Altimeter Calibration Height

On Wed, 07 Mar 2007 21:37:53 -0800, TheSmokingGnu wrote:

The bottom of the landing gear? The height of the static port?

If you want to complicate your question ask about the other end of the
measurement, MSL.

From where do they measure MSL? Sea surface topography is constantly
changing. Do you measure from the tops of the waves? Bottoms? High tide?
Average tide? Average tide in the Pacific or average tide in the Atlantic?
How do you measure MSL in Panama? How do you get an average when currents,
air pressure variations, temperature and salinity variations are constantly
in flux? What about the melting and freezing of snow and glaciers? How
much time do you need to create this average?


--
Dallas

On Mar 9, 10:37 pm, Dallas wrote:
On Wed, 07 Mar 2007 21:37:53 -0800, TheSmokingGnu wrote:
The bottom of the landing gear? The height of the static port?

If you want to complicate your question ask about the other end of the
measurement, MSL.

From where do they measure MSL? Sea surface topography is constantly
changing. Do you measure from the tops of the waves? Bottoms? High tide?
Average tide? Average tide in the Pacific or average tide in the Atlantic?
How do you measure MSL in Panama? How do you get an average when currents,
air pressure variations, temperature and salinity variations are constantly
in flux? What about the melting and freezing of snow and glaciers? How
much time do you need to create this average?

--
Dallas

I know Wikipedia has something of a reputation, but they
put it in simple terms. Read http://en.wikipedia.org/wiki/Sea_level

They say MSL is 20' higher at the Atlantic end of Panama than at
the Pacific end. In the canal, of course, it will be much higher
between locks. That's not sea level anymore, it's manmade lake, about
80' MSL.

Dan

On Mar 11, 6:10 am, wrote:
On Mar 9, 10:37 pm, Dallas wrote:



On Wed, 07 Mar 2007 21:37:53 -0800, TheSmokingGnu wrote:
The bottom of the landing gear? The height of the static port?

If you want to complicate your question ask about the other end of the
measurement, MSL.

From where do they measure MSL? Sea surface topography is constantly
changing. Do you measure from the tops of the waves? Bottoms? High tide?
Average tide? Average tide in the Pacific or average tide in the Atlantic?
How do you measure MSL in Panama? How do you get an average when currents,
air pressure variations, temperature and salinity variations are constantly
in flux? What about the melting and freezing of snow and glaciers? How
much time do you need to create this average?

--
Dallas

I know Wikipedia has something of a reputation, but they
put it in simple terms. Readhttp://en.wikipedia.org/wiki/Sea_level

They say MSL is 20' higher at the Atlantic end of Panama than at
the Pacific end. In the canal, of course, it will be much higher
between locks. That's not sea level anymore, it's manmade lake, about
80' MSL.


Which is where QFE comes in :-)