Airplane flying height

[NHSARainer]

Hi,

A dumb question. Is the airplane height measured over sea level ?

Thanks

[Runway 31]

It is based on the QNH
QNH - The pressure set on the subscale of the altimeter so that the instrument indicates its height above sea level. The altimeter will read runway elevation when the aircraft is on the runway.

Normally based on a pressure of 1013Mb and above the transition level the altitude is shown as Flight Level and below the transition level in feet.

You can set both in File/Preferences/Radarbox but best just leaving it as ot comes

Alan

[NHSARainer]

Hi Alan,

Thank you. I was thinking about my coverage area and as ADS-B is line of sight reception as I read somewhere and making then the calculation a plane flying at a height of 12000 meter minus my 2000m height over sea level I theoretically can receive its transmission up to 412 km ... https://www.everythingrf.com/rf-calculators/line-of-sight-calculator

So I guess I am quite well as also I have to take into consideration my surrounding.

I have a high house (~9-10m high) to the South not more then 14meters from my antenna, as well as to the Southwest while looking north and East I have a good line of sight. Perhaps I go up to the roof and take a panorama picture :-)

Interesting stuff

regards Rainer