Phase and phase‐difference ionospheric radio tomography

Abstract Variants of ray ionospheric radiotomography (RT) are considered: the phase RT based on measuring the absolute phase or the total electron content and the phase‐difference RT based on measuring the phase‐difference RT based on measuring the phase difference or Doppler frequency. The phase technique is shown to give poor results with typical errors in determining the absolute phase. The previously developed technique of the phase‐difference RT is presented.©1994 John Wiley & Sons Inc