Thread: fdsnstationxml station creationDate element vs attribute

Hi

In fdsnstationxml 1.0, the Station has both a CreationDate element and a
TerminationDate element and via BaseNodeType a startDate and endDate
attribute.

The docs are a little unclear on what the difference is. I am guessing the
attribute is the "station epoch" and the elements are the first known epoch
start to the last know epoch end? Correct?

The only case this seems to me to be useful is the case of having some
station epochs but not all? If you have all station epochs then this is
redundant information, correct?

There is no corresponding items in channel even though it can have the
similar epoch concepts. I assume there is less interest in knowing
"overall" lifetime of a channel vs station?

Also, what is the distinction between alternateCode and historicalCode in
BaseNodeType? They seem more or less the same as far as I can tell.

thanks
Philip