Europes GPS System is starting to Take Shape

  |   By

Following years of wrangling and uncertainty, the European equivalent to the GPS (Global Positioning System), is finally beginning to take shape. The European Galileo system, which will complement the current USA system, is a step closer to completion.

Galileo, which will be the first operational global navigational satellite system (GNSS) outside the United States will provide positioning information for satellite navigation machines and timing information for GPS NTP servers (Network Time Protocol).

The system, being designed and manufactured by the European Space Agency (ESA) and the European Union (EU) and when it is operational it is expected to improve the availability and accuracy of timing and navigation signals transmitted from space.

They system has been dogged in political wrangling and uncertainty since its inception nearly a decade ago. Objections from the US that they will lose the ability top switch off GPS in times of military need; and economic restraints across Europe, meant that the project was nearly shelved several times.

However, the first four satellites are being finalised in a laboratory in southern England. These In-Orbit Validation (IOV) satellites will form a mini-constellation in the sky and prove the Galileo concept by transmitting the first signals so the European system can become a reality.

The rest of the satellite network should follow shortly after and. Galileo should eventually comprise over 30 of them which means that users of satellite navigation systems of GPS NTP time servers should get quicker fixes be able to locate their positions with an error of one metre compared with the current GPS-only error of five.

Time Synchronization Using the GPS Network

  |   By

The GPS (Global Positioning System) systems has revolutionized navigation for pilots, mariners and drivers a like. Nearly every brand new car is sold with an inbuilt satellite navigation system already installed and similar detachable devices continue to sell in their millions.

Yet the GPS system is a multi purpose tool thanks mainly to the technology it employs to provide navigational information. Each GPS satellite contains an atomic clock which signal is used to triangulate positioning information.

GPS has been around since the late 1970’s but it was only in 1983 that is stopped from being purely a tool of the military and was opened up to allow free commercial access following an accidental shooting down of a passenger airliner.

To utilise the GPS system as a timing reference, a GPS clock or GPS time server is required. These devices usually rely on the time protocol NTP (Network Time Protocol) to distribute the GPS time signal that arrives via the GPS antenna.

GPS time is not the same as UTC (Coordinated Universal Time) which is normally used  NTP for time synchronization via radio transmissions or the internet. GPS time did originally match UTC in 1980 during its inception but sine that time there have been leap seconds added to UTC to counteract the variations of the earth’s rotation, however the on-board satellite clocks are corrected to compensate for the difference between GPS time and UTC, which is 17seconds, as of 2009.

By utilising a GPS time server an entire computer network can be synchronized to within a few milliseconds of UTC ensuring that all computers are safe, secure and able to deal effectively with time sensitive transactions.

Facts of Time

  |   By

From wristwatches to atomic clocks and NTP time servers, the understanding of time has become crucial for many modern technologies such as satellite navigation and global communications.

From time dilation to the effects of gravity on time, time has many weird and wonderful facets that scientists are only beginning to understand and utilise. Here are some interesting, weird and unusual facts about time:

•    Time is not separate from space, time makes up what Einstein called four dimensional space time. Space time can be warped by gravity meaning that time slows down the greater the gravitational influence.  Thanks to atomic clocks, time on earth can be measured at each subsequent inch above the earth’s surface. That means that every bodies feet are younger than their head as time runs slower the lower to the ground you get.

•    Time is also affected by speed. The only constant in the universe is the speed of light (in a vacuum) which is always the same. Because of Einstein’s famous theories of relativity anybody travelling at close to the speed of light a journey to an observer that would have taken thousands of years would have passed within seconds. This is called time dilation.

•    There is nothing in contemporary physics that prohibits time travel both forward and backwards in time.

•    There are 86400 seconds in a day, 600,000 in a week, more than 2.6 million in a month and more than 31 million in a year. If you live to be 70 years old then you will have lived through over 5.5 billion seconds.

•    A nanosecond is a billionth of a second or roughly the time it takes for light to travel about 1 foot (30 cm).

•    A day is never 24 hours long. The earth’s rotation is speeding up gradually which means the global timescale UTC (coordinated universal time) has to have leap seconds added once or twice a year. These leap seconds are automatically accounted for in any clock synchronization that uses NTP (Network Time Protocol) such as a dedicated NTP time server.

Heroes of Time

  |   By

Chronology – the study of time- has provided science and technology with some incredible innovations and possibilities. From atomic clocks, NTP servers and the GPS system, true and accurate chronology has changed the shape of the world.

Time and the way it is counted has been a preoccupation of mankind since the earliest civilisations. Early chronologists spent their time trying to establish calendars but this proves to be more complicated than first imagined primarily because the earth takes a quarter of a day more than 365 days to orbit the sun.

Establishing the right number of leap days was one of the first challenges and it took several attempts at calendars until the modern Gregorian calendar became adopted by the globe.

When it came to monitoring time at a smaller level great advances were made by Galileo Galilei who would have built the first pendulum clock if only his death hadn’t interrupted his plans. Pendulums were finally invented by Christiaan Huygens and provided the first true glimpse of accurately monitoring the time throughout the day.

