Georeferencing: How devices (including smartphones) turn images into GIS data

Written by
Brooke Hahn
June 26, 2024

We use smartphones for pretty much everything these days. But did you know they can be used for capturing ground-based GIS data, along with devices like drones and 360 degree panoramics? It’s all thanks to the georeferenced information stored within the captured imagery.

What is georeferenced imagery?

Georeferenced imagery refers to images that are tied to specific geographic locations on the Earth's surface. These images come with embedded geographic coordinates (latitude and longitude), often obtained using GPS (Global Positioning System) technology, enabling them to be accurately placed on a map. This transforms raw images into valuable spatial data that can be used for various applications, from urban planning, facilities management, and environmental monitoring, to disaster response.

The basics of geographic coordinates

Latitude and longitude 

Geographic coordinates, specifically latitude and longitude, are used to define locations on the Earth's surface. Latitude measures how far north or south a point is from the Equator, while longitude measures how far east or west a point is from the Prime Meridian.

Some interesting coordinates:

  • Eiffel Tower, Paris, France - Latitude: 48.8584° N Longitude: 2.2945° E
  • Pyramids of Giza, Egypt - Latitude: 29.9792° N Longitude: 31.1342° E
  • Sydney Opera House, Sydney, Australia - Latitude: 33.8568° S Longitude: 151.2153° E
  • Niagara Falls, Canada/USA Border - Latitude: 43.0962° N Longitude: 79.0377° W
  • Machu Picchu, Peru - Latitude: 13.1631° S Longitude: 72.5450° W

Coordinate systems and projections 

To accurately place georeferenced imagery on a map, we use coordinate systems and map projections. Coordinate systems provide a framework for defining locations, while map projections translate the Earth's curved surface onto a flat map, ensuring spatial accuracy.

How georeferencing works

Geotagging 

Geotagging is the process of embedding geographic coordinates into an image at the time of capture. This is commonly done using devices with GPS capabilities, such as smartphones and cameras. When you take a photo with your smartphone, it can automatically record the location, creating a geotagged image.

Manual georeferencing 

For images without embedded coordinates, manual georeferencing can be done using control points and reference maps. This involves identifying known locations within the image and matching them to corresponding points on a reference map to assign accurate geographic coordinates.

Visualizing georeferenced imagery in Birdi

You can visualize any georeferenced imagery in Birdi; whether it’s captured from drones, satellite, 360 degree panoramic or smartphone. 

Upload your georeferenced images 

Once you've created a map in your Birdi workspace, upload your georeferenced imagery.

Visualize your georeferenced images in Map View

Birdi recognizes the geographic coordinates embedded in your images and places them accurately on the map, precisely where they were captured from. This gives you comprehensive spatial representation of your sites and locations of interest.

Processing, analysis and insights

From there, you can use our variety of tools to gain insights into your geospatial data. You can assess your images for faults and issues, you can process your drone imagery into outputs such as orthophotos, DEMs, contours, and 3D models (note: you wouldn’t use ground-based data such as that captured by smartphones for mapping purposes, you’d need top-down imagery captured from above by drones), as well as use our reporting and annotation tools for further insights.

Sharing and collaboration 

You can share maps easily through Birdi. Whether collaborating with a team or presenting findings to stakeholders, Birdi ensures your georeferenced imagery is accessible and understandable.

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Devices equipped with GPS functionality turn regular images into GIS data. And with platforms like Birdi, you can easily visualize and analyze your data precisely where it was captured from, helping you to make informed, data-driven decisions.

Brooke Hahn
Brooke has been involved in SaaS startups for the past 10 years. From marketing to leadership to customer success, she has worked across the breadth of teams and been pivotal in every company's strategy and success.