GPS - Pioneering Galileo Satellite Begins Third Year In Orbit

Author

Pioneering Galileo Satellite Begins Third Year In Orbit

Sam Wormley

2008-01-05, 3:33 pm

Pioneering Galileo Satellite Begins Third Year In Orbit
http://www.gpsdaily.com/reports/ Pi..._Orbit_999.html

by Staff Writers
Guildford, UK (SPX) Jan 03, 2008

The first satellite in Europe's Galileo satellite navigation
programme has achieved two years of highly successful in-orbit
operation. GIOVE-A secured a crucial Galileo frequency filing with
the International Telecommunications Union (ITU) and supported the
development and validation of technology crucial to the future of
Galileo.

The 660kg satellite was developed by SSTL for the European Space
Agency (ESA) to broadcast Galileo signals from space and claim the
frequencies filed with the ITU for Europe. SSTL designed, built and
tested the first Galileo satellite through a rapid (30 month)
development programme and within a 28 million Euro budget, and
launched the satellite on schedule on 28th December 2005.

Just 15 days later, at 17:25 GMT on the 12 January 2006, the first
Galileo signals were transmitted from the satellite. By March the
same year, ESA was able to confirm that it had brought the
Galileo-related frequency filings into use, three months ahead of the
official ITU deadline.

Since then, ESA has built up the GIOVE Mission Segment, comprising
Galileo Experimental Sensor Stations (GESS) distributed world-wide
and the GIOVE Processing Centre, to track the GIOVE A navigation
signals to generate orbit models and produce navigation messages.
This has enabled ESA to check both the instruments on-board the
satellite and the receivers on the ground and tests have confirmed
the success of the mission.

GIOVE-A has also assisted clock characterisation experiments that
enabled ESA to test the performance of the satellite's
state-of-the-art onboard rubidium atomic frequency clock. Initial
results demonstrated the clocks to be highly accurate, proving
technology that will be integral to all future Galileo satellites.

This small SSTL satellite is a pioneer - not only for its payload's
importance to Galileo but also for its Medium Earth Orbit (MEO)
location. Andy Bradford, SSTL's Engineering Director, recalls,
"European scientists possessed scant information about this new
operating environment. We knew very little about the effects of
radiation in this orbit and the design and protection of the
satellite was a significant engineering challenge. The knowledge and
experience gained first-hand from this successful mission is
significant for the development of future SSTL missions beyond LEO."

Operating at 23,258 km, GIOVE-A has proven reliable and gathered
important data about the MEO environment for use in future Galileo
missions.

On the 5th March ESA awarded a second contract to SSTL for initial
activities leading to the construction of a further spacecraft for
the Galileo satellite navigation system. Named GIOVE-A2, the new
satellite (estimated total value 25 to 30 million Euros) is based on
the Company's proven GIOVE-A technology. The intention is to provide
a follow-on mission to ensure signal continuity.

The next phase in Galileo has recently been confirmed with a
financing package of 3.4 billion Euros agreed by the European Union.
This requires a constellation of 30 satellites and an associated
worldwide network of ground stations to be deployed by 2013. SSTL
hopes to put the knowledge and technology developed through GIOVE-A
and GIOVE-A2 into practice in the next phase. On the 4th December
SSTL signed a Memorandum of Understanding (MOU) with German satellite
manufacturer, OHB Technology AG, signalling their willingness to bid
together for Galileo satellite contracts.

Tim Springer

2008-01-06, 7:33 am

The GIOVE-A mission has been very successfull and has led to some interesting results! It has been a major step in the Galileo
development cycle and one of the few very positive ones. A great success mainly thanks to SSTL.

In 2008 we may expect the long awaited launch of the GIOVE-B satellite as next step in the Galileo developments. This satellite
should more or less represent the final Galileo satellite design. If all goes well with the GIOVE-B there will not be too much use
for the GIOVE-A2 satellite. The GIOVE-A2 is (to my limited understanding) maily intended as back up in case something goes deadly
wrong with the GIOVE-B mission.

