Programming Panning and Zooming in Interactive Maps

Due to a growing appreciation for the ecological and recreational benefits of public green spaces, the evaluation of urban parks’ service efficiency, as well as citizens’ behavioral preferences for daily recreation, have become an increasing academic focus. However, due to the lack of empirical approaches, existing research on exploring park service areas has been simplified by their use of Euclidean distance or buffer sets by simulation, ignoring the fact that the likelihood of citizens visiting urban parks is time sensitive. Utilizing mobile signaling data and web map services, this study proposes an approach to estimating the travel times of park visitors and analyzing the characteristics of park service areas from the perspective of actual time consumption. Taking Shanghai as a case study, this research firstly identified the time–cost decay of parks with different areas and locations. A comparison analysis was then used to examine the spatial relationship between park service areas and their accessibility defined by time consumption. The results show that (1) urban parks in Shanghai have larger mean service radii than existing planning guidelines, and park service areas were significantly influenced by park locations; (2) people have a great preference for urban parks whose travel times by public transit are under 40 min, and they have no desire to visit parks located within or outside the Middle Ring Road when the travel times reach 60 min and 75 min, respectively; (3) the shapes of park service areas are consistent with the high-accessibility districts defined by time thresholds, in spite of some differences caused by citizens’ choices. These findings provide an effective tool for evaluating the actual characteristics of park recreational services, along with direct implications for policymakers aiming to establish effective strategies for improving the accessibility and vitality of urban parks.

Today, interactive maps are gaining popularity and are used by both specialists and ordinary users in various fields of science and technology. However, the development of the theoretical base of web cartography and the development of interactive maps lags significantly behind the practical component. Moreover, a systematization of the principles of user-centered design in the field of web mapping is necessary. The aim of this work is to create a methodical framework that can be universal for most interactive web map development projects. The creation of the framework is based on the established scheme of interactive web maps development, the ideas of user-oriented design, as well as on the personal experience of the authors in the development of interactive web maps. The methodical framework covers the following aspects: the need for interactivity of web maps, accessibility on various devices, the dimensional aspect of a map, data structuring, the choice of elements of interaction, the need of usage of third-party maps, multilinguality, the ability to upload user-generated content, the need to create animations, and the choice of the base software. The developed framework helps to form the determining part of the conception of an interactive web map, which is a fundamental step in the proposed process of a web map development. Moreover, the framework facilitates the process of creating interactive web maps and opens up new possibilities and development methods for specialists in web cartography. The authors, using the interactive web map dedicated to the World Heritage Site “Struve Geodetic Arc”, which was developed by them, as an example, clearly demonstrated the conceptual development process based on the methodical framework. The terminology is considered and a new definition of an interactive web map is given.

Recent advances in open geospatial web service, such as Web Map Service as well as corresponding web ready data processing service, have led to the generation of large amounts of OGC enabled links on Internet. How to find the correct spatial aware web service in a heterogeneous distributed environment with some special criteria, such as coincidence of type, version, time, space and scale has become a "bottleneck" of geospatial web-based applications. In order to improve the accessing precision of OGC Web Map Service (WMS) on WWW, a new methodology for retrieving WMS based on extended search engine and service capability match is put forward in this paper. Major components include the WMS search engine, WMS ontology generator, WMS catalogue service and multi protocol WMS client. Here we proposed the architecture and interaction between these components before focusing on the service capability match and design of the WMS ontology. The process of WMS link detection, capability matching, ontology modeling, and automatic registry are reported in this paper. Then the precision and response time of WMS retrieval is evaluated, results show that the mean execution time during per effective hit of proposed method is 0.44 times than that of traditional method, moreover, the precision is about 10 times than that of traditional method. WMS ontology record could be generated by ontology reasoning, registered and served by CSW.

The Web Map Server Implementation Specification (WMS), originally developed and published by the Open Geospatial Consortium, was finally adopted by ISO as an international standard. According to this standard maps are presented either in picture formats or formats. While the pictorial (visual) representation uses raster formats, graphic element formats include Scalable Vector Graphics (SVG) or Web Computer Graphics Metafile (WebCGM) format. In this paper a framework for supporting Web Map Services using SVG will be presented. Geo-data, converted to SVG, is stored in a database management system, retrieved by the WMS server upon user request and transferred - optionally compressed - through the Internet. Finally it is visualized in Web browsers on desktop computes or mobile devices, natively or using plug-ins extending the browser's functionality. Besides supporting the WMS request GetCapabilities, GetMap and GetFeatureInfo requests, additional formats and extensions have been included in this framework. The development proves that open, XML-based standards in combination with modern programming languages and integrated development environments allow rapid implementation of recommendations and standards in geo-informatics.

