Skip to main content

GeoServer Web Services

Qarta provides direct access to a fully-featured GeoServer instance through OGC-compliant Web Services (WMS and WFS). These services allow you to interact with geospatial layers published in GeoServer using industry-standard protocols.

What is GeoServer?​

GeoServer is an open-source server for sharing geospatial data. It implements the OGC (Open Geospatial Consortium) standards:

  • WMS (Web Map Service) — render styled map tiles
  • WFS (Web Feature Service) — query raw geographic features

The Qarta proxy sits in front of GeoServer, adding authentication (API key) and making these services accessible as part of the unified Qarta platform.

Authentication​

All GeoServer endpoints are accessed through the standard Qarta authentication:

Authorization: YOUR_API_KEY

Pass your API key in the Authorization header as you would for any other Qarta endpoint. The API key is validated, then the request is forwarded to GeoServer.

API key must stay on the server

Browser-based map libraries (Leaflet, OpenLayers, Mapbox GL) cannot set custom HTTP headers on WMS/WFS tile requests. Do not expose your API key in client-side code.

For web applications that embed WMS tiles or query WFS data, run a backend proxy that attaches the API key before forwarding requests to Qarta. See the GeoServer Proxy Guide for a complete, runnable Python example.

Base URL​

All Web Services are accessed via the /graph/layers/ base path:

https://graph.quarticle.ro/graph/layers/

Layer Naming Convention​

Layers in GeoServer follow the WORKSPACE:layername format:

  • WORKSPACE: typically GRAPHRASTER for imagery-based layers
  • layername: the specific layer (e.g., light_pollution, temperature, elevation)

Example: GRAPHRASTER:light_pollution

Coordinate Systems​

Map Tiles (WMS)​

Map tiles are typically requested in EPSG:3857 (Web Mercator), the standard web projection:

srs=EPSG:3857
bbox=975947.9771,6657970.9118,1533632.5355,7037098.5720

Feature Data (WFS)​

Raw features are typically returned in EPSG:4326 (WGS84, lat/lon), the global standard:

srsName=EPSG:4326

Available Services​

WMS — Web Map Service (5 operations)​

Render styled map tiles from GeoServer layers. Use this to:

  • Display layers on an interactive map (Leaflet, OpenLayers, Mapbox)
  • Generate static map images
  • Query features at a pixel location on a map
  • Retrieve layer metadata and legends

👉 Read the WMS Guide

WFS — Web Feature Service (1 operation)​

Query raw geographic features from GeoServer layers. Use this to:

  • Download features as GeoJSON or GML
  • Filter by bounding box, feature ID, or CQL expression
  • Select specific properties
  • Integrate feature data into applications

👉 Read the WFS Guide

Use Cases​

Map Visualization​

Embed WMS layers as overlays in web maps to display styled geospatial data alongside other map elements.

👉 See: Map Visualization Use Case

Feature Querying​

Retrieve raw geographic feature data for analysis, export, or downstream processing.

👉 See: Feature Querying Use Case

GeoServer-Specific Features​

CQL Filters​

GeoServer extends the OGC standard with CQL (Common Query Language) for powerful attribute and spatial filtering:

cql_filter=population > 1000000 AND type = 'urban'
cql_filter=INTERSECTS(geometry, POINT(-74.0060 40.7128))

Styled Layer Descriptor (SLD)​

Define custom map styles using SLD, an XML-based styling language, or reference pre-defined styles published in GeoServer.

Time Support​

Some layers may support temporal queries using the time parameter:

time=2023-01-01T00:00:00Z
time=2023-01-01T00:00:00Z/2023-12-31T23:59:59Z

Security & Limits​

  • Authentication: All Web Services endpoints require your API key
  • Data access: Only layers published in GeoServer are accessible
  • IP whitelisting: May be enforced at the GeoServer level (contact support if needed)

Next Steps​