Receiving & Tracking Weather Balloons (RadioSondes)

High Altitude Balloons have been used extensively by meteorological organizations around the world as weather balloons for purposes of obtaining measurements of key environmental variables i.e. wind speeds, temperature, humidity, pressure, etc. This data is used to model weather conditions and provide weather predictions. Meteorological organizations tend to launch such weather balloons at-least once a day from various locations across their countries for purposes of data collection. Here’s in Melbourne the BoM or Bureau of Meteorology (Australia) launches weather balloons twice a day, every day. Each of these weather balloons includes a radiosonde, in the case of Bureau of Meteorology (Australia) it happens to be a Vaisala RS41 radionsonde.

Radiosondes are battery-powered telemetry instrument packages that are carried into the atmosphere typically by a weather balloon primarily used for purposes of measuring altitude, pressure, temperature, relative humidity, wind (both speed and direction), and cosmic ray readings at high altitudes. One of the most popular type of radiosondes is the Vaisala RS41. Check out the insides of a Vaisala RS41 in the following video.

A look inside the Vaisala RS41 radiosonde

If you intend to track and retrieve RS41 Radiosondes launched twice a day by Bureau of Meteorology (BoM, Australia) you’ll need to setup your RTLSDR and your Raspberry Pi with the following software –

  1. Auto_rx –
  2. Chasemapper –

Both Auto_Rx and Chasemapper are designed to work with the RTLSDR on a Raspberry Pi. Prior knowledge of Unix or hands on experience with Linux will definitely help if you are wanting to build your own HAB tracking setup with Auto_Rx and Chasemapper on the Raspberry Pi with the RTLSDR. Chasing weather balloons and retrieving the Radiosondes can be an exhilarating experience.

The meteorological organizations that launch these radiosondes is most cases do not attempt to retrieve them post the launch. However, in some cases they do offer a cash incentive for their more expensive payloads (The BoM Australia Ozone Sonde payload is launched a lot less frequently i.e. once a week). After you’ve caught one of these, you can’t but want to keep chasing them again and again and again!!!!!

We recommend using different Raspberry Pi’s for tracking BoM Radiosondes v/s re-programmed radiosondes used on the EMDRC HAB payload. This stems from potential issues running Auto_Rx, and horusdemodlib since out of the box they are both configured to run on the same software ports.

If you run into any issues drop us a note at trevor at hack2 dot live and we’ll do our best to point you in the right direction.