Saturday, January 24, 2009

NASA Sees the 'Dark Side' of the Sun

An artist's concept of one of the STEREO spacecraft.

Note for my readers who have X-band capability, you can participate in monitoring these spacecraft. More in the storey below-N5FPW

January 23, 2009: Today, NASA researchers announced an event that will transform our view of the Sun and, in the process, super-charge the field of solar physics for many years to come.

"On February 6, 2011," says Chris St. Cyr of the Goddard Space Flight Center, "Super Bowl XLV will be played in Arlington, Texas."

Wait … that's not it.

And on the same day," he adds, "NASA's two STEREO spacecraft will be 180 degrees apart and will image the entire Sun for the first time in history."

STEREO's deployment on opposite sides of the Sun solves a problem that has vexed astronomers for centuries: At any given moment they can see only half of the stellar surface. The Sun spins on its axis once every 25 days, so over the course of a month the whole Sun does turn to face Earth, but a month is not nearly fast enough to keep track of events. Sunspots can materialize, explode, and regroup in a matter of days; coronal holes open and close; magnetic filaments stretch tight and—snap!—they explode, hurling clouds of hot gas into the solar system. Fully half of this action is hidden from view, a fact which places space weather forecasters in an awkward position. How can you anticipate storms when you can't see them coming? Likewise researchers cannot track the long-term evolution of sunspots or the dynamics of magnetic filaments because they keep ducking over the horizon at inconvenient times. STEREO's global view will put an end to these difficulties.

The global view is still two years away. Already, however, the two spacecraft are beaming back over-the-horizon images that have researchers and forecasters glued to their monitors.

"This is a perspective we've never had before," says STEREO mission scientist Lika Guhathakurta of NASA headquarters. "We're now monitoring more than 270 degrees of solar longitude—that's 3/4ths of the star."

"After all these years," she laughs, "we're finally getting to see the dark side of the Sun."

(Editor's note: The Sun has no dark side. That was a solar physics joke.)

STEREO's journey to the "dark side" began on Oct. 25, 2006, when the twin probes left Earth together onboard a Delta II rocket. High above the atmosphere, they separated and headed for the Moon. What happened next was a first in space navigation. The Moon acted as a gravitational slingshot, flinging the two probes in opposite directions—STEREO-A ahead of Earth and STEREO-B behind. They've been spreading apart ever since.

Because of the way the Sun spins (counterclockwise in the diagram above), STEREO-B gets a sneak preview of sunspots and coronal holes before they turn to face Earth—a boon for forecasters.

"I know forecasters at NOAA's Space Weather Prediction Center monitor STEREO-B very closely," says St Cyr. "It lets them know what's coming."

At the moment, STEREO-B enjoys a 3-day look-ahead advantage over Earth-based observatories. This has allowed researchers to predict geomagnetic storms as much as 72 hours earlier than ever before. On several occasions in late 2008, STEREO-B spotted a coronal hole spewing solar wind before any other spacecraft did.

St. Cyr notes that experienced ham radio operators can participate in this historic mission by helping NASA capture STEREO's images. The busy Deep Space Network downloads data from STEREO only three hours a day. That's plenty of time to capture all of the previous day's data, but NASA would like to monitor the transmissions around the clock.

"So we're putting together a 'mini-Deep Space Network' to stay in constant contact with STEREO," says Bill Thompson, director of the STEREO Science Center at Goddard.

The two spacecraft beam their data back to Earth via an X-band radio beacon. Anyone with a 10-meter dish antenna and a suitable receiver can pick up the signals. The data rate is low, 500 bits per second, and it takes 3 to 5 minutes to download a complete image.

So far, the mini-Network includes stations in the United Kingdom, France and Japan—and Thompson is looking for more: "NASA encourages people with X-band antennas to contact the STEREO team. We would gladly work with them and figure out how they can join our network."

The two STEREO spacecraft rank among most sophisticated solar observatories launched by NASA to date. They are equipped with sensors that measure the speed, direction and composition of the solar wind; receivers that pick up radio emissions from explosions and shock waves in the sun's atmosphere; telescopes that image the solar surface and all the tempests that rage there; and coronagraphs to monitor events in the sun's outer atmosphere.

