Alidade

{
  "id": "MLC-T-MET-003431",
  "term": "Alidade",
  "field": "Meteorology and atmospheric science",
  "definition": "A sighting device used in conjunction with a plane table or other surveying instruments to measure angles and directions, particularly in older methods of meteorological observation or mapping. It consists of a rule with sighting vanes at each end, allowing an observer to draw lines on a map corresponding to the direction of observed features. While less common now, it was historically used for wind direction and cloud movement observations.",
  "url": "https://mlchart.com/terminology/meteorology/alidade/"
}