Adding External Data Sources to Maps: A Guide to Web Mapping Services

Web mapping services have revolutionized the way we visualize and interact with geospatial data. Whether you're a GIS professional, a developer, or a business looking to integrate location-based services, understanding how to leverage web mapping services like WMS, WFS, and WMTS can significantly enhance your mapping projects. In this article, we’ll explore the key web mapping standards, their benefits, and how to integrate external data sources into your maps using platforms like GISCARTA.

What Are Web Mapping Services?

Web mapping services are systems that store and deliver geospatial data over the internet, adhering to standards set by the Open Geospatial Consortium (OGC). These services enable users to access, visualize, and analyze spatial data dynamically. The most popular web mapping services include:

• WMS (Web Map Service)

• WFS (Web Feature Service)

• WMTS (Web Map Tile Service)

Each of these services has unique features and use cases, making them suitable for different mapping needs.

WMS (Web Map Service): Dynamic Mapping Made Easy

What is WMS?

WMS is an OGC standard that allows users to request and display map images from a remote server. It dynamically generates maps based on geospatial data, making it ideal for real-time applications.

How Does WMS Work?

WMS accepts client requests and generates map images based on specified data layers and display parameters. Users can customize scale, location, layer types, and other settings to tailor the map output.

Why Use WMS?

• Dynamic Mapping: WMS enables the creation of maps with complex display logic and layer overlays.

• Flexibility: Users can request maps on-demand without preloading all data.

• Standardization: WMS ensures compatibility with multiple data sources, simplifying integration.

When to Use WMS?

WMS is perfect for applications requiring real-time maps with dynamic content, such as traffic density visualization or object location tracking.

WMTS (Web Map Tile Service): High-Performance Mapping

What is WMTS?

WMTS is another OGC standard designed to deliver map data in the form of pre-rendered tiles. Each tile represents a small portion of the map, enabling faster loading and smoother navigation.

How Does WMTS Work?

WMTS divides maps into small image tiles, which are served to clients upon request. These tiles can be cached on the client or server side, significantly improving performance.

Why Use WMTS?

• Enhanced Performance: Tile-based maps load quickly, even when navigating large areas.

• Caching: Tiles can be cached, reducing server load and speeding up map rendering.

When to Use WMTS?

WMTS is ideal for high-traffic applications, such as mobile web maps or tourist services, where performance is critical.

WFS (Web Feature Service): Interactive Vector Data Management

What is WFS?

WFS is an OGC standard for exchanging vector data. It allows users to query, edit, and update geospatial data in formats suitable for analysis.

How Does WFS Work?

WFS provides access to geometric and attribute data for vector features like points, lines, and polygons. Data can be delivered in formats like GML (Geography Markup Language).

Why Use WFS?

• Interactive Data Editing: WFS supports adding, deleting, and modifying vector data.

• Spatial Data Retrieval: Users can query specific objects and retrieve up-to-date information.

When to Use WFS?

WFS is invaluable for applications involving vector data analysis and management, such as urban planning or natural resource monitoring.

How to Add External Data Sources to Maps in GISCARTA

Integrating external data sources into your maps is straightforward with GISCARTA. Follow these steps to enhance your mapping projects:

Step 1: Access Data Sources

1. Navigate to the Data Sources section in GISCARTA.

2. Click the Upload Data button in the top-right corner.

Step 2: Choose Your Data Source

You have two options:

• Upload from your computer.

• Link to an external data source via URL.

For this guide, we’ll focus on linking external data sources.

Step 3: Connect to External Services

1. Select the service type: GeoServer, ArcGIS Server, or External WMS/WMTS.

2. Enter the service URL. For example:

• ArcGIS Server: https://sampleserver6.arcgisonline.com/arcgis/rest/services/

• GeoServer: https://mrdata.usgs.gov/services/ofr20051294/

3. Click Connect to connect and retrieve the list of available services.

4. Select the layers you want to save in your data source.

Step 4: Add Metadata

Optionally, add a Description and Tags to make your data easier to find and navigate.

Step 5: Add Data to Your Map

Once connected, your external data source will be available in the Data section of the menu. You can now add it to your map project.

It’s important to mention that WMS layers will be added to a map with their styles. And WFS layers can be styled in your project.

WMS Layer example:

WFS Layer example:

Conclusion

By leveraging web mapping services like WMS, WFS, and WMTS, you can create dynamic, high-performance maps enriched with external data sources. Platforms like GISCARTA make it easy to integrate these services, enabling you to build complex and visually stunning maps for a variety of applications. Whether you're tracking real-time data or managing vector datasets, these tools empower you to take your mapping projects to the next level.