How frequently are TAMDAR measurements taken?
TAMDAR observations are based on pressure, rather than time, intervals during the ascent and descent phases. Time defaults are provided for portions of the flight when the aircraft is not significantly ascending or descending. All intervals and defaults are remotely adjustable from the data center. When operating under typical high-resolution settings, ascent and descent observations are made at 10 hPa (300 feet) pressure intervals up to 200 hPa (6000 feet) above ground level. Observations more than 200 hPa (6000 feet) above ground level are made at 25 hPa intervals. If an observation has not been made below 20,000 feet (465 hPa) for three minutes, then an observation is triggered by time default; if an observation has not been made above 20,000 feet (465 hPa) for seven minutes, then an observation is triggered by time default.
