Use density altitude or station pressure correctly

FreeDOPE can describe the atmosphere from density altitude or from component measurements. The important part is knowing which source is authoritative and what the pressure number represents.

Density altitude is a compact description of current air density. When present, FreeDOPE treats it as the atmosphere authority. Station pressure is the actual pressure at the observation elevation and can define the atmosphere when density altitude is not supplied. An altimeter setting is adjusted for aviation use and is not interchangeable with local station pressure. Temperature and humidity still belong to the recorded environmental snapshot and help explain the source and conditions used.

Example. If a trusted range meter reports 4,200 ft density altitude, use that as the authority. If you instead build the atmosphere from pressure, enter actual station pressure—not a weather report's sea-level or altimeter value.

If You have both density altitude and a pressure value.: Decide which measurement you trust as the authority. In the current solver, supplied density altitude takes precedence; keep the source and timestamp clear so another person can understand the choice.

Avoid accidental double correction. When density altitude is authoritative, do not manually alter unrelated profile inputs to recreate the same atmospheric effect. Change the atmosphere at its source and review a fresh solution.

Stop when pressure semantics are unknown. Do not enter a pressure number merely because it is available. Determine whether it is station, altimeter, or sea-level pressure first.