Tag: gps

SOLAR FLARE, DON’T TRUST YOUR GPS TODAY

A massive solar storm is due to arrive at Earth early Thursday, and is expected to shake the globe’s magnetic field while expanding the Northern Lights.

A giant blast of plasma spat from the sun at as much as 4 million miles per hour Tuesday — by some measures the largest solar event since late 2006 — and it could lead to serious issues on Earth, forcing some planes to reroute, knocking out power grids, and blacking out radios.

The sun unleashed the cosmic double whammy late March 6, erupting with two major flares to cap a busy day of powerful solar storms, Space.com reported. One of the flares is the most powerful solar eruption so far this year.

“Super Tuesday? You bet!” joked Joseph Kunches, a space weather scientist with the National Oceanic and Atmospheric Administration (NOAA).

The storm grew as it raced outward from the sun, expanding like a giant soap bubble, scientists said.

“It’s hitting us right in the nose,” said Kunches.

Both of the huge flares ranked as X-class storms, the strongest type of solar flares the sun can have. They followed several weaker, but still powerful, sun storms on Tuesday and came just days after another major solar flare on Sunday night.

“By some measures this is the strongest one since December of 2006,” Kunches explained. Solar activity has already led to an R3 level radio blackout on NOAA’s space weather scale, he explained, a midstrength event on a scale that reaches to R5. Such effects are caused by X-ray emissions from the sun.

The bigger effects will hit the planet over the next 24 hours.

 

“Power grid operators have all been alerted.”

– Joseph Kunches, NOAA space weather scientist

 

For one thing, geomagnetic storms — disturbances in the geomagnetic field that surrounds the planet — should hit the G3 level, midway up the scale. That could lead to surges in power lines (a major problem for power companies) and issues with satellites.

“Power grid operators have all been alerted, as well as the regulatory agencies that all pay attention to this,” Kunches said.

GPS users will also be affected because of the highly charged atmosphere; it’s very possible that certain types of applications will be interrupted, specifically highly precise calculations and the high-frequency communications that airplanes rely upon.

Indeed, some polar flights have already been affected, he said.

“Some have already taken action to reroute to ensure their [high-frequency communication],” Kunches said.

Solar radiation storms could reach as high as S4, he noted, which could cause astronauts on the International Space Station to seek shelter from the heightened radiation levels associated with such a storm.

These effects should last about 24 hours, probably lingering overnight into the early morning hours on Friday, pending another eruption — “and we think there will be more coming,” Kunches said.

The upside? Some areas may experience a wonderful display of the Northern Lights.

“It’s the treat that we get when the sun erupts,” he said.

Read more: http://www.foxnews.com/scitech/2012/03/07/sun-fires-off-2-huge-solar-flares-could-impact-weather-on-earth/#ixzz1oWYBLXqN

LIGHTSQUARED

Sail-World.com News

 

LightSquared and the USA’s GPS system – is the alarm warranted?

7:21 PM Sat 11 Feb 2012

 

 

pastedGraphic.pdf
Spectrum policy – necessary for all nations’    .

 

On January 31 Sail World reported that ‘alarm and anger were growing in the marine industry as LightSquared threatened the USA’s GPS system’ (See Sail-World story). In a previous story Garmin was quoted as saying ‘If GPS were compromised it would affect every GPS-dependent piece of equipment.’ 

 

Now keen sailor, eminent Doctor of Engineering and Spectrum policy expert, Michael J. Marcus, has weighed into the discussion with some salient facts:

 

As a long time sail boat owner (Jeanneau 32 Attalia based near Annapolis) and a radio spectrum policy wonk (Wi-Fi and Bluetooth began from rules I initiated at FCC in the early 1980s), I have been troubled by statement such as these made in Sail-World’s article on the subject.

 

However, these pale compared to statements made by Garmin at the beginning of the article or by BoatUS, the major boating membership association in the US to which I belong.

 

First, what is the origin of this controversy? Cellphones and broadband are becoming key parts of our societies and economies. Today’s systems are rapidly running out of capacity. While the cellular industry exaggerates additional spectrum as the only possible cure for this capacity problem, it certainly is a key tool. FCC and its counterparts in other countries are all trying to find more radio spectrum for such services.

