An easy glossary of geospatial and GIS terms

Written by
Brooke Hahn
October 17, 2024

If you’ve ever come across terms like “geospatial data,” “DEM,” or “point cloud,” and wondered what they mean, you’re not alone. The world of Geographic Information Systems (GIS) and geospatial technology is filled with jargon that can feel overwhelming if you’re new to the field. But don’t worry — we’re here to break it all down for you, no degree in cartography required.

This guide walks through some of the key terms, providing simple explanations to help you feel more confident the next time you encounter them. Let’s dive in!

Geospatial data

At its core, geospatial data is information that has a location tied to it. This could be the coordinates of a specific building or the outline of a country’s borders. It's what helps us map and understand physical spaces.

Example: Imagine you’re looking at a map of your city on your phone. The streets, parks, and restaurants displayed are all examples of geospatial data — they exist in a specific location on Earth.

GIS (geographic information system)

A geographic information system (GIS) is the tool used to analyze, store, and visualize geospatial data. Think of it as the brain behind the map. GIS can combine layers of data like topography, population density, or vegetation to help us make better decisions, whether it's for urban planning, environmental monitoring, or even disaster response.

Example: A city might use a GIS to plan where new schools or hospitals should be built by analyzing population growth and accessibility.

GPS (global positioning system)

We’re all familiar with GPS — it’s what powers the location services on your phone or the navigation system in your car. GPS is a satellite-based system that tells you exactly where you are on the globe, by providing coordinates like latitude and longitude.

Example: When you use Google Maps to get directions, GPS is what provides your real-time location on the map.

Remote sensing

Remote sensing refers to the process of gathering data about the Earth’s surface without physically touching it. Typically, this is done using satellites or drones, which capture images and data from the air or space.

Example: Satellites orbiting the Earth can collect images of forest coverage over time to monitor deforestation or track changes in sea levels.

Orthomosaic

An orthomosaic is a super-precise map made by stitching together a bunch of aerial images, often taken by a drone. It’s geometrically corrected, meaning you can measure distances and areas accurately on it.

Example: Companies in construction often use orthomosaics to create up-to-date maps of a site as work progresses, ensuring that everything is on track.

DEM (digital elevation model)

A digital elevation model (DEM) is a 3D representation of a landscape’s surface, showing you the highs and lows of the terrain. This is used in everything from flood risk assessments to creating video game landscapes.

Example: Think of a DEM like a 3D topographic map. It helps engineers design roads that avoid steep inclines or flood-prone areas.

Contour lines

You’ve probably seen contour lines on a topographic map. These wavy lines show the elevation and shape of the land. The closer together the lines are, the steeper the terrain.

Example: If you’ve ever gone hiking, those contour lines on your map tell you how hard the climb will be. Lines packed closely together mean it’s going to be a steep ascent!

Point cloud

A point cloud is a collection of 3D data points that are used to model a surface or object. Drones, LiDAR (Light Detection and Ranging), or photogrammetry software often generate these clouds, and they’re particularly useful for creating detailed 3D models.

Example: In construction, point clouds are used to capture highly detailed 3D models of buildings and infrastructure for design verification or progress monitoring.

Georeferencing

Georeferencing is the process of aligning spatial data (like an image or map) with a specific location on Earth. This makes sure that when you overlay one layer on top of another in a GIS, they match up perfectly.

Example: You could take an old paper map, scan it, and georeference it so it lines up correctly with modern satellite imagery in a GIS platform.

Geodatabase

A geodatabase is just like a regular database, but it stores spatial data. It’s where all your maps, layers, and location-based information are kept when working in GIS.

Example: If you were working on a city planning project, your geodatabase might contain layers for roads, buildings, and parks — all neatly organized in one place.

Layer

In GIS, a layer is a set of data that you can view separately or combine with other data. For instance, you might have one layer showing the streets of a city and another layer showing the locations of hospitals. By layering them together, you can analyze how accessible hospitals are from different parts of the city.

Example: Layers work like transparencies you can stack on top of each other, letting you view different types of data in one map.

Raster data vs. vector data

These are the two main types of geospatial data formats: raster and vector data.

  • Raster data is made up of pixels or cells. It’s like a digital photo — think satellite images or digital scans of old maps.
  • Vector data uses points, lines, and polygons to represent features. This data is more like a drawn map where roads are lines and buildings are shapes.

Example: If you wanted to map a forest, raster data might show a satellite image of the area, while vector data would define the exact outlines of trees and paths.

LiDAR (light detection and ranging)

LiDAR is a remote sensing method that uses laser pulses to measure distances to the Earth. This creates highly accurate, high-resolution 3D models of the terrain.

Example: LiDAR is used in self-driving cars to detect nearby objects, or in forestry to measure tree height and canopy density.

GCP (ground control point)

A ground control point (GCP) is a specific point on the ground with known coordinates. It’s used to improve the accuracy of drone mapping and geospatial data by ensuring that what you see in the images matches up with real-world positions.

Example: In construction, GCPs help drone maps line up perfectly with ground features, so measurements for building sites are precise.

UTM (universal transverse mercator)

The UTM is a system of dividing the world into a grid to make mapping easier. It uses meters instead of degrees to measure locations, which can be more practical for some types of work.

Example: While latitude and longitude tell you where you are in degrees, UTM tells you your exact position in meters on a flat grid — much easier for engineers!

Attribute data

Attribute data describes the characteristics of geographic features. In a GIS, it’s the additional information about a feature that helps provide context. For example, a road might have attribute data that tells you its name, speed limit, or whether it's a one-way street.

Example: Attribute data is what allows you to click on a point on a map and get detailed information, like the type of tree species in a park.

Spatial analysis

Spatial analysis refers to the process of analyzing geospatial data to answer questions or solve problems. It involves using GIS to detect patterns, trends, and relationships in spatial data.

Example: A city might use spatial analysis to determine where to build new bike lanes by analyzing traffic flow and accident hotspots.

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Geospatial and GIS terms may seem complicated at first, but with a little practice, they become second nature. Whether you’re working on a large-scale environmental project or just want to better understand how GPS works, knowing these key terms will make navigating the geospatial world much easier.

Looking for a way to dive deeper into geospatial data and make it work for your projects? Birdi’s tools can help you visualize, process, and analyze your geospatial data with ease. Give it a try and see the difference it can make!

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.