Selection of different heights for software wind speed

Hello, may I ask if the software's query of wind speed at different heights, 10-100-250 meters above ground, is based on actual ground or sea level at 0 meters? Should we choose the corresponding altitude for the range of 500-30000 meters based on air pressure or the altitude of that point?

陆金铃
The layers marked as above ground are truly above the actual surface. Pressure levels are always measured relative to sea level, not the actual surface. The height calculation is only indicative in this case.

Ventusky
thank you very much