Short on time before UPSC Prelims and struggling with tricky concepts? The exam increasingly tests your conceptual clarity and ability to apply core ideas, especially in the most dynamic subjects: Science, Economy, and Environment (SEE). UPSC Essentials’ new initiative, UPSC Prelims ‘SEE’ Snapshot, brings you, every Wednesday , a quick, exam-focused revision of key concepts. In each article, we pick three important current themes from Science, Economy, and Environment and decode them strictly through the Prelims lens—focusing on concepts and clarity. SCIENCE GPS interference   Core Concept:  — Both ships and aircraft depend on global navigation satellite systems (GNSS) for position, navigation, and timing (PNT) information. Of these, the American Global Positioning System (GPS) is the most popular GNSS, with the terms often used interchangeably.…