D-value
The quantity D describing the altitude of a point on a constant-pressure surface by its departure from “standard” altitude:
where Z is the actual altitude above mean sea level and Zp is the pressure altitude of the same point.
The quantity D describing the altitude of a point on a constant-pressure surface by its departure from “standard” altitude:
where Z is the actual altitude above mean sea level and Zp is the pressure altitude of the same point.