Nevertheless, I personally hope to see the GIOVE-A2 fly and work with its data.

Tim Springer
http://gnss.servolux.nl

"Sam Wormley" <swormley1@mchsi.com> schrieb im Newsbeitrag news:eQQfj.22648$Ux2.9425@attbi_s22...
> Pioneering Galileo Satellite Begins Third Year In Orbit
> http://www.gpsdaily.com/reports/ Pi..._Orbit_999.html
>
> by Staff Writers
> Guildford, UK (SPX) Jan 03, 2008
>
> The first satellite in Europe's Galileo satellite navigation
> programme has achieved two years of highly successful in-orbit
> operation. GIOVE-A secured a crucial Galileo frequency filing with
> the International Telecommunications Union (ITU) and supported the
> development and validation of technology crucial to the future of
> Galileo.
>
> The 660kg satellite was developed by SSTL for the European Space
> Agency (ESA) to broadcast Galileo signals from space and claim the
> frequencies filed with the ITU for Europe. SSTL designed, built and
> tested the first Galileo satellite through a rapid (30 month)
> development programme and within a 28 million Euro budget, and
> launched the satellite on schedule on 28th December 2005.
>
> Just 15 days later, at 17:25 GMT on the 12 January 2006, the first
> Galileo signals were transmitted from the satellite. By March the
> same year, ESA was able to confirm that it had brought the
> Galileo-related frequency filings into use, three months ahead of the
> official ITU deadline.
>
> Since then, ESA has built up the GIOVE Mission Segment, comprising
> Galileo Experimental Sensor Stations (GESS) distributed world-wide
> and the GIOVE Processing Centre, to track the GIOVE A navigation
> signals to generate orbit models and produce navigation messages.
> This has enabled ESA to check both the instruments on-board the
> satellite and the receivers on the ground and tests have confirmed
> the success of the mission.
>
> GIOVE-A has also assisted clock characterisation experiments that
> enabled ESA to test the performance of the satellite's
> state-of-the-art onboard rubidium atomic frequency clock. Initial
> results demonstrated the clocks to be highly accurate, proving
> technology that will be integral to all future Galileo satellites.
>
> This small SSTL satellite is a pioneer - not only for its payload's
> importance to Galileo but also for its Medium Earth Orbit (MEO)
> location. Andy Bradford, SSTL's Engineering Director, recalls,
> "European scientists possessed scant information about this new
> operating environment. We knew very little about the effects of
> radiation in this orbit and the design and protection of the
> satellite was a significant engineering challenge. The knowledge and
> experience gained first-hand from this successful mission is
> significant for the development of future SSTL missions beyond LEO."
>
> Operating at 23,258 km, GIOVE-A has proven reliable and gathered
> important data about the MEO environment for use in future Galileo
> missions.
>
> On the 5th March ESA awarded a second contract to SSTL for initial
> activities leading to the construction of a further spacecraft for
> the Galileo satellite navigation system. Named GIOVE-A2, the new
> satellite (estimated total value 25 to 30 million Euros) is based on
> the Company's proven GIOVE-A technology. The intention is to provide
> a follow-on mission to ensure signal continuity.
>
> The next phase in Galileo has recently been confirmed with a
> financing package of 3.4 billion Euros agreed by the European Union.
> This requires a constellation of 30 satellites and an associated
> worldwide network of ground stations to be deployed by 2013. SSTL
> hopes to put the knowledge and technology developed through GIOVE-A
> and GIOVE-A2 into practice in the next phase. On the 4th December
> SSTL signed a Memorandum of Understanding (MOU) with German satellite
> manufacturer, OHB Technology AG, signalling their willingness to bid
> together for Galileo satellite contracts.

pat_n_ed@yahoo.com

2008-01-07, 4:33 am

Richard Langley posted this on CANSPACE:

https://listserv.unb.ca/cgi-bin/wa?...pace&T=0&P=1187

"Date: Sun, 6 Jan 2008 17:25:10
Sender: Canadian Space Geodesy Forum
From: "Richard B. Langley"
Subject: GIOVE-B Launch Date

According to Russian sources, the launch of the second Galileo test
satellite, GIOVE-B, has been scheduled for 14 April 2008."

