01
Collect
Capture
GPS, survey, remote sensing and digitising.
Geographic Information Systems (GIS)
Geographic Information Systems
How points, lines and polygons become a living model of the world.
What is GIS
GIS links “where” with “what”.
A Geographic Information System is a framework for capturing, storing, managing, analysing and visualising data tied to locations on Earth.
It links where (coordinates) with what (attributes), so patterns, relationships and change can be seen and measured.
3Vector primitives
2Data models: vector, raster
4Dimensions of geometry, 0D to 3D
From Point to Volume
Every map is built from points, lines and polygons.
Each primitive adds one dimension to the last.
- Point0D · (x, y)
- Line1D · ordered vertices
- Polygon2D · closed ring with area
- Volume3D · polygon + height (z)
Point · 0D
A single coordinate pair.
- Wells, trees, sensors, addresses
Line · 1D
An ordered sequence of points, with length.
- Roads, rivers, pipelines
Polygon · 2D
A closed ring of lines enclosing an area.
- Parcels, lakes, administrative boundaries
Volume · 3D
A polygon given height, or a surface given depth.
- Buildings, terrain models, geological bodies
Two data models
Vector draws features; raster fills a grid.
| Model | What it stores | Best for | Formats |
|---|---|---|---|
| Vector Points, lines, polygons | Discrete features | Precise boundaries | Shapefile, GeoJSON, GeoPackage |
| Raster Grid of cells | A continuous grid; each cell holds a value | Elevation, imagery, temperature | GeoTIFF, COG |
Overlay
Layers stack on one coordinate system, so they align exactly.
GIS overlays thematic layers on a shared coordinate reference system (CRS), so every layer lines up with the others.
Common choices: WGS 84 · EPSG:4326 Web Mercator · EPSG:3857
Core operations
Capture, store, analyse, visualise.
02
Keep
Store
Spatial databases such as PostGIS.
03
Ask
Analyse
- Buffer
- Overlay
- Network routing
- Interpolation
- Spatial statistics
04
Show
Visualise
2D maps, 3D scenes and dashboards.
Where GIS is used
Anywhere location shapes a decision.
Urban planning
Zoning, land use and growth scenarios.
Environment & climate
Habitats, emissions and change over time.
Transport & logistics
Routes, networks and fleet movement.
Agriculture
Field boundaries, soils and crop monitoring.
Disaster response
Hazard zones, damage and access routes.
Utilities & infrastructure
Pipes, cables and asset networks.
Open-source toolkit
A full GIS stack, free and open.
Desktop & database
- QGIS Desktop
- PostGIS Database
Data & services
- GDAL/OGR Data conversion
- GeoServer Web services
Web & open data
- OpenLayers / Leaflet / CesiumJS Web maps & 3D globe
- OpenStreetMap Open data
GIS services
Remote GIS work, delivered on open-source tools.
Union OpenGIS helps small teams, consultancies and local agencies in North America turn location data into maps, analysis and web apps, without expensive licences.
Data cleanup & conversion
Shapefile, GeoJSON, KML, GeoPackage, CAD and CSV, reprojected, validated and fixed with GDAL and QGIS.
Geocoding & spatial analysis
Addresses to points, buffers, overlays, site selection, catchments and density studies, with a clear written summary.
Map production
Print-ready and report-ready maps for planning, real estate, environmental and permit documents.
Web maps & dashboards
Interactive maps with Leaflet, OpenLayers or CesiumJS, published on your site or hosted for you.
PostGIS & GeoServer setup
Spatial databases and WMS/WFS services installed, secured and tuned on your cloud server.
Ongoing support
Monthly data updates, map refreshes and server care on a simple retainer.
1. Send the brief
Email your data sample, the outcome you need and your deadline.
2. Fixed quote
You get a scope, a fixed price and a delivery date within one business day.
3. Delivery
Files, maps or a live link, plus one round of revisions included.
Start a project: admin@opengis.top