, and consumption process of VGI.

Geospatial web services for limnological data: a case study of sensor observation service for ecological observations

Abstract. The present work aims at designing and implementing a spatial data infrastructure for storing and sharing ecological data through geospatial web services. As case study, we concentrated on limnological data coming from the drainage basin of Lake Maggiore in the Northern of Italy. In order to establish the infrastructure, we started with two basic questions: (1) What type of data is the ecological dataset? (2) Which are the geospatial web services standards most suitable to store and share ecological data? In this paper we describe the possibilities for sharing ecological data using geospatial web services and the difficulties that can be encountered in this task. In order to test actual technological solutions, we use real data of a limnological published study.We concluded that limnological data can be considered observational data, composed by biological (species) data and environmental data, and it can be modeled using Observation and Measurement (O&M) specification. With the actual web service implementation the geospatial web services that could potentially be used to publish limnological data are Sensor Observation Services (SOS) and Web Feature Services (WFS). SOS holds the essential components to represent time series observations, while WFS is a simple model that requires profiling. Both, SOS and WFS are not perfectly suitable to publish biological data, so other alternatives must be considered, as linked data.

Geospatial Service Platform for Education and Research

Abstract. We propose to advance the scientific understanding through applications of geospatial service platforms, which can help students and researchers investigate various scientific problems in a Web-based environment with online tools and services. The platform also offers capabilities for sharing data, algorithm, and problem-solving knowledge. To fulfil this goal, the paper introduces a new course, named "Geospatial Service Platform for Education and Research", to be held in the ISPRS summer school in May 2014 at Wuhan University, China. The course will share cutting-edge achievements of a geospatial service platform with students from different countries, and train them with online tools from the platform for geospatial data processing and scientific research. The content of the course includes the basic concepts of geospatial Web services, service-oriented architecture, geoprocessing modelling and chaining, and problem-solving using geospatial services. In particular, the course will offer a geospatial service platform for handson practice. There will be three kinds of exercises in the course: geoprocessing algorithm sharing through service development, geoprocessing modelling through service chaining, and online geospatial analysis using geospatial services. Students can choose one of them, depending on their interests and background. Existing geoprocessing services from OpenRS and GeoPW will be introduced. The summer course offers two service chaining tools, GeoChaining and GeoJModelBuilder, as instances to explain specifically the method for building service chains in view of different demands. After this course, students can learn how to use online service platforms for geospatial resource sharing and problem-solving.