"So, really," says Guhathakurta, "we're not only seeing the sun's dark side, we're feeling, tasting and listening to it as well."

Super Bowl Sunday may never be the same….

Graphics with this story at:

Thursday, January 22, 2009

Severe Space Weather

Auroras over Blair, Nebraska, during a geomagnetic storm in May 2005. Photo credit: Mike Hollingshead/

That's the surprising conclusion of a NASA-funded study by the National Academy of Sciences entitled Severe Space Weather Events—Understanding Societal and Economic Impacts. In the 132-page report, experts detailed what might happen to our modern, high-tech society in the event of a "super solar flare" followed by an extreme geomagnetic storm. They found that almost nothing is immune from space weather—not even the water in your bathroom.

The problem begins with the electric power grid. "Electric power is modern society's cornerstone technology on which virtually all other infrastructures and services depend," the report notes. Yet it is particularly vulnerable to bad space weather. Ground currents induced during geomagnetic storms can actually melt the copper windings of transformers at the heart of many power distribution systems. Sprawling power lines act like antennas, picking up the currents and spreading the problem over a wide area. The most famous geomagnetic power outage happened during a space storm in March 1989 when six million people in Quebec lost power for 9 hours: image.

According to the report, power grids may be more vulnerable than ever. The problem is interconnectedness. In recent years, utilities have joined grids together to allow long-distance transmission of low-cost power to areas of sudden demand. On a hot summer day in California, for instance, people in Los Angeles might be running their air conditioners on power routed from Oregon. It makes economic sense—but not necessarily geomagnetic sense. Interconnectedness makes the system susceptible to wide-ranging "cascade failures."

To estimate the scale of such a failure, report co-author John Kappenmann of the Metatech Corporation looked at the great geomagnetic storm of May 1921, which produced ground currents as much as ten times stronger than the 1989 Quebec storm, and modeled its effect on the modern power grid. He found more than 350 transformers at risk of permanent damage and 130 million people without power. The loss of electricity would ripple across the social infrastructure with "water distribution affected within several hours; perishable foods and medications lost in 12-24 hours; loss of heating/air conditioning, sewage disposal, phone service, fuel re-supply and so on."

"The concept of interdependency," the report notes, "is evident in the unavailability of water due to long-term outage of electric power--and the inability to restart an electric generator without water on site."

The strongest geomagnetic storm on record is the Carrington Event of August-September 1859, named after British astronomer Richard Carrington who witnessed the instigating solar flare with his unaided eye while he was projecting an image of the sun on a white screen. Geomagnetic activity triggered by the explosion electrified telegraph lines, shocking technicians and setting their telegraph papers on fire; Northern Lights spread as far south as Cuba and Hawaii; auroras over the Rocky Mountains were so bright, the glow woke campers who began preparing breakfast because they thought it was morning. Best estimates rank the Carrington Event as 50% or more stronger than the superstorm of May 1921.

"A contemporary repetition of the Carrington Event would cause … extensive social and economic disruptions," the report warns. Power outages would be accompanied by radio blackouts and satellite malfunctions; telecommunications, GPS navigation, banking and finance, and transportation would all be affected. Some problems would correct themselves with the fading of the storm: radio and GPS transmissions could come back online fairly quickly. Other problems would be lasting: a burnt-out multi-ton transformer, for instance, can take weeks or months to repair. The total economic impact in the first year alone could reach $2 trillion, some 20 times greater than the costs of a Hurricane Katrina or, to use a timelier example, a few TARPs.

What's the solution? The report ends with a call for infrastructure designed to better withstand geomagnetic disturbances, improved GPS codes and frequencies, and improvements in space weather forecasting. Reliable forecasting is key. If utility and satellite operators know a storm is coming, they can take measures to reduce damage—e.g., disconnecting wires, shielding vulnerable electronics, powering down critical hardware. A few hours without power is better than a few weeks.

NASA has deployed a fleet of spacecraft to study the sun and its eruptions. The Solar and Heliospheric Observatory (SOHO), the twin STEREO probes, ACE, Wind and others are on duty 24/7. NASA physicists use data from these missions to understand the underlying physics of flares and geomagnetic storms; personnel at NOAA's Space Weather Prediction Center use the findings, in turn, to hone their forecasts.

