Andrew Yee[_1_]
March 5th 07, 04:41 AM
ESA News
http://www.esa.int
2 March 2007
GIOVE-A navigation signal available to users
The GIOVE-A Signal-in-Space Interface Control Document, the document that
gives the technical details of the signals transmitted by the GIOVE-A
satellite, has been released. This will allow receiver manufacturers and
research institutions to use a real signal for their research and
development.
Following the launch of GIOVE-A on 28 December 2005 from the Baikonur
Cosmodrome and the transmission of the first Galileo signals from medium
Earth orbit on 12 January 2006, ESA and Surrey Satellite Technology Limited
(SSTL United Kingdom) have completed the GIOVE-A in-orbit validation
activities. The GIOVE-A signal validation has been accomplished through a
network of 13 Galileo Experimental Sensor Stations (GESS), deployed world
wide, and a GIOVE Processing Centre which computes precise orbits and clock
timings for the GIOVE satellites, based on the measurements made by the GESS
and satellite laser ranging stations.
The GIOVE-A Signal-in-Space Interface Control Document (SIS-ICD) is the key
document that will allow any user to build a receiver able to track GIOVE-A
signals, interpret the navigation message and compute the distance between
the satellite and the receiver. Following the successfully in-orbit
validation mission, ESA has decided to release the SIS-ICD to the public to
allow receiver manufacturers and research centres to benefit from
experiments with a real Signal-in-Space for research and development
purposes.
This is possible since the nominal GIOVE-A navigation Signal-inSpace (SIS)
is fully representative of the future Galileo navigation signals, on all
three Galileo frequency bands, even though GIOVE-A uses specific spreading
codes that are different from the nominal codes of the final Galileo
constellation to allow unambiguous identification of the spacecraft. These
codes are described in the GIOVE-A public document and with knowledge of
them the GIOVE-A signals can be used for code and carrier phase tracking in
precisely the same way the future Galileo signals will be used. All GIOVE-A
signal spectra are identical to the future Galileo navigation SIS spectra.
The navigation data symbol rates are identical with the nominal Galileo data
rates for all public signals, and the same principles as in the final
Galileo navigation signal are used for message encoding. The navigation
message structure of GIOVE-A is different from the future Galileo navigation
signal, but the low level elements of the message differ only in minor
details. The content of the GIOVE-A navigation message is complete with all
ingredients such as, for example, ephemeris and clock correction, that are
needed for pseudo-range calculation and further positioning processing, thus
leading to a full set of navigation signals.
The time for simulation is over, so the ESA Galileo project team is putting
at the disposal of the user community the information needed to support the
validation of demanding Galileo user applications with a real satellite.
The GIOVE-A Signal-in-Space ICD is available at the GIOVE web site:
http://www.giove.esa.int/
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEM4EDN0LYE_index_1.html ]
http://www.esa.int
2 March 2007
GIOVE-A navigation signal available to users
The GIOVE-A Signal-in-Space Interface Control Document, the document that
gives the technical details of the signals transmitted by the GIOVE-A
satellite, has been released. This will allow receiver manufacturers and
research institutions to use a real signal for their research and
development.
Following the launch of GIOVE-A on 28 December 2005 from the Baikonur
Cosmodrome and the transmission of the first Galileo signals from medium
Earth orbit on 12 January 2006, ESA and Surrey Satellite Technology Limited
(SSTL United Kingdom) have completed the GIOVE-A in-orbit validation
activities. The GIOVE-A signal validation has been accomplished through a
network of 13 Galileo Experimental Sensor Stations (GESS), deployed world
wide, and a GIOVE Processing Centre which computes precise orbits and clock
timings for the GIOVE satellites, based on the measurements made by the GESS
and satellite laser ranging stations.
The GIOVE-A Signal-in-Space Interface Control Document (SIS-ICD) is the key
document that will allow any user to build a receiver able to track GIOVE-A
signals, interpret the navigation message and compute the distance between
the satellite and the receiver. Following the successfully in-orbit
validation mission, ESA has decided to release the SIS-ICD to the public to
allow receiver manufacturers and research centres to benefit from
experiments with a real Signal-in-Space for research and development
purposes.
This is possible since the nominal GIOVE-A navigation Signal-inSpace (SIS)
is fully representative of the future Galileo navigation signals, on all
three Galileo frequency bands, even though GIOVE-A uses specific spreading
codes that are different from the nominal codes of the final Galileo
constellation to allow unambiguous identification of the spacecraft. These
codes are described in the GIOVE-A public document and with knowledge of
them the GIOVE-A signals can be used for code and carrier phase tracking in
precisely the same way the future Galileo signals will be used. All GIOVE-A
signal spectra are identical to the future Galileo navigation SIS spectra.
The navigation data symbol rates are identical with the nominal Galileo data
rates for all public signals, and the same principles as in the final
Galileo navigation signal are used for message encoding. The navigation
message structure of GIOVE-A is different from the future Galileo navigation
signal, but the low level elements of the message differ only in minor
details. The content of the GIOVE-A navigation message is complete with all
ingredients such as, for example, ephemeris and clock correction, that are
needed for pseudo-range calculation and further positioning processing, thus
leading to a full set of navigation signals.
The time for simulation is over, so the ESA Galileo project team is putting
at the disposal of the user community the information needed to support the
validation of demanding Galileo user applications with a real satellite.
The GIOVE-A Signal-in-Space ICD is available at the GIOVE web site:
http://www.giove.esa.int/
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEM4EDN0LYE_index_1.html ]