Star tracking

A number of European organizations, including E.ON, are to launch the world’s first commercial satellite positioning system to rival the existing military controlled GPS and Glonass systems. PEi tracks the progress of the project and examines how it will help utilities in their day-to-day business.

Robin Rowshangohar, Assistant Editor

Stars in the sky have provided guidance to the world for centuries. People have long looked up for answers to questions hoping that an all-knowing aura will be able to provide some direction and security. In the past it was conventional star constellations that were looked to in the belief that they held mythical powers and supreme knowledge, but since technological advancements have allowed science to play a greater role in this fascination, the powers have moved out of mythology and into reality.

Today, satellites have become modern versions of star constellations, a development that Galileo possibly foresaw when he discovered the Milky Way. The Italian philosopher, astronomer and mathematician, who led the scientific revolution of the earth’s atmosphere famously once said: “Measure what is measurable and make measurable what is not so”, and it is this value that is at the heart of the world’s first commercial satellite positioning service.

Launch pad

At present the utility sector is served by two military controlled satellite networks, GPS and Glonass, which are controlled by the US and Russia respectively. After comprehensive market research was conducted investigating the viability of an EU-backed global satellite system it was concluded that a new commercially run system would need to be able to provide the service guarantees, security and integrity that would encourage greater use from sectors that use terrestrial measuring.

A document obtained from HiTec, the company responsible for the project’s market research, highlights: “The interviewees quoted that in particular integrity and security of the service are an issue. They stated that when using current GNSS (Global Navigation Satellite Systems) they sometimes receive incorrect signals, but are informed about this fact only later.”

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It was from this point that the so-called Galileo satellite navigation system was launched. When complete, the €3.2 billion ($4 billion) project between the European Union, the European Space Agency and the private sector, will be commercially run and designed to compete with the world’s existing two navigation networks.

To guarantee availability for critical applications Galileo will consist of 27 satellites and three active spares that in addition to the 13 satellites used for Glonass and the 28 used for GPS will mean extra security for utility users. The first of Galileo’s 30 satellites was launched in December 2005 when a 600 kg satellite named Giove-A was placed 23 222 km into orbit by a rocket from a cosmodrome in Kazakhstan. The project team aims to have eight satellites in operation by 2008 and all 30 should have been launched by 2010, though a source close to the project reveals that this objective is likely overrun by one or two years.

Galileo has already had an impact on its rival systems as both have responded to improve their service. The Russian operators are working to launch more satellites while the US Department of Defence removed Selective Availability from GPS in 2000 taking away what many had blamed as its single largest cause of error.

Signal harmony

As those behind the European system are working to harmonize the signals with the Glonass and GPS systems, there should be no fundamental problems preventing utility users from accessing any combination of satellites to improve availability, as long as the hardware and software is compatible. It is the commercially developed system, though, that will be the first to offer availability guarantees to users who will be informed within seconds of a failure of any satellite, a key strength for those in the energy industry.

Bastian Huck, a consultant at German company Allsat, the part of the project management team responsible for GNSS applications and receivers, says: “Galileo will be under civil control, also giving service guarantees. A better reliability and integrity of Galileo signals will probably increase the usage of satellite based receivers in safety related and crucial applications.”

Figure 1. Evolution of GNSS based surveying in comparison to terrestrial methods 2005-2020
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Two key drivers behind the development of Galileo applications are increased availability and security guarantees, but with the commercial sector taking a leading role, there will have to be sufficient demand to warrant the development of new services.

The project team is currently researching around 30 potential applications for the energy industry. Approximately 15 of these are in routine surveying, 11 in first time grid measurement, three in network expansion and modification and one in general maintenance.

Extra terrestrial

Market research shows that the biggest advantages the system will bring will be from “considerable cost and time savings”. It is estimated by the Galileo team that increased efficiency realised by using GNSS for surveying applications results in working time savings of between 30 and 70 per cent.

Research shows a future trend toward GNSS based surveying. GIGA project manager, Michael Stelz, who is also part of the E.ON Rhurgas team behind the Ascos mapping system selected for the project, says: “At the moment nearly 50 per cent of all surveying applications are done via GNSS. By 2020 this will be 90 per cent. The reason for the increased uptake will be availability.”

The benefits are not just confined to first time electricity grid construction. According to the team responsible for Galileo’s Integrated Georeference Applications (GIGA) electronic mapping systems can also be used to reduce power outage time by around 20 per cent and lead to more efficient operation of power plants as during power outage or other failures, the critical infrastructure can be identified immediately.

Instant information

New possibilities for energy transport and distribution provided by Galileo will help utilities control the amount of electricity distributed. The project developers believe that instruments surrounding the grids will be more effectively synchronized the moment a power line breaks or a weakness appears in the grid.

Europe’s utilities are continually integrating their grids for greater energy efficiency and security and the Galileo team believes its new system, which is more suited for critical applications, can enable a more efficient power flow. For example, measurements and perturbations must be time-tagged with errors of less than 0.001 seconds. Electrical energy is not easily stored, and in the case of malfunctions, current or voltage surges propagate along the lines. These surges are sometimes large enough to damage line equipment and cause interruptions in service. For tracing the origin of the problem and deciding on what action to take, time tagging the individual events is mandatory. With Galileo able to deliver grid synchronization at the microsecond level, the fault can be located within metres if not centimetres.

