Return the current elevation of a given source.

Arguments:

Source source

The source of interest.

Example 1:

The following example displays the elevation of mars.

  print $elevation(mars)

An example of the resulting output would be:

  LOG: -27:08:40.4445

Example 2:

The following example halts script execution until Mars rises above 40 degrees elevation.

 until $elevation(mars) > 30

Context:

The returned elevations have been corrected for precession and nutation, but not for atmospheric refraction or tilts in the telescope axes.