Constant-pressure-pattern flight

{
  "id": "MLC-T-MET-004623",
  "term": "Constant-pressure-pattern flight",
  "field": "Meteorology and atmospheric science",
  "definition": "A flight technique in which an aircraft holds a constant pressure altimeter setting and altitude, so it follows an isobaric surface, while a radio altimeter gives the true height of that surface. The change in the difference between the two heights measures the slope of the pressure surface along the track, which is converted to the crosswind through the geostrophic wind relation. John Bellamy proposed the method in 1943.",
  "url": "https://mlchart.com/terminology/meteorology/constant-pressure-pattern-flight/"
}