Posts Tagged ‘gps satellites’

LightSquared and GPS community have no solution

Feb 4, 2012 , ,

We’ve been talking about the battle between LightSquared and the GPS industry. The heart of the problem is that the spectrum for 4G network and the GPS signals are right next to each other and compared to GPS signals 4G signals are way way stronger, possibly causing interference.

In a report published June last year did indeed say this was the case.

“For the originally defined LightSquared spectrum deployment scenarios, GPS-based operations are expected to be unavailable over entire regions of the country at any normal operational aircraft altitude.”

So LightSquare’s solution was to use the dark orange band to the left to stay as far from regular GPS receivers as possible. This combined with better management of emissions from transmitter would save the sat nav systems used in aircrafts and cars.

However the super accurate high end GPS receivers are still very susceptible to interference because their radio frequency filters are very “liberal” and sometimes the augmentation signals used by them are actually transmitted from frequencies in the mobile satellite band.

I guess the problem is actually receivers not sticking to their allowed frequency since the receiver side of things is not really regulated by FCC.

However if you want more technical insight do read up on this article too.

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China no longer needs your GPS

Jan 5, 2012 , ,


If you don’t already know this – current GPS system used all over the world for navigation and many other things is a US based system. But China can now use their own version of satellite positioning system called Beidou.

It’s not quite worldwide yet but it is already offering positioning and timing services over China and other surrounding areas. This is done with only 10 satellites. By 2020 they’ll have 35 satellites in orbit which will provide a worldwide coverage.

China’s military is one of the biggest of the world and with Beidou they’re cutting their dependance on U.S. Their navigation system will offer 10 meter accuracy for civilians and an undisclosed level of accuracy for military purposes.

This is better US’ current system but with GPSIII America is planning to catch up with modern times.

Images shown are from Analytical Graphics, Inc. which shows that Beidou satellites provide regular coverage over China and South China Sea, but they currently provide very little to no coverage elsewhere in the world.

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Qualcomm goes dual core with GPS receiver

Dec 28, 2011 , ,

Qualcomm’s new SnapDragon processors now support both GPS and Glonass satellites. This means now instead of 27 satellites your phone can look up an additional 24 satellites for a grand total of 51 satellites. This will be available on the Qualcomm SnapDragon S2, S3, S4 processors. The dual core functionality won’t use up too much battery – it will only look for GLONASS satellites when the need arises. When both are in service you can get down to 2 meters of accuracy and get a position fix a lot faster. Apparently T-Mobile’s Galaxy SII phone already uses this processor.

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China adds a new satellite to their own Beidou navigation system

Dec 6, 2011 , ,


China at 5:07 a.m. on Friday, sent their 10th navigation satellite to orbit in an effort to complete their own navigation system known as Beidou. The satellite was strapped to a Long March-3A carrier rocket. Beidou is currently functional but only provides position information for China and its surrounding areas as opposed to the whole globe unlike US’ GPS.

Beidou is on track with its progress. The plan is to have 30 satellites circling the Earth by the year 2020. The start date for the whole thing was 2000.

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Europe’s Galileo Satellite takes off

Oct 24, 2011 , ,

EU finally managed blast of a couple of Galileo satellites into orbit on Friday from the French Guiana. These left Earth’s gravitational field on top of a Soyuz rocket and they will be followed by two more next year. 30 satellites will be deployed in total and the expected date of operation for the Galileo satellite positioning system is 2014. The project had some funding problems along the way but the economic impact should be 90 billions Euros for the next 20 years.

Galileo has the most accurate atomic clock on board that is good for one second in three million years.

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LightSquared showcases yet another “solution”

Oct 19, 2011 , ,

Trying to win the battle on spectrum wars LightSquared recently partnered with new technology companies to develop filtering devices to retrofit or replace antennas to overcome signal interference problems.

One of these companies was Javad GNSS, another is PCTEL, and another addition is now Partron America which apparently developed a filtering component for only $6.

