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.
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.