Radiosonde for weather forecast || Payload for High Altitude Ballon

In this blog, I am going to talk about the radiosonde and what is this device and what is it used for.

Hello, we all know weather plays important role in our daily life. It is weather and climate which determines how we stay warm or cold today we can also know how will be the tomorrow's weather such as temperature humidity, will it rain tomorrow or not or what will be the humidity percentage. These questions are answered by weather department or from from weather station data.

Because of the technology it is possible to measure weather parameters. The Prime focus for today's article is about Radiosonde.

Radiosonde are the devices which are carried to the atmosphere using latex balloon to measure the temperature variation humidity wind speed etc. these data are kept in consideration for the prediction of weather these are basic parameters other different parameters are also taken under consideration for the better accuracy but manipulating more data is quite tedious job.

Every country uses this kind of devices, the Government of Nepal uses GRAW dfm09 radiosonde device for the measurement of weather parameters. The radiosonde with High altitude balloon or weather balloon is released from the Tribhuvan University (TU) ground at 5:45 AM everyday. The first flight took place on 1978, but it was discontinued that same year.[source]

Now, let's dig into GRAW dfm-09. It is an ultra low power device it has GPS device, humidity and temperature sensor. This operates on the range of 400 to 406 MHZ and works on FSK technique for modulation according to its datasheet. Two double A (AA) battery powers this device, these battery are not rechargeable.

For now let's see how we can detect and decode the device signals. RTL-SDR plays vital role for this purpose any SDR should work just fine. What is SDR let's not focus on that, it is a hardware device which receives RF signal comment down if you need a article regarding SDR devices

To detect and decode the radiosonde signal you gonna need any DSP software I am using SDR#. It is a great tool also sondemonitor to decode the signal as we can see in spectrum my device is transmitting at frequency about 402 Mhz.

Now we have to pipeline the output sound to mic. so, follow the steps and make sure you do it right (go through the embedded video)

Now open the sondemonitor and select the correct model if everything goes right you will a dialog box as seen in below picture with data that is being transmitted by the radiosonde device.