Multi-data-source map download method

Abstract

The present invention provides a multi-data-source map download method. The multi-data-source map download method comprises: acquiring map coordinates of a downloading range; calculating pixel coordinates corresponding to a download level according to the map coordinates ; calculating a tile coordinate range and the number of slices (tiles) that needs to be downloaded according to the pixel coordinates; and splicing into a complete cache slice download address. Meanwhile, provided is a method for calculating the pixel coordinates corresponding to the download level according to the map coordinates while downloading a PGIS map cache slice by using the multi-data-source map download method. By the multi-data-source map download method, a WebGIS cache slice address is reversely analyzed and a map cache slice is downloaded to a local; and the method is suitable for providing base map base data and a download method for Web GIS application development.

Description

technical field [0001] The invention relates to the technical field of GIS, and is suitable for providing basic map base map data and a downloading method for WebGIS application development. Background technique [0002] With the increasing application of maps, the demand for map data is also increasing. However, data with accurate coordinates is a state secret, and individuals or companies without surveying and mapping qualifications cannot keep geographic data casually; on the other hand, the purchase price of geographic data Expensive. For projects that have not been officially purchased by users, the purchase of data will increase the expenditure of the project. Without data, the functions of map-based applications cannot be displayed. Based on this, map data has become a common bottleneck in the development of map applications. The network map data is encrypted, so there is no confidentiality problem. For projects that have not been implemented, or some map application...

AI Technical Summary

Problems solved by technology

[0002] With the increasing application of maps, the demand for map data is also increasing. However, data with accurate coordinates is a state secret, and individuals or companies without surveying and mapping qualifications cannot keep geographic data casually; on the other hand, the purchase price of geographic data Expensive. For projects that have not been officially purchased by users, purchasing data will increase project expenditures. Without data, the functions of map-based applications cannot be displayed

Based on this, map data has become a common bottleneck in the development of map applications

The network map data is encrypted, so there is no confidentiality problem. For projects that have not been implemented, or some map applications that only need a base map, the network map is the best choice. However, in many cases, the place where the project is applied It is not connected to the Internet, so you cannot directly use the Internet online map, so you must find a way to download the map to the local deployment

[0003] The existing map downloaders are basically paid, only the free download tool Daoge, there are some problems, such as using the form of data capture, relatively passive, slow download speed, can only download google maps, and often There will be missing data

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