Stelz insists that the applications and related technology for the project will be tailored to commercial demand and has outlined four levels of service that will escalate in accuracy and price. “There will be a separation and categorization of services. The majority will be using an open reference service, however services with integrity and security guarantees will be more expensive due to the licence fees having to be paid to Galileo.”

Ascos will be one of, if not the only, energy sector service providers with the authority to issue a Galileo licence, which is necessary to access the higher levels of accuracy and guarantees.

Urban canyons

While the commercial project will solve many problems that GNSS users have found there are some aspects that remain a challenge.

“A major drawback in this area is the bad quality of existing map material. The currently available GIS infrastructure is still far from bring optimal for highly accurate positioning applications,” reads the HiTec market research document.

Also, the launch of GIGA will be unable improve on the fact that 100 per cent coverage is not a viable prospect in the near term due to the problem of ‘urban canyons’ in city areas that either block or interfere with satellite signals. It is therefore expected that the range of new hardware receivers that will be developed will allow the combined usage of alternative modes of surveying, both GNSS based and terrestrial.

The ultimate aim is for the new receivers to be able to use signals from all three satellite constellations and there should be no problem between GPS and Galileo: “From a technical point of view, Galileo offers similar information as GPS. Therefore Galileo receivers or hybrid GPS/Galileo receivers should quite easily be integrated in time servers and existing IT systems,” says Huck. According to Huck there is an agreement between the USA and the EU of an interoperable signal structure and therefore hybrid GPS/Galileo receivers will be standard. The next step is to ensure the compatibility of Russia’s Glonass system.

“Russia and the GJU (Galileo Joint Undertaking) are working to harmonize the signals or find a common platform. At the moment hardware producers can make a small update, but if this is not solved [harmonized] then updates will not be available. It will be a problem,” says Stelz.

Hardware upgrades

Having just entered the second phase of the four-phase project, service providers and telecommunication companies are developing prototypes and a technology platform to show energy companies how the Galileo system will work. This should be completed by 27 October 2006 and the industry will then be able to see a technical model and some prototype hardware in operation. But, like all complicated projects, this is dependent on a number of variables.

One of the companies developing a prototype receiver for timing and frequency applications, Meinberg Funkuhren, is waiting on more information before it can move on with its developments.

Martin Burnicki, responsible for software development at Meinberg, says: “Unfortunately the final specification of the signals transmitted by the Galileo satellites is not available yet, so we are still missing some basic information we need for the development.”

Figure 2. EU-25 market potential in the field of electricity lines compared to the worldwide market
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Although Galileo and GPS will essentially use the same frequency ranges, their signals will differ, leaving existing GPS receivers unable to track the Galileo satellites without an upgrade. Meinberg plans to develop new receivers so that existing users will just have to replace an older card, and maybe the antenna, in order to benefit from Galileo.

Burnicki says: “The Galileo receiver we are going to develop will provide the same functionality, except that it will be able to derive the accurate time from the Galileo satellites instead of the GPS satellites.”

Global interest

With deadlines rapidly approaching, if the system is to meet its objectives on time to maintain its reputation and not fall into the trap of other pan-European project that have suffered continual delays such as the Eurofighter jet plane, cooperation from outside the EU will be required.

So far technology development deals have been done with China, India, Israel, Morocco, South Korea and the Ukraine and discussions are underway with the governments of Argentina, Australia, Brazil, Canada, Chile, Malaysia and Mexico. It is not yet understood how these countries will use the system, but having registered their interest the project’s strengths have been recognized.

The research provided for the project indicates that greater signal availability is the strongest driver behind the development of related technology. Also cited by those surveyed were the potential cost and savings brought about through guaranteed service accuracy.

“Surveying and energy companies expect Galileo to be superior compared to today’s available GNSS systems in terms of availability, integrity and service guarantees. These variables are an important precondition for companies willing to invest/pay for Galileo services.”

The HiTec document clearly states what is expected and with this being a commercial project jointly led by the private sector it will be in everyone’s interest to ensure this becomes a reality.

As the US and Russian systems modernize in preparation of the launch of the Galileo constellation, utilities should soon have access to a much more comprehensive and effective satellite network that will help provide instant answers to perpetual questions. Company star gazers can look forward to being able to share Galileo’s vision by taking measurements from the greatest aura of knowledge the world has ever known.

How satellite navigation works: The satellites in the constellation are fitted with an atomic clock measuring time very accurately. The satellites emit personalized signals indicating the precise time the signal leaves the satellite. The ground receiver, incorporated for example into a mobile phone, has in its memory the precise details of the orbits of all the satellites in the constellation. By reading the incoming signal, it can thus recognize the particular satellite, determine the time taken by the signal to arrive and calculate the distance from the satellite. Once the ground receiver receives the signals from at least four satellites simultaneously, it can calculate the exact position. Source: EU

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