Permanent echo

{
  "id": "MLC-T-AVN-000718",
  "term": "Permanent echo",
  "field": "Aviation and air traffic control",
  "definition": "Radar signals reflected from fixed objects on the earth's surface; e.g., buildings, towers, terrain. Permanent echoes are distinguished from “ground clutter” by being definable locations rather than large areas. Under certain conditions they may be used to check radar alignment.",
  "references": [
    "FAA Pilot/Controller Glossary"
  ],
  "url": "https://mlchart.com/terminology/aviation/permanent-echo/"
}