--- title: Passive Radar Explained | daily.dev description: Passive radar works by listening to existing broadcast signals (like FM radio stations) rather than emitting its own transmissions, avoiding the risk of... canonical: https://daily.dev/posts/passive-radar-explained-15lrpcg6v twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Passive Radar Explained | daily.dev og:description: Passive radar works by listening to existing broadcast signals (like FM radio stations) rather than emitting its own transmissions, avoiding the risk of... og:url: https://daily.dev/posts/passive-radar-explained-15lrpcg6v og:image: https://api.daily.dev/og/posts/15lRPcG6v.png og:image:alt: Passive Radar Explained og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Passive Radar Explained **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 0 upvotes · 0 comments ## Summary Passive radar works by listening to existing broadcast signals (like FM radio stations) rather than emitting its own transmissions, avoiding the risk of revealing the antenna's location to radar-homing missiles. Using two effects — signal delay and Doppler frequency shift — a receiver can detect targets by comparing the direct broadcast signal with its reflection off the target. Unlike active radar, which produces circular position rings, passive radar yields ellipses, requiring signals from multiple stations to triangulate a target's position. A simple SDR receiver is sufficient to build one, and even satellites can serve as exciters. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [How Passive Radar Works](https://daily.dev/posts/how-passive-radar-works-t79kzlw35) · Hacker News · 0 upvotes · 0 comments - [Using A Scientific Satellite For Passive Radar](https://daily.dev/posts/using-a-scientific-satellite-for-passive-radar-aexkfgsec) · Hackaday · 0 upvotes · 0 comments - [Harmonic Radar Finds Hidden Electronics](https://daily.dev/posts/harmonic-radar-finds-hidden-electronics-wtpyaw1ca) · Hackaday · 0 upvotes · 0 comments --- Tags: [#signal-processing](https://daily.dev/tags/signal-processing) [View this post on daily.dev](https://daily.dev/posts/passive-radar-explained-15lrpcg6v) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Passive Radar Explained","url":"https://daily.dev/posts/passive-radar-explained-15lrpcg6v","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/passive-radar-explained-15lrpcg6v"},"datePublished":"2026-04-12T08:21:51.129Z","dateModified":"2026-04-12T08:22:08.562Z","description":"Passive radar works by listening to existing broadcast signals (like FM radio stations) rather than emitting its own transmissions, avoiding the risk of...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/4bd9278c311fe3de5f117b84b76994e0?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/4bd9278c311fe3de5f117b84b76994e0?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hackaday","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hackaday","logo":"https://media.daily.dev/image/upload/s--JhDfhy70--/f_auto,q_auto/v1767541814/logos/hackaday","url":"https://daily.dev/sources/hackaday"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/passive-radar-explained-15lrpcg6v","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"signal-processing","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hackaday","item":"https://daily.dev/sources/hackaday"},{"@type":"ListItem","position":3,"name":"Passive Radar Explained"}]} ```