I can check ‘Latitude’ and ‘Longitude’ of imported Google Earth Terrain model by geolocation information dialog. It shows X-Y-Z axis origin (0, 0, 0), but how can I check the ‘Altitude’ of this point ?
Do I have to export KMZ file and check the kml file contents?
The Lat. Long. coordinates of imported Google Earth terrain coincide with the SketchUp Origin (0, 0, 0)
AFAIK there is no real-world elevation data brought into the model.
In my sample KMZ export, I see the doc.kml referenced elevation “relative to ground” like this:
/<Model><altitudeMode>relativeToGround</altitudeMode><Location><latitude>42.544315</latitude><longitude>-88.406918</longitude><altitude>0</
Of course, rudimentary elevation data is displayed in Google Earth.
And here’s another app that may be of interest: Google Maps Find Altitude
Thank you for quick reply and useful LINK.
I understand that model origin located relatively to Google Earth’s Ground identified by Lat. & Long.
When I check my sample KMZ export, there was ‘altitude’ value in the ‘LookAt’ paragraph, but it was not the model position.
Thank you again 
To get the elevation [altitude] of a fixed point in Google Earth first make a short path - say 1m long, drawn at some memorable Lat/Long on the area in question: using Add > Path… - set its Altitude == Clamped to Ground
Set the Measurement units == say meters…
Then use Edit > Show Elevation Profile
A graphical representation of the path appears along the bottom of the view.
The start of the path is given in the units - say meters…
That is the elevation [altitude] of that first Lat/Long point.
Since the whole mesh is setup relatively, you can then use that particular elevation to move the mesh upwards, or more sensibly setup a Z ‘datum’ from that when it is actually == 0…
[See this tool, which might help once you have the ‘datum’ resolved…
SketchUp Plugins | PluginStore | SketchUcation ]
Many thanks TIG!!
I could check altitude with GoogleEarth Path and its profile (m unit).
And also I appreciate your extention, Coords-Tag from Datum !!
Its very usefull for modeling site that numerically surbeyed, too !!