Maximum unambiguous range

{
  "id": "MLC-T-MET-001648",
  "term": "Maximum unambiguous range",
  "field": "Meteorology and atmospheric science",
  "definitions": [
    "The greatest distance from a radar at which a target's echo can be received and correctly assigned to its true range without being confused with echoes from previous radar pulses. This range is inversely proportional to the pulse repetition frequency of the radar system. Exceeding this range leads to range folding or second-trip echoes.",
    "The range from the radar at which an echo can be known unquestionably as being at that range. As the radar sends out a pulse of energy, the pulse hits a target and part of the energy bounces back to the radar, but part of the energy may continue to travel away from the radar. The distance to the target is computed by knowing the time that has elapsed since the pulse was emitted. Then a second pulse of energy is transmitted. If some of the energy from the first pulse strikes a target at a far range and returns to the radar when radiation from the second pulse arrives, the RDA misinterprets the returned first pulse as arriving from a target near the returned second pulse. The maximum unambiguous range is related to the amount of time that elapses between successive pulses of emitted energy."
  ],
  "see_also": [
    "second-trip echo",
    "range aliasing"
  ],
  "references": [
    "NWS Glossary"
  ],
  "url": "https://mlchart.com/terminology/meteorology/maximum-unambiguous-range/"
}