Galileo's GIOVE-B broadcasting new MBOC signal

GPS World, June, 2008

Following its April 27 launch, GIOVE-B the second Galileo satellite, began transmitting navigation data on May 7, the European Space Agency (ESA) reported. GIOVE-B is now transmitting the Galileo L1 signal using a specific optimized wave-form, multiplexed binary offset carrier (MBOC), the signal that will be interoperable with the L1C signal to be used in future Block III GPS satellites, in accordance with the July 2007 agreement between the European Union and the United States. GIOVE-B signals were locked on-board by the satellite's passive hydrogen maser clock, the newest and most accurate clock in space.

Several facilities across Europe were involved in switching on and now monitoring the satellite's navigation payload, including the GIOVE-B Control Centre at Telespazio's facilities in Fucino, Italy; the Galileo Processing Centre at ESA's European Space Research and Technology Centre in the Netherlands; the ESA ground station at Redu, Belgium; and the Rutherford Appleton Laboratory Chilbolton Observatory in the United Kingdom.

Chilbolton's 25-meter antenna makes it possible to analyze the characteristics of GIOVE-B signals with great accuracy and verify that they conform to the Galileo system's design specification, according to the ESA. Each time the satellite is visible from Redu and Chilbolton, the large antennas at the facilities are activated and track the satellite. GIOVE-B orbits at an altitude of 23, 173 kilometers (14,399 miles), making a complete journey around the Earth in 14 hours and 3 minutes.

BOC Plural. According to a scientist involved with the Galileo signal design, GIOVE-B will transmit from time to time a Composite BOC (CBOC), the baseline signal for the Galileo Open Service (OS) at the common GPS/Galileo frequency at L1/E1, and from time to time a BOC(1,1) signal, for test purposes only.

The Galileo Interface Control Document (ICD) is available on the European GNSS Supervisory Authority website, although apparently the codes that GIOVE-B are transmitting are different from the ones in the Galileo ICD.