At the moment, no one knows when the next super solar storm will erupt. It could be 100 years away or just 100 days. It's something to think about the next time you flush.

Sunday, January 18, 2009

Naval Observatory Soon Will Track Time to 100 Trillionths of Second

By John Ohab, Special to American Forces Press Service

The ultra-precise timing technology that enables NAVSTAR Global Positioning Systems and high-speed Internet communication soon may resolve the measure of time to 100 trillionths of a second, according to the world's authority in time-keeping and celestial observation.

"To know when an event occurred, you need a clock. We are that clock," said Geoff Chester, public affairs officer at the U.S. Naval Observatory, the majority contributor to the international determination of time. He explained the development of this new timing technology during yesterday's premier of the Defense Department's "Armed with Science" radio program on

For centuries, clocks have measured seconds through regular, rhythmic oscillations of a pendulum, a swinging weight susceptible to influence by factors such as gravity, temperature, and air viscosity. In the 1950s, scientists began investigating the oscillations of particular atoms as a more precise way to define the second.

"Atomic time is independent of what Earth does," Chester said. "Atomic clocks define time scales in terms of a certain number of oscillations of a certain type of atom that take place in the course of one second. The master clock at the Naval Observatory is an ensemble of dozens of these devices, and we take a weighted average of all of them to determine our base-reference time scale."

Standard atomic clocks measure microwave signals emitted from atoms as they change energy levels. Since 1967, the one-second time interval has been defined as the duration of 9,192,631,770 cycles of radiation corresponding to the transition between two energy levels of the cesium-133 atom.

"We guarantee that no two seconds that come out of here over the course of a year will differ by more than one billionth of a second," Chester said. "Our clock is so precise that it will not gain or lose one second on the order of 3 million years."

To meet the demands of technology and the needs of society, researchers at the U.S. Naval Observatory continue to develop more precise time-keeping systems. By 2010, they hope to release an operational version of their newest clock, known as a "fountain clock," which uses laser beams to induce oscillations of the rubidium atom. This rubidium fountain clock will provide a measure of time accurate to 100 trillionths of a second, about 10 to 100 times more precise than the current master clock.

"Rubidium atoms are smaller and easier to manipulate," Chester explained. "They allow us to keep a much better timescale than what we keep today."

The U.S. Naval Observatory, one of about 50 scientific laboratories concerned with time-keeping, maintains one-third of the operational atomic clocks currently deployed around the world.

In addition to its role in defining and maintaining universal time, the Naval Observatory also acts as a reference point for navigation and communications technologies that affect people's everyday lives. For instance, its ultra-precise time-keeping systems enable computer networks to rapidly and accurately transmit information, and the constellation of satellites used in GPS relies on the master clock to calculate locations on the Earth's surface.

"People ask what time is about," Chester said. "Timing is everything."

NASA debuts Global Hawk autonomous aircraft for Earth science

One of two Global Hawk aircraft that were transferred from the Air Force to NASA in December 2007 will begin missions to support NASA's Science Mission Directorate and the Earth science community. The aircraft, located at the Dryden Flight Research Center at Edwards, Calif., brings a new capability to the science community for measuring, monitoring and observing remote locations of the Earth. The two Global Hawks were the first and sixth aircraft built for the Air Force under the original development program. (NASA photo/Tony Landis)

NASA and the Northrop Grumman Corp. of Los Angeles have unveiled the first Global Hawk aircraft system to be used for environmental science research, heralding a new application for the world's first fully autonomous high-altitude, long-endurance aircraft. The debut took place Jan. 15 at NASA's Dryden Flight Research Center in Edwards, Calif.

NASA and Northrop Grumman are returning NASA's two Global Hawk aircraft to flight this year under a space act agreement signed in May 2008. NASA plans to use the aircraft for missions to support its Science Mission Directorate and the Earth science community that require high-altitude, long-distance airborne capability.

"Today marks the debut of NASA's newest airborne science capability," said Kevin L. Petersen, director of Dryden. "These Global Hawks represent the first non-military use of this remarkable robotic aircraft system. NASA's partnership with Northrop Grumman has made this possible."