The next steps in chronology couldn’t take place though until we had a better understanding of time itself. Newton (Sir Isaac) had the first ideas and had the notion time was absolute” and would flow “equably” for all observers. This would have been an obvious idea to Newton as many of us regard time as unchanging but it was Einstein in his special theory of relativity that proposed that in fact time wasn’t a constant and would differ to all observers.

It was Einstein’s ideas that proved correct and his model of time and space paved the way for many of the modern technologies we take for granted today such as the atomic clock.

However, chronology doesn’t stop there, timekeepers are constantly looking for ways of increasing accuracy with modern atomic clocks so precise they would not lose a second in millions of years.

There are other notable figures in the modern world of chronology too. Professor David Mills from the University of Delaware devised a protocol in the 1980’s to synchronise computer networks.

His Network Time Protocol (NTP) is now used in computer systems and networks all over the world via NTP time servers. A NTP server ensures computers on opposite sides of the globe can run exactly the same time.

Worlds Most Famous Clock Reaches 150

  |   By

It’s one of the world’s most iconic land marks. Standing proudly over the Houses of Parliament, Big Ben celebrates its 150th birthday. Yet despite living in an age of atomic clocks and NTP time servers, it is one of the most used timepieces in the world with hundreds of thousands of Londoners relying on its chimes to set their watches to.

Big Ben is actually the name of the main bell inside the clock that creates the quarter hourly chimes but the bell didn’t start chiming when the clock was first built. The clock began keeping time on 31 May 1859, while the bell didn’t strike for the first time until July 11.

Some claim the twelve tonne bell was named after Sir Benjamin Hall the Chief Commissioner of Works who worked on the clock project (and was said to be a man of great girth). Others claim the bell was named after heavyweight boxer Ben Caunt who fought under the moniker Big Ben.

The five-tonne clock mechanism works like a giant wristwatch and is wound three times a week. Its accuracy if in tuned by adding or removing old pennies on the pendulum which is quite far removed from the accuracy that modern atomic clocks and NTP server systems generate with near nanosecond precision.

While Big Ben is trusted by tens of thousands of Londoners to provide accurate time, the modern atomic clock is used by millions of us every day without realising it. Atomic clocks are the basis for the GPS satellite navigation systems we have in our cars they also keep the internet synchronised by way of the NTP time server (Network Time Protocol).

Any computer network can be synchronised to an atomic clock by using a dedicated NTP server. These devices receive the time from an atomic clock, either via the GPS system or specialist radio transmissions.

The Atom and Time keeping

  |   By

Nuclear Weapons, computers, GPS, atomic clocks and carbon dating – there is much more to atoms than you think.

Since the beginning of the twentieth century mankind has been obsessed with atoms and the minutiae of our universe. Much of the first part of the last century, mankind became obsessed with harnessing the hidden power of the atom, revealed to us by the work of Albert Einstein and finalised by Robert Oppenheimer.

However, there has been much more to our exploration of the atom than just weapons. The studying of the atoms (quantum mechanics) has been at the root of most of our modern technologies such as computers and the Internet.  It is also in the forefront of chronology – the measuring of time.

The atom plays a key role in both timekeeping and time prediction. The atomic clock, which is utilised all over the world by computer networks using NTP servers and other technical systems such as air traffic control and satellite navigation.

Atomic clocks work by monitoring the extremely high frequency oscillations of individual atoms (traditionally caesium) that never changes at particular energy states. As caesium atoms resonate over a 9 billion times every second and never alters it its frequency it makes the m highly accurate (losing less than a second every 100 million years)

But atoms can also be used to work out not just accurate and precise time but they can also be utilised in establishing the age of objects. Carbon dating  is the name given to this method which measures the natural decay of carbon atoms. All of us are made primarily of carbon and like other elements carbon ‘decays’ over time where the atoms lose energy by emitting ionizing particles and radiation.

In some atoms such as uranium this happens very quickly, however, other atoms such as iron are highly stable and decay very, very slowly. Carbon, while it decays quicker than iron is still slow to lose energy but the energy loss is exact over time so by analysing carbon atoms and measuring their strength it can be quite accurately ascertained when the carbon originally formed.

Reported GPS Fears Should Not Affect Time Synchonisation

  |   By

Following recent media reports on the lack of investment in the USA’s Global Navigation Satellite System – GPS (Global Positioning System) and the potential failure of navigational receivers in recent years, time synchronisation specialists, Galleon Systems, would like to ensure all their customers that any failure of the GPS network will not affect current GPS NTP time servers.

Recent media reports following a study by the US government’s accountability office (GAO), that concluded mismanagement and a lack of investment meant some the current number of 31 operational satellites may fall to below 24 at times in 2011 and 2012 which would hamper its accuracy.

However, the UK’s National Physical Laboratory are confident that any potential problems of the GPS navigation facilities will not affect timing information utilised by GPS NTP servers.

