Webgis System Erection Scheme

Overview

The development of Internet technology, especially the appearance of online map, and the rapid penetration of lbs technology in all aspects of network and life, have led to the rapid development of the previously tepid Geographic Information system (GIS) industry. At present, the project scale of GIS industry is also expanding continuously. Includes basic map service function, software system with related industry business management, data management ability many will soar to tens. The three-dimensional GIS system is even more, only the data acquisition, the single province to calculate the basic is also in tens.

On the Webgis side, many people outside the industry are starting to get into contact with Google Maps API, or from the Google Maps API sample (in addition to the Google Maps API and the category of the Baidu Map API, the gold Map API). When we first approached the Google Maps API, all we had to do was to use the JS script to create a map object in the Web project's foreground page and link it to a div tag, where a map with the world, China and various roads appeared. When you add zoom in, zoom out, drag, query, scale, and so on to you, you can achieve a variety of features that Google Maps can use, a variety of cool. Here, perhaps you would say Webgis is so simple, what is the framework?

Yes, indeed, we can embed Google Maps in our apps where we can connect to the Internet, where we have normal access to Google services, where there is no special geographic data requirement. There are many such applications on the Internet. For example, tourism services, catering services, housing services, car rental services, social types, like eating, wearing, living, doing, with the map to marry. There are two questions here: 1. If I want to use my own geographic data, how do I combine it with a web system? 2. What should I do if my system is deployed in the internal environment?

In order to meet the above two problems, still can let our Webgis system run up. Depending on the source of the software used, there are 3 different architectures, a pure ArcGIS system, a pure open source system, and a hybrid setup scheme. A complete Webgis system that can be cut into 3 parts: Front interface + map/Data service + data. Next, we will explain the implementation of the 3 architectures from these 3 sections respectively.

The solution of pure ArcGIS system

ArcGIS is a product of ESRI, USA, and includes a complete solution from front-office to service release to data management. With more than 45 years of GIS field projects and research and development experience, as well as the company's efforts to implement the education industry donation activities, has become a highly efficient GIS in the field of professional software required. The system is fully architected using ESRI's software products.

The development of the page layer has a variety of optional technologies that support JavaScript (Dojo-based support), Flex, Silberlight. The service tier has two software-selectable ArcGIS Server and ArcGIS IMS, where ArcGIS server contains all the features of ArcGIS IMS. The data layer requires ARCSDE software and project-related geographic data.

The benefit of this architecture is that the extensive functionality of the ArcMap desktop software enables unified management of the service-tier software and data-tier software for ease and ease of use. Its disadvantage is that all software is commercial software, the project plan process needs to consider the purchase of software budget expenditure, for the small (million), commercial operation (non-prototype and experimental) system may not be very suitable, because the whole structure of the software required for the price of more than 500,000.

An approach to building a pure open source system

There are many open source projects in the field of GIS, which are said to be more than 200, which is the data from school in 2012. Unlike most open source projects the drawbacks must be said less technical data, there are technical risks, many GIS open-source projects have a strong team support, have perfect technical documentation, there are many successful experience, the same can easily find the introduction of the demo, quickly realize the start.

The Scenario page layer uses the widely used Openlayer, which is implemented using JavaScript technology, and can find enough help materials and sample code on the Web. The service layer uses GeoServer or map server, although the map server has more features than GeoServer, better performance, but because the use of research geoserver many people, in the problem solving can have a great advantage. The data tier recommends PostgreSQL, although MySQL also supports spatial databases, but some service tier programs are incompatible with MySQL, such as ArcGIS Server.

The advantage of open source is free, and it's a good choice for small projects. And, in the process of use, you may gradually start to focus on the underlying technology implementation, and enter the industry of Daniel. (A Distant Dream:))

Hybrid Erection Scheme

What I want to say is that the hybrid scheme has two meanings: 1. The use of technology in the 3 layer of mixed, such as the overall architecture of our current project, is in a transition period, from full reliance on the ESRI system to the open source system. As a result, there is no one-time overall jump in the process, but rather a gradual replacement of the 3 levels in the ESRI system from the database.

2. For the data basemap, it is often said that the tile map, generally it should be at least include the business area of the building, roads, rivers, etc., can be completely and Google Maps, Baidu map equivalent of things. This thing, if used in a way of buying, is a luxury choice for whatever type of project, sometimes we buy a map of Lourdes, or a map of Turing, and sometimes we also download Google Maps or other web-map tile data that can be downloaded from the Web. Then develop a Tomcat map service program to provide Web tile map services on your own.

Additional Information

Like the ESRI architecture of the first architecture scenario, there are a number of complete system software provided by a single company, such as the domestic super-map, the GIO, the foreign map Info, and the Ev-globe, and so on, that provide three-dimensional maps.

There may be projects where party a specifically requires the use of Webgis technology to implement a browser-accessible software system. However, here is a point to note is that the Web due to its existence of local file access issues, Webgis software does not support vector, remote sensing data editing problems, in the choice of whether to use Webgis or desktop GIS (standalone/standalone + Server), a simple consideration must be given to the need and webgis of this short board.