EDUCATIONAL Mercator to UTM: The Grid That Quietly Runs the World A 16th century sailor's trick for drawing straight compass lines eventually became the metre-precise grid modern GPS relies on. 31 May 2021•4 min read• TITrishunya India Share: WhatsApp Copy Link Previous The Arc/Node Model: How GIS Knows What Connects to What Next What is GIS? A Fun, Simple Guide to Mapping Data Back to all articles ×