The geographical location and tourist features of St. Petersburg require a specialized web service for owners and tenants of river transport, aggregating all the information necessary for them. Currently, such information is available in various news sources, web portals and groups in social networks. The work presents a prototype of a service for small river transport users. Information needs and functional and requirements for it were identified during in-depth interviews with stakeholders of the project. The web service database is implemented in the PostgreSQL DBMS with the PostGIS extension. The work presents the structure of the service, which includes 10 pages, describes its main sections, such as current regulatory documents, news, interactive maps, reference information, as well as technical information about ships and restrictions on their movement due to technical characteristics. During its development, an analysis of existing solutions related to each section was carried out. During the "Maps" section development, an analysis of existing web tools for displaying interactive maps and the selection of the best solutions was carried out. Using the Google Maps designer, interactive maps were created for the web service being developed. The first of them is a map of the city's water bodies, containing such layers as: floating gas stations, lighthouses, customs, checkpoint and Ministry of Emergencies, private yacht clubs and marinas, berths and quayes, bridges, etc. The interactive weather map allows the user to get acquainted with the weather conditions, as well as their 5-day forecast. One of the priority functional requirements of the web service, called stakeholders, was the determination of water barriers and bridges that were inappropriate in the size of the vessel. The "Your Ship" section of the developed prototype web service offers a solution to meet this requirement. The developed web service is one of the favorable incentives for the development of the water tourism sphere and the use of river transport in St. Petersburg.

• A data service system for the selected SMAP data and its derivative data products over CONUS is developed. • All map and geoprocessing services are implemented via the OGC standard interface. • The data service system is interoperable with web and desktop clients. • Monitoring and analyzing U.S. cropland soil moisture conditions are significantly simplified. Soil moisture is an essential parameter to understand crop conditions throughout the growing season. Collecting soil moisture data by field observation is labor-intensive, especially when attempting to obtain Conterminous United States (CONUS) geographic coverage. In addition, using soil moisture for assessing current and future crop conditions is best realized by combining soil moisture estimates with concurrent observations of crop conditions. However, until recently, this capability has not been available to the public. In this paper, we present an interoperable data service application system, the Crop Condition and Soil Moisture Analytics (Crop-CASMA) system, that facilitates the retrieval, analysis, visualization, and sharing of soil moisture data for the CONUS. This system delivers a variety of satellite remote sensing based data products that are derived from Soil Moisture Active Passive (SMAP) Level-4 data and SMAP Thermal Hydraulic disaggregation of Soil Moisture (THySM) data, as well as vegetation index data derived from Moderate Resolution Imaging Spectroradiometer (MODIS) observations. To make services interoperable and reusable, all data products are disseminated via Open Geospatial Consortium (OGC) Web Map Service (WMS) and Web Coverage Service (WCS) interface standards. Additionally, a suite of geoprocessing operations, such as geospatial statistics, time-series profile generation, PDF map production, and image composition, has been implemented in the OGC Web Processing Service (WPS) interface standard. The implementation shows the proposed web service system can significantly simplify the mapping and quantitative analysis of soil moisture and crop condition over U.S. cropland. In addition, it is interoperable with GIS software and has been successfully integrated with web-based applications.

A neural network based intelligent system for tile prefetching in web map services

Abstract. The current task of cartographic support for geological exploration and the oil and gas industry is to meet the needs for rapid access to spatial data by specialists. The preparation of specialized data for publication in interactive web maps involves a number of technical issues. Some of them are explored in detail in case of a cartographic support for a cameral processing and interpretation of geological, geophysical and other geoscientific data in Andaman deep water basin. The points highlighted here are in fact a reflection of the role of interactive web maps, regardless of the thematic content, in the development of the Real and Virtual maps concept. The experimental work presented in this article illustrates most of the R/V transformations first developed by H. Moellering in early 1980s. Solving the operations for transformations between real maps, interactive maps, initial (raw) thematic data and cartographic databases will help enrich cartography with new methods of creating and using data, expanding and adapting the communicative conception of cartography to modern realities. An example of the web map developed also shows how the cartographer can simplify the work of professionals in other sectors, their communication with each other through the map language and its web representations. The use of web maps in the poorly studied Andaman deep water basin shows how web maps can contribute to the quality implementation of government programs for increasing exploration and the subsequent development of mineral resources.

Take open source GeoWebCache tile map service middleware as an example, through analysis of its basic principle and system architecture, this paper give three optimization strategies which are tile spatial index, extension mechanism and the deployment strategy. Finally, we make a performance comparison between GeoWebCache and traditional OGC (Open Geospatial Consortium, OGC) standard WMS(Web Map Service). Our experimental results show that the average response time of GeoWebCache reduced by 36% than sending WMS request to WMS server directly. The study shows that GeoWebCache middleware has important application value both in improving traditional WebGIS performance and in upgrading existing legacy systems.