 

About 20 years ago it appeared that ‘mobile satellite service’ or MSS, e.g. Inmarsat and Iridium, would be a key telecom service everywhere the world and that global spectrum had to be reserved for it. Advances in both terrestrial and satellite communications have proved this to be wrong in a key aspect: MSS spectrum is now very lightly used in populated areas and new technology allows the same spectrum to be used for MSS in rural areas and over oceans while used for cellular-like services in populated areas – effective ‘recycling’ otherwise unused spectrum in areas where it is sorely needed!

 

One of the MSS bands involved is just below the GPS L1 band used by commercial GPS units. In the US, FCC has authorized use of this band for terrestrial cellular services (FCC jargon for this is Auxiliary Terrestrial Component or ATC) since 2003 and the company now called LightSquared has been authorized since 2004.

 

Now there is some dispute about details of the early FCC decisions and how many base stations were allowed under them, but it is clear that base stations were allowed next to the GPS band since 2003 and that the civil GPS supplier community paid little attention to the fact that GPS would be having a new neighbor with much stronger signals in some places than the original MSS signals.

 

Real receivers of all types do not have infinite ability to reject strong adjacent band signals. Such rejection requires careful design and the amount of rejection possible increases with time as filter technology improves. As long as the MSS band had no cellular base stations in it, little rejection was needed and GPS manufacturers did not have to incorporate the latest filter improvements which incurs both design and retooling costs.

 

Thus it appears that the GPS industry has not pressed the filter manufacturers for the latest technology as the cellular systems in nearby bands have. As a result many GPS receivers have a lingering vulnerability to strong adjacent band signals that results from GPS manufacturers ignoring policy changes made in the US almost a decade ago!

 

 

pastedGraphic_1.pdf
Spectrum chart –  .. .

In June 2011 after an initial rounding of GPS receiver testing, LightSquared changed its plans to move farther away from the GPS L1 signal to 1526-1536 MHz which is 23 MHz (almost 4 US TV channels or almost 3 European TV channels) away from the lower edge of the GPS L1 band at 1559 MHz. (See Chart left)

 

Rather than admit any responsibility for this and focus on a reasonable transition scheme, the GPS industry has chosen to make what a friend who is a GPS pioneer has described as a Jonestown-style ‘suicide pact’. (The Garmin quote at the start of this article is an indication of this approach.) The industry has enlisted lawyers and PR firms and a broad variety of ‘fellow travellers’, such as BoatUS, to say the ‘sky is falling’.

 

It has even convinced the Air Force general who is responsible for the GPS satellites to testify that the LightSquared system would impact military GPS systems that were supposed to be jam resistant. Without getting too technical, if such a 100 watts transmitter 23 MHz away from the edge of the GPS band could impact military GPS receivers, imagine what a bad guy could do with a similar or stronger jammer transmitter inside the GPS band? And it is well known that simulated GPS signals are even more effective jammers, watt for watt, than noise or cellular-like signals.

 

Military sources have told me that the general’s testimony on military equipment susceptibility actually dealt with obsolescent equipment from the early days of GPS that is still in inventory in small quantities and vulnerable to any undesired signal.

 

But real boaters know something that lawyers and PR firms apparently don’t: boats float on water.

 

The LightSquared/GPS controversy, especially after June 2011 move farther away from the GPS band, is an issue with GPS receivers that both have inadequate adjacent band rejection and are within a few hundred meters of a possible LightSquared base station – not a typical boating scenario but never mentioned in BoatUS material on the subject.

 

In trying to use the public spectrum resource for the maximum overall public good national regulators like FCC regularly have to repurpose bands as technology and society’s needs change. Such repurposing sometimes impacts both incumbent users of the band, not so in this particular case, or users of neighboring bands.

 

For example, several times in the last few decades TV spectrum in many countries has been repurposed for mobile communications. The usual solution is a transition scheme that balances the costs and benefits of the change and allows affected incumbents users time to adapt to the new change.

 

The GPS industry and its fellow travelers appear to have no interest in such a transition that might make them admit to design errors in the past decade. Such a viewpoint could result in spectrum gridlock that prevents future repurposing of all bands. This issue is further complicated because the issues lies squarely on the fault line between the jurisdiction of FCC and a separate coequal agency, NTIA, that regulates federal government spectrum use.

