Committee (2nd Day)

Part of Digital Economy Bill [HL] – in the House of Lords at 3:15 pm on 12th January 2010.

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Photo of Earl Attlee Earl Attlee - Shadow Minister (Maritime and Shipping), Shadow Minister 3:15 pm, 12th January 2010

My Lords, it may be for the convenience of the Committee if I speak to Amendment 30 at this point. My amendment is properly grouped with my noble friend's, but it raises a slightly different though highly relevant point.

GPS satellite navigation systems are by now fairly ubiquitous, but there is much misunderstanding about how they work and the robustness or otherwise of the system. I intend to give the Committee a brief introduction to GPS, but it will be a gross simplification of an ingenious system.

A constellation of satellites has been launched by the US Government which operates the system as a free good for the world, although the primary motivation was obviously military. GPS provides highly accurate positioning and timing. Ground stations operated by the US Government track, communicate with and control the satellites. The ground stations predict and provide high-accuracy orbit and clock information for each satellite. These data are transmitted to each satellite. Each satellite transmits its high-accuracy orbit and clock information as well as coarse orbit and clock information for all the other satellites to the receiver- that is, your GPS hand-held unit or your sat-nav in your car.

The clever bit is as follows. The satellites continuously transmit their time-stamped signals. These travel at the speed of light-it is not instantaneous-at about 300 kilometres per millisecond. This means that the distance from the satellite to the receiver can be calculated accurately. The receiver uses signals from several satellites. By performing something akin to simultaneous equations, the receiver can determine position and height above sea level. Also, and most importantly, the time can be calculated to within around 40 nanoseconds, which is not very long since a nanosecond is a billionth of a second.

So far, so good; but there is a problem. The GPS satellite emits its signal at a power of about 100 watts, which is roughly equivalent to a light bulb, from 20,000 kilometres away. Therefore the signal received on earth is vanishingly weak and can be swamped by, for example, natural atmospheric conditions during high solar activity. It is also easily swamped by locally generated signals. This has already occurred accidentally in San Diego and elsewhere due to the malfunction of legitimate equipment. But it can also be done with malign intent using a GPS jammer, which needs only about one watt of power to be effective. Details of the necessary technology and sources of supply are inevitably available on the internet. They are often bought to overcome a vehicle's security system or to bypass a rental vehicle's charging system. GPS jamming can cause obvious difficulties for navigation and positioning systems, but the loss of the timing signal could be extremely inconvenient for certain specialised operations.

GPS is a space-based system, but there is also a terrestrial system called e-Loran, which should not be confused with the older Loran systems. E-Loran is nearly as accurate as GPS and provides a good timing capability. The system of operation is basically the same as for GPS, but the transmitters are land-based and have outputs in the multi-kilowatt range. However, the principle of measuring the time of flight of the radio signal remains the same, and because much higher powers can be used with a terrestrial system, it is much harder to jam than GPS. Further, since the e-Loran system operates on a different frequency range, it is unlikely to fail at the same time as GPS.

The same cannot be said for the EU Galileo system. I can well recall being told by Ministers at the Dispatch Box that Galileo can be used for safety-critical applications, and I believed them. But the problem is that Galileo operates using more or less the same system and on the same frequency as the US-operated GPS system. I have also now found out that it can be interfered with very easily, and I do not believe that the science and technology has changed significantly over recent years. So my first question for the Minister is this: in the light of the ready availability of GPS jammers and the associated technology, is he of the opinion that Galileo can still be used for safety-critical applications or those that affect critical national infrastructure? If he is not of that opinion, why have we expended huge amounts of effort and money on Galileo? What can Galileo do that a combination of the US GPS and e-Loran systems cannot?

Opposition amendments are sometimes thought to be unworkable, unnecessary or wrecking. My amendment could fall into the unnecessary category, as I know that the Government are already on to the case and that the noble Lord, Lord West, has been heavily involved, particularly with e-Loran.

Last November, I attended a series of GPS jamming trials off Tynemouth in the north-east which had been organised by Trinity House. At one point, my own hand-held GPS suggested that I was in Romania. More disturbing was that the GPS on the "Galatea", Trinity House's own vessel, was inaccurate, by only a few kilometres, but it was nevertheless believable. The dangers are obvious. Of course, I am not naive. I expect that Trinity House would like to run the UK part of the e-Loran system, and it already has a trial transmitter in Cumbria. However, it does not seem to me that e-Loran is a particularly expensive system in comparison with a space-based one, especially as there is already a legacy Loran infrastructure in place with 72 per cent of the world's 50 busiest ports covered by Loran.

To sum up my point, why have we invested, and continue to invest, in Galileo as a second celestial system when e-Loran is much simpler, cheaper and does not have the same vulnerabilities? I hope that the Minister can tell us how he proposes to meet the challenges I have identified.


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