Wikipedia shows the same launch date:

http://en.wikipedia.org/wiki/GIOVE

"Launch has been delayed due to technical problems, and is now
scheduled for 14 April 2008 aboard a Soyuz-FG/Fregat rocket provided
by Starsem."

- -

2008-01-07, 10:33 pm

On Sat, 05 Jan 2008 19:24:58 GMT, Sam Wormley <swormley1@mchsi.com>
wrote:

>Pioneering Galileo Satellite Begins Third Year In Orbit
> http://www.gpsdaily.com/reports/ Pi..._Orbit_999.html
>
>by Staff Writers
>Guildford, UK (SPX) Jan 03, 2008
>
>

What frequencies / modes does this bird use?

John An American Amateur

Tim Springer

2008-01-07, 10:33 pm

For GIOVE-B the latest I have heard was June 2008.....

<pat_n_ed@yahoo.com> schrieb im Newsbeitrag news:1460f266-9a2f-4b48-a710- 57be87cc10c2@l6g2000
prm.googlegroups.com...
> Richard Langley posted this on CANSPACE:
>
> https://listserv.unb.ca/cgi-bin/wa?...pace&T=0&P=1187
>
> "Date: Sun, 6 Jan 2008 17:25:10
> Sender: Canadian Space Geodesy Forum
> From: "Richard B. Langley"
> Subject: GIOVE-B Launch Date
>
> According to Russian sources, the launch of the second Galileo test
> satellite, GIOVE-B, has been scheduled for 14 April 2008."
>
> Wikipedia shows the same launch date:
>
> http://en.wikipedia.org/wiki/GIOVE
>
> "Launch has been delayed due to technical problems, and is now
> scheduled for 14 April 2008 aboard a Soyuz-FG/Fregat rocket provided
> by Starsem."

Tim Springer

2008-01-15, 10:33 pm

"- -" <jwraynor@bellsouth.net> schrieb im Newsbeitrag news:i295o3dmeqkh8g3
0184t2majtseqv604ok@
4ax.com...
> On Sat, 05 Jan 2008 19:24:58 GMT, Sam Wormley <swormley1@mchsi.com>
> wrote:
>
>
> What frequencies / modes does this bird use?
>
> John An American Amateur

This signal structure and frequencies are similar to GPS but not identical.
Galileo, just like the future GPS satellites, will use three frequencies.
However, GIOVE-A (the bird in question) can transmit on all three
frequencies but only on two at a time. Both system use the CDMA technology
(Code Devision Multiple Access) compared to russian Glonass system which
uses the FDMA technology (Frequency Devision Multiple Access). There has
been a lot of discussion and work done on the so called "inter-operability"
of GPS and Galielo. Fortunately, these international discussions have been
successfull and thus GPS and Galileo will be fully interoperable. This eases
the life of the receiver manufacturers.

So to come back to your question.
GPS uses L1 and L2 which have a central frequency of 1575.42 and 1227.6 MHz
respectively. GPS will move to using three frequencies in the future, with
the central frequency of the third signal (L5) at 1176.45 MHz.

Galileo (and thus also GIOVE-A) transmits on:
- E1 with as central frequency 1575.420 MHz (same as GPS L1).
- E5 with as central frequency 1191.795 MHz (overlaps with future GPS L5
frequency)
- E6 with as central frequency 1278.750 MHz

The E5 signal has a relatively broad band and it actually contains two
signals, referred to as E5a and E5b with a central frequencies 1176.450 MHz
(GPS L5) and 1207.140 MHz.

To explain this I just made a page on my (still very incomplete GNSS web
site). So have a look at the page: http://gnss.servolux.nl/gnss_signals.html
Click on the picture to get a larger version of it so you can see the
frequency bands used (or planned to be used) by GPS and Galileo (let me know
if you liked it).

Not 100% sure but I think at the moment Giove-A is transmitting on E1 and
E6.

Cheers,
Tim
http://gnss.servolux.nl

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