Radio Inversion - A Refractivity from Radios (RFR) Application to Retrieve Continuous Vertical Refractivity Soundings in the Lower Atmosphere

Recently, under US Navy support, techniques have been developed to generate high resolution, continuous profiles of refractivity in the planetary boundary layer using radio frequency (RF) signals of opportunity. The technique is often referred to as Refractivity from Radios (RFR).  The software application employed for the results presented in this presentation is called Radio Inversion.  Using low cost passive receiver equipment, measurements of digital TV (DTV), radar, and Automatic Identification System (AIS) signals are used to generate one or multiple continuous vertical refractivity profiles in the vicinity of a receiver.  These profiles provide information about the vertical temperature and humidity profiles which are combined to define the vertical refractivity profile.  They are a natural comlement to other sounding techniques including radiosonde data and satellite occultation techniques.  RFR provides a combination of fast temporal updates and higher vertical resolution within the boundary layer that are not available in other sounding techniques.  It is expected that these profiles may provide a very useful source of data for use in high resolution forecast models.  Field data and results are presented, comparing retrieved profiles to radiosonde profiles taken at the same time.  And example profile of a weaker boundary layer is provided here, showing RFR results tracking real-time radiosonde results identifying the top of the planetary boundary layer.  Additional results will be presented, showing a variety of strengths and depths of the boundary layer.