Mode Radiosonde

Radiosonde weather balloons: position, altitude and weather data.

Group	Weather & science
Default frequency	403 MHz
Default sample rate	8 Msps
In the mode list	Balloons, 403 MHz

Step-by-step: Tutorial-Radiosonde

What Radiosonde is

Radiosondes are small weather instruments carried by balloons, transmitting position and weather data near 400 to 406 MHz.

Frequencies and settings

Weather balloons, 400 – 406 MHz.

Setting	Value
Start frequency	403 MHz
Tuning range of the mode table	380 to 1700 MHz
Sample rate asked	8 Msps
Lowest working rate	2 Msps
Channel width	6 MHz

OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is Balloons, 403 MHz.

What OnAir shows

Balloon tracks, altitude and weather data.

The mode's own tab has these screens: Map, Table. The other tabs (Overview, Receiver, Scan, History) are described on the Main window page.

Tips and caveats

• Checked with generated signals and impairments; recordings of real signals welcome.
• Which radio: Usually yes for narrowband signals: an RTL-SDR tunes roughly 24 MHz to 1.7 GHz at up to about 2.4 Msps. Wide signals such as TV channels need a faster radio, and OnAir says next to the source what the selected radio can do.
• Try it without a radio: most modes include a built-in synthetic test signal, so you can open the screen and try the controls first.
• Receiving and the law: Receiving these signals is legal in most countries. OnAir is a receiver. See Legal.

Related pages

• All modes, Weather & science
• Supported radios, Troubleshooting, FAQ
• More in Weather & science: HRPT / AHRPT, NOAA Weather Radio SAME, Time signals, Ionospheric sounders, Radio astronomy