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Category: Geographic Information Science

The Hungarian Parliamentary Building sits on the banks of the Danube. The GeoTIFF locates the building about 150 meters to the northeast of its true location.

The Secret Life of GeoTIFFs

Posted by: Carissa Pastuch

This is a guest post by Rachel Trent, Digital Collections and Automation Coordinator in the Geography and Map Division. The image below is of a TIFF file, but not just any TIFF. Hidden inside are coordinates that bind the image to a specific place on Earth. For every pixel in the image, an estimated latitude …

Screenshot of View from Above web map with clusters of maps shown on basemap of US.

New Interactive Map Showcases the Panoramic Maps Collection

Posted by: Tim St. Onge

The Panoramic Maps Collection, one of our most popular collections, features more than a thousand beautifully illustrated “bird’s-eye-view” maps of towns and cities across the United States, Canada, and even some internationally. To celebrate this collection, we are excited to launch View from Above: Exploring the Panoramic Map Collection, an interactive map that makes browsing …

Image with GIS Day logo

GIS Day 2022: Exploring Humanitarian GIS

Posted by: Meagan Snow

Happy GIS Day from the Library of Congress!   Today the Library celebrates GIS Day with a virtual event exploring the role of GIS in addressing humanitarian disasters. Today’s event aims to highlight the role that geospatial data and GIS technologies can play in creating positive change in the face of global humanitarian challenges. Geography …

Map of Washington DC in various colors indicating the grade of the streets.

Visualizing DC’s Municipal Infrastructure,1890 to 2022

Posted by: Meagan Snow

Maps can tell us all kinds of things about how others have viewed and shaped the world – from the borders of ancient empires to the layout of your neighborhood street grid. Today, spatial data commonly powers the maps and applications we use to access basic information about the places we inhabit: opening an app …

1853 Pilot Chart showing wind speeds

From Telegrams to Weather Apps: A Brief History of Wind Mapping

Posted by: Meagan Snow

Today it’s easy to check the weather without even leaving the house: hourly predictions for rain, wind, temperature, and humidity are available to most of us through our phones at the touch of a button. Warnings for severe weather flash across our screens to help keep us safe – but how did we get here? …