According to LightSquared they have a solution to resolve issues with 99.75 of all devices on which they spent $100 million. They also claim the 400 million cell phones and auto GPS navigation systems that are currently in use are already compatible with LightSquared network.

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fight between LightSquared and GPS industry continues

Oct 3, 2011 , ,

LightSquared had a press release come out couple of days ago flaming the wars between them and the GPS industry. LightSquared is saying GPS industry knew about the possible problems that may be caused by the use of adjacent frequencies for about a decade.

They say the GPS industry has known about all of the issues since 2005 but they didn’t get their act together to build inexpensive filters into GPS receivers that would keep their devices from reaching into our spectrum. Instead the GPS industry just chose to lobby against LightSquared instead of putting together a plan in the last eight years or so.

We’re not sure how they plan on doing this but LightSquared is saying they’re willing to get rid of the interference problem for 99.5 percent of all devices for an additional $100 million cost to them.

Now LightSquared says:

Who pays for the remaining devices that need a fix? Does the GPS industry believe it bears no fiscal responsibility for a problem that is of its own making? Or will it act responsibly and do as other industries have done when they go to market with a deficient device – offer a recall and fix the problem at its own expense?

You can read the whole release here.

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GPS OCX on way

Sep 27, 2011 ,


Raytheon finished design review for the GPS Next Generation Operational Control System (GPS OCX), which means now they know cost estimates and delivery schedule. It was review by the U.S. Air Force Space and Missile Systems Center’s (SMC) GPS Directorate. The whole program is supposed to meet MIL-STD-1521B standards which will allow them continue with completion of the next phase of development in preparation for GPS III launch in 2014.

In case you are wonderin GPS OCX is the next generation operational gateway service for providing secure, accurate and reliable navigation and timing information to support military, commercial and civil users. GPS OCX is the integrator between ground, space and user segments of GPS.

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Russion GLONASS in action in New York

Sep 8, 2011 , ,


If you have a smartphone it probably has a GPS receiver module from Qualcomm which looks for US owned GPS satellites in orbit. Soon this will change and those Qualcomm receivers will start looking for Russian made GLONASS satellites too – yes very unAmerican – providing a lot quicker and accurate position fix. This will specially come in handy for those urban jungles like New York where your current setup relies heavily on cell phone towers to figure out your approximate location.

The interesting fact is GLONASS satellites mostly focus on northern latitudes (think location of Russia) which provides a lot better reception in northern countries such as Canada and northern states of U.S.

Just like GPS you’re using right now, GLONASS won’t cost you a penny however you’ll have to buy a new phone – possibly next year – that has a new Qualcomm recevier which can listen for both GLONASS and GPS satellites.

One of the writers at PCMag had a chance to see a demo unit in action in New York. They went to 28th St. in midtown Manhattan where’s there’s plenty of concrete blocking view of the sky. First they let the phone look for satellites using only GPS and it only got two – which is not enough for a position fix. And then they turned on the ‘use GLONASS’ button or whatever they had and started seeing 14 satellites. They immediately had a location fix.

Russia already has GLONASS powered phones and in the U.S. Garmin’s new eTrex seem to be the only end-consumer products that uses both GPS and GLONASS.

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fixing GPS altitude accuracy

Aug 23, 2011 ,


If you’ve ever used your GPS navigation system in your vehicle or just on your smartphone you know it can pinpoint your location dead on in horizontal space. The same can not be told for altitude though. GPS is not very accurate when it comes to figuring out how high you are. This has been known issue since GPS has been around but finally some research scientists are bringing a solution to the table.

Dorota Grejner-Brzezinska, a professor Ohio State University and her colleagues at University of Warmia and Mazury in Poland are developing a software that can bring centimeter accuracy to altitude calculations. It is quite complicated but in the heart of the problem is the atmospheric changes that effect the time it take for GPS signals to reach ground based receivers. So her and her team tested receivers tested some GPS receivers at different altitudes and distances from each other – and tested their in-house software. One of their algorithms provided accurate location, including the height of the receivers, 97% of the time…

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