First off, what is the 2 meter band and why is it called that? In the United States, the FCC has allocated 144 MHz to 148 MHz for amateur radio use to those holding a Technician or higher license. Radio operators may use any mode whether it's AM, FM SSB, Data etc between 144.100 and 148.00 MHz. The use of only CW has been restricted from 144.000 to 144.100 MHz. Now why is it called the 2 meter band. This band is called 2 meter because a complete wavelength of 144 MHz is approximately 2 meters long.

Weather balloons and radiosondes are something that I've worked with early on in my electronics career. So when a co-worker told me about Sondehub, I was interested. Sondehub is like flight aware for weather balloons. It uses a SDR to receive a signal, in this case the weather balloons telemetry data, which is then sent over the internet to Sondehub where you can view the data on a map. Typically the National Weather Service stops tracking the balloon once it has popped and begins it's journey back to the ground. Using the SDR however, you can track the balloon until it reaches the ground. From there it's even possible to attempt to recover the radiosonde.