2.1 Mission Elements

The main mission elements are:

• The VSOG, based at ISAS and NAO, which is responsible for the operation of the HALCA satellite.

• The ground tracking stations (GTSs), located at Usuda (operated by ISAS), Green Bank (GBTS, operated by NRAO), and Goldstone, Tidbinbilla, Madrid (DSN GTS, all three operated by the DSN). The interface for the DSN GTSs is the JPL DOTS team.

• The ground radio telescopes (GRTs), located around the world.

• The navigation groups, located at ISAS and JPL. The interface for the JPL Multimission navigation (MMNAV) group is the JPL DOTS team, although the ISAS and JPL navigation groups will bi-laterally exchange various data products during normal operations.

• The correlators, located at Mitaka, Socorro, Penticton, and (from late 1998) Dwingeloo. Near real-time fringe detectors will also be located at Usuda, Sagamihara and Green Bank.

• The Principal Investigators (PI). This group will not be considered in detail in this document - a separate document specifically for PIs is in preparation by the VSOG.