Radiosonde Page




At the beginning of 2017 I discovered the world of radiosonde.

This page contains some works on this subject.



7 elements Yagi Uda antenna

An article (wrote in italian language) that describes how to build a Yagi Uda Antenna running on 403 MHz.

Here the direct link 403 MHz Yagi Uda Antenna



Sonde Archive

I've created a Database containing all the radiosondes received from my station.

It's also possible to perform tracking comparison and soon I 'll add atmospheric data.

Here the direct link Sonde Archive



RS41 tool

This kind of sonde implements an automatic power off procedure called "burst killer".

The status of this feature is directly reported by the RS41 sonde in its telemetry.

This simple tool can read a Rs41 telemetry file in order to provide an early indication on burst killer status.

The following picture shows an example of RS41 tool results



Here the direct link to download the tool RS41 tool Release 0.1 (280 Kbytes)


RS41 Tracker

RS41 Tracker is a software running on Windows that it’s able to decode telemetries generated by Vaisala RS41 radiosondes.

Used in conjunction with a FM radio receiver it allows operators to display radiosonde positions on a map and to control other meaningful parameters like temperature, wind speed/direction and burst killer related information.

All in real time.


Main features are:

* Directly decoding of GFSK signal received by the FM radio receiver (the use of a Software Defined Radio is recommended).

* Capability to connect and command SDRSharp software by mean of Net Remote Control plugin.

* Advanced frequencies scan, decode and restart: RS41 Tracker is able to look for RS41 radiosonde signal in a given list of frequencies, starting the radiosonde decoding when a valid signal is detected.

* Real time showing radiosonde position on map (online/offline mode are available)

* Draggable Map auto centered on radiosonde position

* Map type Dynamically selectable by user (OpenStreetMap, OpenTopoMap).

* Burst killer detailed information and launch time estimation.

* Integration with SondeHub network.

* Integration with APRS network: Rs41 tracker is able to connect to APRS-IS servers in order to provide information on locally received radiosonde, and to receive and show on map radiosonde information received from APRS users (bidirectional connection - Internet connection required)

* Radiosonde RAW data save

* Post processing of RS41 RAW data file

* Tracking information (elevation, bearing, slant range)

* Radiosonde track saved on kml and gpx file

* Ghost track shown on map (loading from kml file)

* Shortcut for google maps in browser

* Ozone sensor telemetries

* Estimation of PTU parameters

* Automatic software updates check (at startup and on demand)

* Precise pressure calculation for Rs41-SGP model

* Antenna Rotor Handler (Several protocol)

* RS41 Telemetry export in csv format

* GPS-IN interface. Software can use an external GPS (NMEA protocol) in order to update "home" position and telemetries in realtime

* Advanced audio signal monitor

* Detection of any auxiliary sensors connected to RS41 sonde

* Auxiliary sensors telemetry decoding and export (supported sensor:OIF411, COBALD, CFH, SKYDEW)

* Stüve Diagram (Preliminary)


The following picture shows how RS41 Tracker looks



Here the direct link to download the tool RS41 Tracker V02.4 BETA (2.94 Mbytes). See ChangeLog@31/03/2023

and here a link to download a zip file containing a RS41 RAW sample file RS41 RAW data file (zipped) (2.2 Mbytes)




RS41 tracker is provided free of charge but if you want you can support my software development activity by donating an Amazon gift card. Values start from 0,15 euro. (15 cent).

If possible, please directly use the amazon italian site (amazon account works worldwide) and choose delivery by mail: escursioni@altervista.org.

Here you can find the step by step procedure that can be used to donate a gift card using the Amazon italian site.


Feedback,suggestions and bugs reports are also welcome.