%0 Journal Article %1 Jales2008 %A Jales, P. %A Weiler, R. %A Underwood, C. %A Unwin, M. %D 2008 %J Proc. of the International Technical Meeting of the ION %K GPS, highSensitivity satnav %T First Spaceborne Demonstration of Galileo Signals for GNSS Reflectometry %X Surrey Space Centre and Surrey Satellite Technology Ltd (SSTL) have pioneered the use and construction of space GNSS receivers for orbit determination and time transfer for small satellites. Spaceborne GNSS receivers also have an interesting application in remote sensing. In GNSSReflectometry the signals are detected after they have reflected from the Earth to determine properties of the surface, for example ocean wave conditions. The opportunity to use GPS signals for remote sensing opens up microwave remote sensing to small, low cost instruments. With the first Galileo-type signals now being broadcast from the GIOVE satellites, the potential of Galileo reflectometry can now be evaluated experimentally. The use of Galileo signals for reflectometry increases the number of reflections and hence the spatio-temporal coverage, however the use of both systems is non-trivial due to differences in signal structure. In 2003, SSTL launched an experimental receiver as a secondary payload on a Disaster Monitoring Constellation satellite, UK-DMC. This experimental receiver could be configured as a signal recorder, the intermediate frequency (IF) signal is stored for 20 seconds and transmitted to the ground for post-processing. Using this equipment, reflections of GPS signals were detected from all types of surfaces on the Earth. The UK-DMC receiver is optimised for GPS L1, but it fortunately is also capable of receiving some of the energy from the greater bandwidth, Galileo L1 signal. The direct signal from GIOVE-A was acquired and tracked despite the insufficient bandwidth of the available RF frontend. For the first time in orbit, ocean reflected Galileo (GIOVE-A) signals have been detected. These are presented along with the signal processing techniques. The Galileo L1 signal is comprised of several components, which can be combined in the receiver to maximise signal-to-noise ratio. A problem particular to space-based GNSS reflectometry is that due to the geometry of the satellite motion, the signal loses coherency for integrations longer than around 1ms. The shortest Galileo L1 code is 4ms, therefore the new, longer, spreading codes require special receiver algorithms to use the signals for this unintended application. To demonstrate the potential of GNSS reflectometry some results are presented from signals reflected off sea ice.

@article{Jales2008, abstract = {Surrey Space Centre and Surrey Satellite Technology Ltd (SSTL) have pioneered the use and construction of space GNSS receivers for orbit determination and time transfer for small satellites. Spaceborne GNSS receivers also have an interesting application in remote sensing. In GNSSReflectometry the signals are detected after they have reflected from the Earth to determine properties of the surface, for example ocean wave conditions. The opportunity to use GPS signals for remote sensing opens up microwave remote sensing to small, low cost instruments. With the first Galileo-type signals now being broadcast from the GIOVE satellites, the potential of Galileo reflectometry can now be evaluated experimentally. The use of Galileo signals for reflectometry increases the number of reflections and hence the spatio-temporal coverage, however the use of both systems is non-trivial due to differences in signal structure. In 2003, SSTL launched an experimental receiver as a secondary payload on a Disaster Monitoring Constellation satellite, UK-DMC. This experimental receiver could be configured as a signal recorder, the intermediate frequency (IF) signal is stored for 20 seconds and transmitted to the ground for post-processing. Using this equipment, reflections of GPS signals were detected from all types of surfaces on the Earth. The UK-DMC receiver is optimised for GPS L1, but it fortunately is also capable of receiving some of the energy from the greater bandwidth, Galileo L1 signal. The direct signal from GIOVE-A was acquired and tracked despite the insufficient bandwidth of the available RF frontend. For the first time in orbit, ocean reflected Galileo (GIOVE-A) signals have been detected. These are presented along with the signal processing techniques. The Galileo L1 signal is comprised of several components, which can be combined in the receiver to maximise signal-to-noise ratio. A problem particular to space-based GNSS reflectometry is that due to the geometry of the satellite motion, the signal loses coherency for integrations longer than around 1ms. The shortest Galileo L1 code is 4ms, therefore the new, longer, spreading codes require special receiver algorithms to use the signals for this unintended application. To demonstrate the potential of GNSS reflectometry some results are presented from signals reflected off sea ice.}, added-at = {2011-05-30T10:41:10.000+0200}, author = {Jales, P. and Weiler, R. and Underwood, C. and Unwin, M.}, biburl = {https://www.bibsonomy.org/bibtex/2da98d5d308480d2903d6260e7d5093b7/bmuth}, groups = {private}, interhash = {f91f8ac7fb0043ab44b3c5ac05c53935}, intrahash = {da98d5d308480d2903d6260e7d5093b7}, journal = {Proc. of the International Technical Meeting of the ION}, keywords = {GPS, highSensitivity satnav}, month = {September}, owner = {admin}, timestamp = {2014-08-11T22:37:44.000+0200}, title = {{First Spaceborne Demonstration of Galileo Signals for GNSS Reflectometry}}, username = {bmuth}, year = 2008 }