Tagged: vaisala

Reprogramming Vaisala RS-41 Radiosondes to Transmit APRS, RTTY, CW in the Ham or ISM Bands

Radiosondes are light weight sensor packages that are attached to weather balloons. They transmit live RF weather telemetry down to earth as they rise. With an RTL-SDR and appropriate antenna it can be possible to decode this telemetry. One related hobby that a few people enjoy is radiosonde chasing, which is tracking and collecting radiosondes once they have fallen back to the earth. Some people collect them as trophies, and others like to repurpose them. For example in this previous post we've seen how some radiosondes can be repurposed into L-band antennas for RTL-SDR's.

Another way to repurpose radiosondes has recently been submitted to us by regular contributor 'happysat' who wrote in and let us know that it is actually possible to reprogram the commonly used Vaisala RS-41 radiosondes into being able to transmit ham radio APRS, RTTY or CW mode signals in the ISM or ham bands. The initial hack was first performed by SQ5RWU, and then OM3BC who managed to create easier to use software that could reflash the radiosondes internal firmware via the serial port on the radiosonde. This hack could be useful for any ham requiring a cheap transmitter for their own high altitude balloon experiments.

Happysat ended up testing this software with some RS-41 radiosondes that he had, and managed to receive some generated signals with an RTL-SDR of his. Some photos that he's submitted are shown at the end of this post.

In addition to the above, happysat also wanted to mention his other radiosonde re-purposing project which was turning a DFM-06 and DFM-09 into a functional GPS unit that could be used for navigation when connected to a laptop, or to sync time on PCs.

Transmit APRS

Transmit APRS

xub
w7
PE2BZ's Modded RS41 with Solar Panels

PE2BZ's Modded RS41 with Solar Panels

RS41 Programmer

RS41 Programmer

Reprogramming Vaisala RS-41 Radiosondes to Transmit APRS, RTTY, CW in the Ham or ISM Bands

Radiosondes are light weight sensor packages that are attached to weather balloons. They transmit live RF weather telemetry down to earth as they rise. With an RTL-SDR and appropriate antenna it can be possible to decode this telemetry. One related hobby that a few people enjoy is radiosonde chasing, which is tracking and collecting radiosondes once they have fallen back to the earth. Some people collect them as trophies, and others like to repurpose them. For example in this previous post we've seen how some radiosondes can be repurposed into L-band antennas for RTL-SDR's.

Another way to repurpose radiosondes has recently been submitted to us by regular contributor 'happysat' who wrote in and let us know that it is actually possible to reprogram the commonly used Vaisala RS-41 radiosondes into being able to transmit ham radio APRS, RTTY or CW mode signals in the ISM or ham bands. The initial hack was first performed by SQ5RWU, and then OM3BC who managed to create easier to use software that could reflash the radiosondes internal firmware via the serial port on the radiosonde. This hack could be useful for any ham requiring a cheap transmitter for their own high altitude balloon experiments.

Happysat ended up testing this software with some RS-41 radiosondes that he had, and managed to receive some generated signals with an RTL-SDR of his. Some photos that he's submitted are shown at the end of this post.

In addition to the above, happysat also wanted to mention his other radiosonde re-purposing project which was turning a DFM-06 and DFM-09 into a functional GPS unit that could be used for navigation when connected to a laptop, or to sync time on PCs.

Transmit APRS

Transmit APRS

xub
w7
PE2BZ's Modded RS41 with Solar Panels

PE2BZ's Modded RS41 with Solar Panels

RS41 Programmer

RS41 Programmer

RTL-SDR Tutorial: Receiving Weather Balloon (Radiosonde) Data with RTL-SDR

Around the world meteorological weather balloons are launched twice daily, and continuously transit weather telemetry to a ground station using something called a radiosonde. The RTL-SDR software defined radio combined with a decoding program can be used to intercept this telemetry, and display it on your own computer. You will be able to see real time graphs and data of air temperature, humidity, pressure as well as the location and height of the balloon as it makes it's ascent.

Note that if you are in the USA, then this tutorial may not be applicable for you as different radiosondes are used. Instead have a look at this post which shows how to use the SkySonde software from NOAA. You can also try an alternative command line based decoder called RS available on GitHub.

This tutorial is also applicable to other software defined radios such as the Funcube dongle, Airspy, HackRF, BladeRF or even hardware radios with discriminator taps, but the RTL-SDR is the cheapest option that will work.

Examples

In this example YouTube user Superphish shows a radiosonde being received and decoded using a RTL-SDR, SDRSharp and SondeMonitor.

Weather Balloon (Radiosonde) tracking with RTL SDR (RTL2832), Sondemonitor and SDR Sharp

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