Government Regulation Notes

Introduction

Because of the incursion of a Chinese balloon and the subsequent shooting down of three other balloons in Feb 2023, The FAA is reviewing their current regulations.  These new regulations may require the use of a radar reflector or electronics to locate the balloon. Clearly the current regulation of allowing a 4 lb suspended load will need to be modified.  We ballooners are committed to not causing danger to anyone.  An airplane flying at 500 mph hitting a 4 lb load would be devastating.

Steve G8KHW / AJ4XE <steve@randomaerospace.com>

To:

picoballoon@groups.io

Sun, Feb 12 at 3:21 PM

I think HF pico balloon flights might be reasonably visible to RADAR due to re-radiation from the antenna wires - acting like RADAR chaff.  Digging around in online papers (there are several on the RCS of long wires) I found this graph:

Where sigma is RCS, lambda is wavelength and l is the length of the wire.

The angle of incidence seems to have a significant effect - but worst case (broadside) the way I read this graph is you can expect the RCS to be approximately equal to the length of the wire - so maybe 10 square meters for a 10m long wire. Maybe I'm reading it wrong or extrapolating too far.

Steve G8KHW

On 12/02/2023 19:53, Bill Brown wrote:

Steve and all,

  Also note that NOAA READY HYSPLIT has been using our pico balloon flight tracks to validate their wind models.  So our amateur radio flights can be considered meteorological research flights as well.  At least one branch of the government knows of our flights but not sure if the military NORAD folks have any idea.  I doubt that the clear plastic balloons can be observed on radar...maybe more so for the aluminized balloons.

- Bill WB8ELK