Radio horizon

{
  "id": "MLC-T-MET-008327",
  "term": "Radio horizon",
  "field": "Meteorology and atmospheric science",
  "definition": "The locus of points at which direct radio waves from a transmitter are tangential to the Earth's surface. Due to atmospheric refraction, which bends radio waves downward, the radio horizon extends beyond the geometric or optical horizon. For a standard atmosphere, the distance to the radio horizon is approximately 4/3 times the distance to the geometric horizon, a value that changes with atmospheric temperature and moisture profiles.",
  "see_also": [
    "effective earth radius",
    "scatter propagation"
  ],
  "url": "https://mlchart.com/terminology/meteorology/radio-horizon/"
}