This paper addresses the Test User Receivers
(TUR) of the Galileo Satellite Navigation System.
The paper explains the concept of TURs highlighting the
difference between TUR and a commercial receiver. An
outline of the high-level requirements for the TUR is
provided. Functional and performance requirements are
presented. The interfaces between the TUR and the Galileo
System are summarized, in particular the signals in space of
the Galileo System. The key differences between Galileo and
GPS receivers are identified, explained, and discussed
