Why Are Great Circles the Shortest Flight Path?
Airplanes travel along the true shortest route in a 3-dimensional space. This curved route is called a geodesic or great circle route.
Maps & Cartography
Where is the Central Meridian?
The central meridian is the center line of longitude for projection systems. Projected coordinate systems often use it as a reference point for a x-origin.
How to Track the Spread of Viruses Using GIS
Everyday, communities are at risk of transmissible diseases and growing pandemics like COVID-19. We use GIS to track the spread of viruses in real-time maps.
![50 Map Projections Types: A Visual Reference Guide [BIG LIST]](https://gisgeography.com/wp-content/uploads/2018/07/fuller-768x454.png)
50 Map Projections Types: A Visual Reference Guide [BIG LIST]
If you’re in need of a visual reference guide to map projection types, this goldmine of the top 50 global map projections used by cartographers will help.
Ocean Currents Map: Visualize Our Oceans Movement
Our ocean’s movements push large amounts of water every day. But where? See this list of ocean currents map and visualize our oceans movement and dynamics.
Dot Distribution vs Graduated Symbols vs Proportional Symbol Maps
While graduated symbols and proportional symbols scale the size of the symbol based on value, dot distribution maps use dots to represent quantity.
3 Wildfire Maps: How to Track Real-Time Fires Around the World
When wildfires burn, satellites (MODIS and VIIRS) track forest fires and deliver warnings to emergency crews. It all goes into real-time active fire maps.
![Epic Web Maps – The Maps Hall of Fame [Best Maps]](https://gisgeography.com/wp-content/uploads/2016/04/Maps-Hall-of-Fame-3-768x439.png)
Epic Web Maps – The Maps Hall of Fame [Best Maps]
The ultimate list of best maps online. These display state-of-the-art web mapping technology such as live feeds, 3D views and cutting edge visualization.
Geodesy: The Mathematics of “Where”
Geodesy is the field of applied mathematics that studies Earth’s shape, orientation, positions and gravity for the past, present and future.
How to Show Map Scale with Scale Bar, Inset Map and Ratio Text
There are several ways to help readers understand map scale and distance. For example, cartographers use scale bars, locator maps, stated and ratio scale.