optional, multiple

waytime=absolute time in seconds since beginning of surfaceinterval

Inside <wayaltitude> an absolute altitude in metres above sealevel is put into brackets (given as a real number).

Each individual <wayaltitude> element must contain a waytime attribute which indicates the absolute time in seconds (given as a real number), when the altitude was reached.

<surfaceinterval>

—

<surfaceinterval>

(see also <surfaceinterval>)

<!-- an altitude of 500 metres above sea level is reached after 30 minutes -->
<wayaltitude waytime="1800.0">500.0</wayaltitude>
<!-- 15 minutes later an altitude of 700 metres is reached -->
<wayaltitude waytime="2700.0">700.0</wayaltitude>