A spokesman for the UK’s National Physical Laboratory confirmed that timing information should be unaffected by any potential future satellite failure.

“There is estimated to be a 20% risk that in 2011-2012 the number of satellites in the GPS constellation could drop below 24 at times.

“If that were to happen, there could be a slight reduction in the position accuracy of GPS receivers at some periods, and in particular they might take longer to acquire a fix in some locations when first powered up. However, even then the effect would be a degradation of performance, rather than complete failure to operate.

“A GPS timing receiver is unlikely to be affected significantly since, once it has determined its position when turned on, every satellite it observes provides it with useful timing information. A small reduction in the number of satellites in view should not degrade its performance much.”

MSF Outage 11 June NPL Maintenance

  |   By

The UK’s MSF signal broadcast from Anthorn, Cumbria and utilised by UK NTP server users is be turned off for a four hour period on 11 June for scheduled maintenance. The MSF 60 kHz time and frequency standard will be off between 10.00 and 14:00 BST (9:00 – 13:00 UTC).

Users of NTP time servers that utilise the MSF signal should be aware of the outage but shouldn’t panic. Most network time servers that use the Anthorn system should still function adequately and the lack of a timing signal for four hours should not create any synchronisation problems or clock drift.

However, any testing of time servers that utilise MSF should be conducted before or after the scheduled outage. Further information is available from NPL.

Any network time server users that require ultra-precise precision or are feel temporary loss of this signal could cause repercussions in their time synchronisation should seriously consider utilising the GPS signal as an additional means of receiving a time signal.

GPS is available literally anywhere on the planet (as long as there is a good clear view of the sky) and is never down due to outages.

For further information on GPS NTP server can be found here.

Computers, Communications, Atomic Clocks and the NTP Server

  |   By

Time synchronisation on computer networks is often conducted by the NTP server. NTP time servers do not generate any timing information themselves but are merely methods of communicating with an atomic clock.

The precision of an atomic clock is widely talked about. Many of them can maintain time to nanosecond precision (billionths of a second) which means they won’t drift beyond a second in accuracy in hundreds of millions of years.

However, what is less understood and talked about is why we need to have such accurate clocks, after-all the traditional methods of keeping time such as mechanical clocks, electronic watches and using the rotation of the Earth to keep track of the days has proved reliable for thousands of years.

However, the development of digital technology over recent years has been nearly solely reliant on the ultra high precision of an atomic clock. One of the most widely used applications for atomic clocks is in the communications industry.

For several years now telephone calls taken in most industrialized countries are now transmitted digitally. However, most telephone wires are simply copper cables (although many telephone companies are now investing in fibre optics) which can only transmit one packet of information at a time. Yet telephone wires have to carry many conversations down the same wires at the same time.

This is achieved by computers at the exchanges switching from one conversation to another thousands of times every second and all this has to be controlled by nano-second precision otherwise  the calls will become out of step and get jumbled – hence the need for. Atomic clocks; mobile phones, digital TV and Internet communications use similar technology.

The accuracy of atomic clocks is also the basis for satellite navigation such as GPS (global positioning system). GPS satellites contain an onboard atomic clock that generates and transmits a time signal. A GPS receiver will receive four of theses signals and use the timing information to work out how long the transmissions took to reach it and therefore the position of the receiver on Earth.

Current GPS systems are accurate to a few metres but to give an indication of how vital precision is, a one second drift of a GPS clock could see the GPS receiver be inaccurate by over 100 thousand miles (because of the  huge distances light and therefore transmissions take in one second).

Many of these technologies that depend on atomic clocks utilise NTP servers as the preferred way to communicate with atomic clocks making the NTP time server one of the most crucial pieces of equipment in the communication industries.

The NTP Time Server Essential Network Protection

  |   By

There are a myriad of hardware and software methods of protecting computers. Anti-virus software, firewalls, spyware and routers to name but a few yet perhaps the most important tools for keeping a network safe is often the most overlooked.

One of the reasons for this is that the network time server’s often referred to as the NTP time server (after the protocol Network Time Protocol) primary task is time synchronisation and not security.

The NTP server’s primary task is to retrieve a time signal from a UTC source (Coordinated Universal Time) which it then distributes it amongst the network, checking the clock on each system device and ensuring its running in synchronisation with UTC.

Here is where many network administrators fall down. They know that time synchronisation is vital for computer security. Without it, errors can not be logged (or even spotted) network attacks can’t be countered, data can be lost and if a malicious user does get into the system it is near impossible to discover what they were up to without all machines on a network corresponding to the same time.

However, the NTP server is where many network administrators think they can save a little money. ‘Why bother?’ ‘They say, ‘when you can log on to an Internet NTP server for free.’

Well, as the old saying goes there is no such thing as a free lunch or as it goes a free source of UTC time. Using internet time providers may be free but this is where many computer networks leave themselves open to abuse.

To utilise an internet source of time such as Microsoft’s, NIST or one of those on the NTP pool project may be free but they are also outside a networks firewall and these is where many network administrators come unstuck.