 

In a reasonable transition scheme the base stations could be designed to prevent high signals in all navigable waters during a period in which GPS receivers improve – but the GPS manufacturers and BoatUS don’t want to discuss transitions and the overall public interest in spectrum use. They have dug themselves into policy hole and demand only total victory!

 

How did BoatUS reach this position and continue to maintain it after the LightSquared proposed to move further away from GPS? Multiple inquiries to BoatUS from this member have received no clear response other than vaguely siding with Coast Guards and industry. Did BoatUS use knowledgeable members in reaching and reviewing its decision? Like the boy who cried wolf, expressing unfounded fears to government regulators harms the credibility of the boating community in other regulatory decisions that could be more important to boaters.

 

Sail World readers outside the US need not be concerned about this issue as it is purely a domestic US issue and individual countries have the discretion to make such decisions within their own territory under the terms of Article 4.4 of the ITU Radio Regulations. 

 

However, all GPS users might want to press GPS manufacturers about whether they are using interference rejection technology comparable to what cell phones in nearby bands use.

 

GPS units are now sold in multimillion unit quantities so they can afford contemporary technology filters that usually cost under $1 in such production quantities. (Note these are marginal costs for new units, retrofitting existing units is usually much more expensive.)

 

But decide for yourself what the issues are in this controversy and how we got to where we are. Here is information from the opposing sides:

 

LightSquared

 

GPS Industry

 

…and for masochists & policy wonks:

All FCC filings received:

 

Early filings (Before 06/28/2011)

 

Later filings (After 06/28/2011)

 

 

About Michael J. Marcus: 

Michael Marcus is both a sailor and a technical spectrum policy specialist. He has a doctorate in electrical engineering from MIT, worked almost 25 years at FCC on spectrum policy issues, and was elected a Fellow of the Institute of Electrical and Electronics Engineers for his leadership in spectrum policy. For more information about Dr Marcus, including his complete CV, please go to Marcus Spectrum Solutions LLC 

LIGHTSQUARED

With a little help from a friend, Andy, who alerted me to the followup on this story.

 

Agency tasked with overseeing military and government spectrum use says interference with other devices is unavoidable.

LightSquared suffered a possibly fatal blow today when the FCC said it would indefinitely suspend the company’s effort to build a national wireless broadband network using satellite spectrum.

The National Telecommunications and Information Administration, a Department of Commerce agency tasked with overseeing military and government spectrum use, determined that LightSquared’s interference with other devices, including GPS devices, was unavoidable.

“Based on NTIA’s independent evaluation of the testing and analysis performed over the last several months, we conclude that LightSquared’s proposed mobile broadband network will impact GPS services and that there is no practical way to mitigate the potential interference at this time,” the NTIA said in a letter (PDF) to the Federal Communications Commission.

Based on those findings, the FCC said it would “suspend indefinitely” the startup’s conditional waiver to operate. “The commission clearly stated from the outset that harmful interference to GPS would not be permitted,” the FCC said. “Consequently, the commission will not lift the prohibition on LightSquared.”

LightSquared responded by saying that it disagreed with the NTIA’s conclusions, arguing that they were based on a “severely flawed testing process.” However, the company “remains committed to finding a resolution with the federal government and the GPS industry to resolve all remaining concerns. LightSquared is confident that the parties will continue the on-going efforts to explore all engineering options and alternatives to find a solution to this difficult issue.”

The FCC granted LightSquared a waiver in 2011 to tap its spectrum, which is supposed to be used for satellite and terrestrial communications, for terrestrial only use. As a condition of this waiver, the FCC said that there can’t be any harmful interference between LightSquared and others in nearby spectrum.

But the GPS industry claims that LightSquared’s network will interfere with its receivers. Meanwhile, LightSquared acknowledges potential interference issues, and it’s already agreed to not use the spectrum closest to the GPS bands. It’s also demonstrated how filters can be used to mitigate interference.

Read more: http://news.cnet.com/8301-1035_3-57378009-94/fcc-suspends-lightsquared-waiver-over-gps-interference/#ixzz1mW12oWMB

NOT SCIENCE FICTION

We knew it was too good to be true, right?