The Air Force transferred the Global Hawks to NASA in December 2007. They are among the first seven built in the original Advanced Concept Technology Demonstration program, which the Defense Advanced Research Projects Agency sponsored. Northrop Grumman specialists will share in the use of the aircraft to conduct their own flight demonstrations for expanded markets, missions and airborne capabilities, including integration of autonomous aircraft systems into the national airspace.

Global Hawk can fly at altitudes up to 65,000 feet for more than 31 hours at a time. To date, the aircraft have flown more than 28,000 hours.

The National Oceanic and Atmospheric Administration, or NOAA, also is partnering with NASA to develop this new airborne research tool. NOAA officials are participating in the project management and piloting of the NASA Global Hawks and the development of scientific instruments and future Earth science research campaigns.

"The Global Hawks will provide superb new measurement possibilities for our climate science and applications programs," said Michael Freilich, director of NASA's Earth Science Division in Washington.

"This collaboration is a model for NASA's wide-ranging Earth-observation activities to advance our understanding of Earth as an integrated system, which are critical to developing responses to environmental change here and around the world," he said.

NASA's initial use of the aircraft to support Earth science will be the Global Hawk Pacific 2009 program. This campaign will consist of six long-duration missions over the Pacific and Arctic regions in the late spring and early summer of 2009. Twelve scientific instruments integrated into one of the NASA Global Hawk aircraft will collect atmospheric data while flying high through Earth's atmosphere in the upper troposphere and lower stratosphere.

Global Hawk has many potential applications for the advancement of science, improvement of hurricane monitoring techniques, development of disaster support capabilities, and development of advanced autonomous aircraft system technologies. For example, Global Hawks were used to help monitor wildfires in Southern California in 2007 and 2008.

NASA's Dryden Flight Research Center, located on Edwards Air Force Base in the Mojave Desert of Southern California, is NASA's primary installation for atmospheric flight research. It has supported NASA's technology development efforts in aeronautics, environmental science, space exploration and space operations for more than 60 years.

Powerful Solar Storm Could Shut Down U.S. for Months

A new study from the National Academy of Sciences outlines grim possibilities on Earth for a worst-case scenario solar storm.

Damage to power grids and other communications systems could be catastrophic, the scientists conclude, with effects leading to a potential loss of governmental control of the situation.

The prediction is based in part on a major solar storm in 1859 that caused telegraph wires to short out in the United States and Europe, igniting widespread fires.

See the rest of this copyrighted article on the FoxNews website at,2933,478024,00.html

Saturday, January 17, 2009

Btown Blog Logs - 1/17/2009

Here are the latest active civilian aero freqs intercepted this morning here in Btown.

**Need some help from my readers. Does anyone have any additional information on ATL ARTCC freq 125.825 (RCAG, Sector, etc)?

124.325 ATL ARTCC Hampton GA Ultra High Altitude FL330 and above Sector 23 Clark Hill Sector

124.875 ATL ARTCC Chattanooga TN High Altitude Sector 36 Alatoona Sector

125.025 ATL ARTCC Jonesville SC High Altitude FL330 and above Sector 26 High Rock Sector

125.575 ATL ARTCC Columbus GA High Altitude Sector 10 LaGrange Sector

125.625 ATL ARTCC Owning (Greenville) SC High Altitude Sector 32 Spartanburg Sector

**125.825 ATL ARTCC Unknown RCAG Atlanta ARTCC Discrete: Ultra High Altitude

125.925 ATL ARTCC Crossville (Hinch Mountain) TN High Altitude Sector 39 Burne Sector

128.000 ATL Approach Control - Erlin 5 STAR Arrival/Herko 2 STAR Arrival

128.725 ATL ARTCC Birmingham AL High Altitude Sector 03 Gadsden Sector

132.050 ATL ARTCC Chattanooga TN Low Altitude Discrete: Approach/Departure services for various small airports via this RCAG Sector 05 Dallas Sector

132.975 ATL ARTCC Hickory NC Ultra High Altitude FL330 and above Sector 43 Pulaski Sector

134.075 ATL ARTCC Newport TN Ultra High Altitude FL330 and above Sector 40 Blue Ridge Sector

Congress unprepared for Jan. 20 emergency

By Jordy Yager

Many lawmakers do not know how to use a critical communications system in the event of an emergency during President-elect Obama’s Inauguration.

