Discussion on the open source GIS solution of our company

• In line with our company GIS Discussion on open source solution

1. Preface

This week , I am right. GIS Open source solutions involved in the open source software and related technologies and processes to do some preliminary exploration , I also learned about the mature cases of other companies using open source solutions . Here I will summarize the pre research of some key technical points , At the same time, it makes an analysis of the successful open source cases of other companies , And I think the most suitable for the actual situation of the company at present GIS Open source solutions .

2. Pre research on key technology points

2.1 Spatial data storage （postgreSQL+postGIS）

utilize postGIS take shp Data import to postgreSQL in ：

2.2 Spatial data editing (uDig)

Import postgreSQL Spatial data in , It can display and edit .

2.3SLD The making of style file

Can be used directly uDig Map layers and produce corresponding SLD file , And you can export ：

2.4 utilize geoserver Release postGIS Spatial data in

stay Geoserver Add stores choice postgis that will do ：

2.5 utilize Geoserver Publish layer groups

Combine multiple layer services published separately into one layer group , The layers under all layer groups can be displayed in one request ：

Layer groups that contain cell grids and communities ：

2.6 utilize GeoWebCache Cut cache

Studied GeoWebCache There are two kinds of clipping strategies ： One is class AGS Cut strategy , That is, cut in advance ; One is class AGS Dynamic cut strategy , That is, the first time the request cuts .

The configuration and result of the cut graph ：

2.7 Yes, use postGIS Medium ST_Geometry Function for the pre research of spatial data management and spatial analysis

PostGIS Medium ST_Geometry Function and SDE It's basically the same in , But it includes some of its own extension functions . It has the following functions ：

stay postgresql Test the basic spatial elements of the addition, deletion, search and change, as well as spatial elements of the area and length of access ：

3. A case study on the maturity of other companies

The safety of a company XX（ Security projects ） As the case object of this study , By communicating with their R & D staff , I get the following information ：

3.1 Adopt a framework

Geoserver（ Map server ）+geoWebCache（ Tile cache service ）+JBOSS（ middleware ）+postgreSQL（ Spatial database ）+Oracle（ Business database ）+uDig( Spatial data editing tools ).

3.2 Some analysis points of the project are summarized

a. In this project Geoserver Released nearly 60 layers , No obvious instability .

b. Spatial data query in the project 、 Editing and spatial analysis functions involved , All use ST_Geometry Function implementation , Good efficiency .

c. Map tile cache used in the project geoWebCache Dynamic mapping strategy of . Nearly 60 layers are used as base maps , The time of the first request for drawing is about 20 More than a second （ Add in the cost of the Internet ）.

d. Business data and spatial data are stored separately , Business data is stored in Oracle in , The spatial data is stored in postgresql in .

e. Project deployment , Research and development for them, after all the data are processed in advance , And then put the... That already contains the data Geoserver And the space library to the field engineers .

3.3 Personal evaluation of the project

3.3.1 advantage

a. The functions of drawing and spatial analysis are basically complete , Efficiency and stability are also good . Safety XX It is a relatively large project in itself , Experienced a better practice test .

b. The spatial analysis is applied to ST_Geometry+SQL To achieve , Not through Geoserver Provided by itself WFS service , There can be more customization requirements , And if there's a mistake, it's easy to check . If it's written properly , It can speed up data acquisition . meanwhile , Not GIS It's easier for professional developers to understand .

c. Separate spatial data from business data , This can ensure that the original business data used in other projects will not change much , Ensure the stability of the system .

3.3.2 shortcoming

a. The implementation of the project requires the participation of R & D personnel , Put data in storage and publish . And then we have to cooperate with the site to arrange the environment .

3.4 What remains to be proved

a. When used geoWebCache When making a cut , If the base map is complicated , Whether it can guarantee the cut without distortion .

b. When used GeoWebCache When making a cut , If the base map is a large image （GB above ）, Whether it can guarantee the cut without distortion , And the efficiency of the first drawing .

c. When used Geoserver Publish more than 100 When you use a layer service ,Geoserver The stability of itself .

4. In line with the company's open source solutions

Through the above pre research of key technology points and the analysis of successful cases of other companies , Combined with the current overall structure of the company , I personally propose an open source solution that I think is more in line with the company ：

GeoServer（ Map service ）+ Local tile service （ArcGIS Isometric diagram ）+Tomcat（ middleware ）+Postgresql（ Spatial database ）+Oracle（ Business database ）+uDig（ Spatial data editing tools ）.

4.1 Detailed system architecture explanation

4.1.1 Underlay cache service

Companies can still use ArcGIS To make a cut （ The company has a genuine ）, There are three benefits ：

a. Project implementers are easy to operate .

b. It's easy to map .

c. It can ensure the quality and efficiency of cut .

The cut picture , We can use our existing offline tile strategy , Bypass GeoWebCache The adoption and configuration of . Of course , If you don't want to use ArcGIS Cutaway , I want to open source completely , We can also study the use of MapTiler This open source cutting tool , The efficiency and effect of the cut is quite good .

4.1.2 Dynamic drawing of components （WMS）

Adopt the company's existing technology based on GeoServer The function of .

4.1.3 Vector query （WFS）

Adopt the company's existing technology based on GeoServer The function of .

4.1.4 Spatial analysis function （WFS）

For those who have passed GeoServer Spatial analysis function of development , It can be based on the adoption of . For the undeveloped part , The proposal USES ST_Geometry Function to do .

4.1.5 Spatial database

use postgresql+postGIS.PostGIS Support batch warehousing , It also supports Chinese data , Very good stability and performance , It's easy to operate . meanwhile , There are also many development tutorials and community forums .

4.1.6 Data editor

use uDig To edit spatial data .uDig You can import shp Data or postgis Data in , Can also be shp Data import to postgresql in . It also supports data style editing and SLD File generation .

4.2 Implementation of the project

a. The cutting link project can be completed by itself .

b. The input of spatial data can also be realized through postGIS Do it yourself , Operation heel catalog It's just as easy to operate .

c. Publishing spatial data and associating basic styles of components , And the generation of business data , It can be realized by modifying the existing gadgets .

d. Configuration and release of complex styles , It can be done with the help of R & D .