Relative take-off height and fusion height

Keywords: relative height, fusion height

The difference between the relative take-off altitude and the fusion altitude is that the altitude origin is different. The relative take-off altitude uses the take-off point of the aircraft as the origin, and the fusion altitude uses the standard atmospheric pressure (standard pressure sea level) as the origin.

Both altitudes use the barometric standard altitude conversion model (the MSL (Main Seal level) height at 15°C is 1013.25mBar, and the temperature drop rate per 1000m is -6.5°C), and the environment where the aircraft takes off is affected by temperature , Humidity, and even the influence of airplane fans, air pressure changes are not completely consistent with the standard model, so the absolute altitudes obtained from these two altitudes are unreliable.

The fusion height cannot be used as the altitude measurement. In addition, the height difference obtained by using two points relative to the take-off height generally has a larger error when the distance is relatively long. Another factor that affects the fusion altitude data is the difference in aircraft manufacturing. In the same physical location of two different aircraft, the fusion altitude may differ by tens of meters.

Note: This article is from Chinese and is translated by machine. If there is any error, please point it out and we will correct it in time