CZMLGroundStation.md

 This page describes the content of a CZML document. Please read [How to get started](How to get started) for an explanation of how a CZML document is put together.
 
-**Extends** : [CZMLPrimaryObject](CZMLPrimaryObject)
+**Implements** : [CZMLPrimaryObject](CZMLPrimaryObject)
 
 **Example** :
 ```json