Patent ID: 8305230

Claim:
An apparatus for initializing a wellbore survey tool, the apparatus comprising: a base portion; a first mounting portion mechanically coupled to the base portion, the first mounting portion adapted to be mechanically coupled to at least one directional reference system, the at least one directional reference system configured to provide data indicative of an orientation of the at least one directional reference system with respect to a reference direction; and a second mounting portion mechanically coupled to the base portion, the second mounting portion configured to be mechanically coupled to a wellbore survey tool such that the wellbore survey tool has a predetermined orientation with respect to the at least one directional reference system, wherein the at least one directional reference system comprises at least one signal receiver of a global positioning system (GPS), wherein the at least one signal receiver comprises a first antenna and a second antenna spaced apart from the first antenna and defining a line from the first antenna to the second antenna.