The precise and accurate performance of location estimation is a vital component of context-aware applications. Numerous mobile devices with built-in IEEE 802.11 Wi-Fi technology can be used to estimate a user's location through a wireless local area network (WLAN) in indoor environments in which fixed access points are deployed. This study deals with improving the common techniques of such positioning once the acquisition of the fingerprint database in offline phase is performed. The main idea is to propose a methodology that includes two layers of classification: a concurrent hierarchical partitioning of both signal and physical space in a way that signal patterns in each part of building have the highest similarity, and a precise and independent positioning in a given part. A procedure for combining the proposed classifier with either artificial neural network (ANN) or Bayesian probabilistic model is then introduced. We also consider an alternative strategy for ANN learning by including all raw observations. The average distance error was successfully reduced in the proposed methodology by 32 % compared to the simple approach. We concluded that the physical partitioning should also consider the signal behavior. Toosi location-aware mobile system was ultimately implemented, providing different services (e.g., friend finder and nearest point of interest) based on the proposed technique via WLAN. The system benefits from the high level of interaction provided by Asynchronous JavaScript and XML (AJAX) technology. It is capable of transferring locational data and GIS map services efficiently to the mobile terminal.

Android platform is a new generation of smart mobile phone platform launched by Google. Android provides the support of mobile map and location service, which is probably a concern of vast numbers of developers. So far, the development of mobile map and location applications is complex and difficult, and is often required to pay high copyright fees to map makers. Android is free and open, providing an easy-to-use development kit containing flexible map display and control functions. This paper introduces the architecture and component models of Android, and analyzes the anatomy of an Android application including the functions of Activity, Intent Receiver, Service, Content Provider, and etc. Based on Android, the design method of a location-based mobile service is then presented. The design example shows that it's so easy to implement self-location, to draw the driving trace, to perform query and to flexibly control the real-time map on Android.

Web map service is a new map service mode actualized by the use of internet technology, computer technology and GIS technology. This article applies Web map service to the release of land use information, and tries to use Google Maps API and XML to build a network release system of regional land use information. The system integrates Google Maps data and user data effectively, carries out the display and management of land use information, and has a powerful public participation function. This study shows that Web map service based on Google Maps API and XML can play an important role in the release of land use information, which is also important in the information-based construction of land resources.

This paper characterizes the requirements of geographic information systems (GIS) middleware and its components for dynamic registering and discovering of spatial services specifically for collaborative modeling in environmental planning. The paper explores the role of Web services with respect to implementation standard and protocols and identifies implementation features for exposing distributed GIS business logic and components via Web services. In particular, the paper illustrates applications of the interoperability specifications of Open GIS Consortium’s (OGC) Web mapping service and (WMS), Web processing standards (WPS) with respect to implementation feature. The paper demonstrates a prototype implementation of collaborative environmental decision support systems (GEO-ELCA- Exploratory Land Use Change Assessment) where Web service-enabled middleware adds core functionality to a Web mapping service. The application demonstrates how individual workspace-based namespaces can be used to perform Web mapping functionality.

The spread of geobrowsers as tools for displaying geographically referenced information provides insights and opportunities to those who, not being specialists in Geographic Information Systems, want to take advantage from exploration and communication power offered by these software. Through the use of web services such as Google Maps and the use of suitable markup languages, one can create interactive maps starting from highly heterogeneous data and information. These interactive maps can also be easily distributed and shared with Internet users, because they do not need to use proprietary software nor special skills but only a web browser. Unlike the maps created with GIS, whose output usually is a static image, the interactive maps retain all their features to users advantage. This paper describes a web application that, using the Keyhole Markup Language and the free service of Google Maps, produces choropleth maps relating to some forest indicators estimated by the last Italian National Forest Inventory. The creation of a map is done through a simple and intuitive interface. The maps created by users can be downloaded as KML file and can be viewed or modified via the freeware application Google Earth or free and open source GIS software like Quantum GIS. The web application is free and available at www.ricercaforestale.it.

Knowledge sharing and semantic interoperability is a significant research theme in Geographical Information Science (GIScience) because many researchers believe that semantic heterogeneity has been identified as the main obstacle for GIScience development. Interoperability issues can exist at three levels: syntactic, structural (also called systemic) and semantic. The former two, however, can be achieved by implementing international or domain standards proposed by several organizations, for example, Open Geospatial Consortium (OGC), World Wide Web Consortium (W3C) and the International Organization for Standardization/Technical Committee for Geographic information/Geomatics (ISO/TC 211). In this paper, we are concentrating on semantic interoperability, which is the sort of topic that halt conversations and cause people's eyes to glaze over, from two aspects: data/information/knowledge and operation/processing. We presented a service-centered architecture for semantic interoperability of geospatial data and processes. OGC standards like Web Feature Service (WFS) and Web Map Service (WMS) have been employed as normative interfaces for analyzing requests, division requests and delivering small requests. Ontology has been introduced to describe distributed resource including various data and geo-processing operations. The role of interoperability, especially from semantic perspective, has been distinguished at the first section in this paper. As a fundamental principal, the following section introduces semantic web, web service and other related works at this orientation. We present our service-based architecture in detail and its simple application at part three. Conclusion and further orientations have been illustrated at last section.