I’m referring to GPS, a phenomenon so utterly amazing that decades after its invention it still seems more fantasy than reality. After wandering the seas for millennia never quite sure of where in the watery world they were, sailors were given the gift of precise knowledge of their boat’s position on command.

When this gift first arrived, some of the skeptics among us really did say it was too good to be true. Don’t depend on it, they warned. The satellites could go haywire or fall out of the sky.

Well, the satellites are doing just fine and GPS remains reliable and accurate, not to mention cheap and available in all kinds of mundane electronic gizmos, but the prophecy that the gift could be taken away is starting to seem credible.

Thanks to an odd pairing of ruthless capitalism and weak-kneed government regulation, GPS navigation could be rendered untrustworthy and, as an auxiliary disaster, the millions of GPS receivers now in use could be made obsolete.

I wouldn’t blame readers who don’t know about this for thinking I’m writing science fiction. Why would anyone do anything to undermine one of the greatest inventions of the space age and why would the government approve it? Read on.

A company funded by a hedge-fund billionaire proposes to build a broadband cell-phone communications network it calls LightSquared. To do that, the firm needs a waiver from the Federal Communications Commission because its license is limited to low-power satellite communication and its plan calls for high-power land-based signals.

The FCC granted the waiver. That news was received with shock and horror by the makers and users of GPS devices and organizations that represent them, and for good reason. The LightSquared network has the potential to destroy GPS as we know it.

That could happen because the frequencies LightSquared would operate on are next to those used by GPS. Satellites in the GPS system send signals with minuscule amounts of power. LightSquared signals would be much stronger. To use a wind analogy, if GPS signals are a zephyr, LightSquared’s would be a Category 5 hurricane.

The LightSquared signals could in effect blow GPS signals out of the sky.

The FCC acknowledged that possibility in January 2011 when it issued the waiver with a condition—it would only take effect if the LightSquared network did not interfere with GPS.

In a tacit admission that its network would indeed be a threat to disable GPS, LightSquared announced the problem could be solved simply by installing filters on receivers and criticized GPS makers for not figuring this out. In October LightSquared introduced a filter made by a vendor that it said would protect receivers at a cost of $50 to $300 each.

GPS experts doubt the filters will work. And even if they did, how could the millions of GPS devices in use in the United States be retrofitted with the filters? And why should their owners have to pay to make the GPS service they depend on immune to mischief resulting from a company’s plan to profit from irresponsible use of the public’s airwaves?
Here’s a more perplexing question: How did a threat to GPS get this far?

By year’s end, voices opposing LightSquared had grown to a full-throated roar from a disparate army of GPS defenders.

Yet as this is written LightSquared remains undaunted. It confirmed that with a bold move in late December, sending the FCC a petition asking for a declaratory ruling endorsing its right as a radio spectrum licensee to put its system in place. It is making no claim it won’t interfere with GPS; in fact, it’s saying the GPS industry has no right to ask the FCC for protection from LightSquared.

I guess this shouldn’t be surprising. LightSquared is backed by Philip Falcone and his hedge fund Harbinger Capital Partners. Falcone is a bold kind of guy.

The Wall Street Journal reported that the Securities and Exchange Commission is trying to ban him from the securities industry because of misconduct involving subprime mortgages. (It also reported that the chairman of the FCC said the agency would consider such misconduct in deciding on the LightSquared license petition, an encouraging development.)

Naturally, I’m mad as hell about the threat to GPS. But also bewildered. I get it about LightSquared. There’s money to be made in 4G broadband communication. But what is the FCC thinking? How could this protector of the public’s airwaves even consider approving a system that interferes with GPS?

That question is so baffling some are suggesting the answer is political skulduggery. Some of Falcone’s political contributions have gone to Democratic Party causes, leading some Republicans in Congress to say this paved the way for kind treatment from the FCC under the Obama administration.

Falcone told Politico.com he’s a registered Republican and has given more to Republicans than Democrats and did not ask for or receive political favors.

You almost wish crony capitalism were at work here. At least that would make some sense out of the FCC’s eggshell-walking around LightSquared. Otherwise, how can the regulators not understand a conflict so simple it can be expressed in two short sentences:

We don’t need another cell-phone network. We do need GPS.