Overhead 1090 Explains · Episode 2
What does an ADS-B receiver hear?
Updated October 2026
A home ADS-B station fits in your hand. Here is what each part does, and what it actually hears.
What's said in the video
Last time: every plane is talking. So what does it take to actually listen? That little box is the whole station. An antenna, a cheap USB radio, and a tiny computer. Every second it catches hundreds of messages, each plane's own address, call sign, altitude and position, and turns them into dots on a map. Live, from your own window.
The three parts
- An antenna tuned for 1090 MHz. A simple one indoors works; a proper one high up works much better.
- A USB software-defined radio, usually an RTL-SDR dongle, which turns the radio signal into data a computer can read.
- A small computer, typically a Raspberry Pi, running a decoder such as dump1090-fa (part of PiAware) or readsb.
What it hears
Every second the decoder can pick up hundreds of short messages. Each carries one aircraft's 24-bit address plus some of its details: call sign, altitude, position, speed, track, climb rate, and its four-digit squawk code. The decoder stitches those messages into one live picture of every plane in range and publishes it on your home network.
Seeing it
The decoder's own web page shows a map in a browser. Overhead 1090 reads the same feed and turns it into a native app on iPhone, iPad and Apple TV, with a logbook of every flight and alerts for unusual traffic. The PiAware guide shows how to connect it. Nothing leaves your network.
The series
- Ep. 1: What is ADS-B?
- Ep. 2: What does an ADS-B receiver hear?
- Ep. 3: How far can an ADS-B receiver hear?
See every plane over your house on iPhone, iPad and Apple TV: Overhead 1090 on the App Store, one purchase, no subscription.