Despite months of security planning for the Inauguration by various government agencies, a White House-directed phone service that is supposed to be given to every lawmaker for emergency use remains a mystery to many members of Congress.

The chairman of the House Administration Committee, which oversees the security of all House members and staff, has never seen or heard of the tool. “I don’t know anything about it,” said Rep. Robert Brady (D-Pa.). “I’m definitely going to find out, though.”

Brady is far from alone. Eight lawmakers The Hill spoke to on Wednesday said they either were not sure of or did not have the Government Emergency Telecommunications Service (GETS) card, which gives users priority telephone access during emergencies, when traditional phone lines may be disconnected or flooded with calls.

“I don’t know anything about that,” said Rep. Barney Frank (D-Mass.), a committee chairman who has served in the House for nearly 30 years.

Five other members said they had and were familiar with the card, but some of them were unsure how to use it.

The GETS card is one of several emergency preparedness measures taken by the House and Senate sergeants at arms and the House Chief Administrative Office (CAO) to ensure the safety of lawmakers. Lawmakers also are given a card giving them instructions on how to evacuate the Capitol in the event of an emergency.

Lawmakers seem more familiar with that card, as several who were unfamiliar with the GETS knew about the evacuation card.

Still, knowledge of the GETS card could be particularly important on Jan. 20, when most representatives of all three branches of government attend the first black president’s Inauguration.

Without the card, lawmakers might be unable to communicate with emergency personnel to ensure their own safety and the safety of their staffs and any visitors to the Inauguration who are under their care.

They might also be unable to take part in any response to a terrorist attack because of the likelihood that traditional communications lines would be overloaded.

In the event of an emergency, phone service is apt to be interrupted or even inaccessible because of the high volume of people trying to call friends, family and emergency personnel. The GETS system allows for users to supersede this congestion by using an elevated communication highway of sorts.

“GETS is necessary because of the increasing reliance on telecommunications … Recent events have shown that natural disasters, power outages, fiber cable cuts and software problems can cripple the telephone services of entire regions,” reads the GETS website.

On Sept. 11, 2001, lawmakers had major difficulties making calls to their district offices, and then-Rep. Porter Goss (R-Fla.), the chairman of the House Intelligence Committee at the time, had trouble communicating with CIA officials. In the following years, requests for GETS cards surged.

The fact that many lawmakers are unfamiliar with the system isn’t new. A year after the Sept. 11 attacks, then-House Chief Administrative Officer James Eagen testified to Congress that GETS cards had been delivered to all members. But despite that assertion, The Hill in 2006 found that dozens — if not hundreds — of legislators did not have GETS cards in their wallets.

In 2006, then-Sen. Obama told The Hill he did not have a GETS card and asked one of his aides to secure one for him.

The office of the Senate sergeant at arms said it ensures that lawmakers know about the GETS cards.

“We instruct them on what it’s used for, which is for a means of communication if the regular phone system is not available, and whether they choose to use that as their primary [emergency measure] or not is up to them,” said Kimball Winn, the chief information officer for the Senate sergeant at arms.

The CAO declined to comment for this story, and the office of the House sergeant at arms did not return calls.

Still, many lawmakers seem unaware of the cards. Of five members The Hill spoke with who had a GETS card, none could find it in their wallets, and several did not know how to use it, though they said they received instructions at one point.

Surprisingly, members who have been on Capitol Hill for more than 10 years, like Frank and former presidential candidate Rep. Ron Paul (R-Texas), were most unsure of the GETS system.

“I don’t know anything about it,” said Paul at first. “Oh, they might have sent it to me and if they did, I didn’t pay any attention to it.”

Freshman members like Rep. Glenn Nye (D-Va.) and more junior members like Rep. Charlie Dent (R-Pa.), by contrast, said they have been instructed on how to use the calling service and been issued cards with the number.

“I have the card and have had it ever since I was elected,” Dent said. “I keep it in my wallet but I’ve never had to use it.”

With some officials estimating more than 4 million people will attend the Inauguration — the first presidential transfer of power since the United States has been at war and the first since the 2001 terrorist attacks — security officials have taken above-normal measures to ensure the safety of the public and politicians. This transition is likely to leave the country and D.C. more prone to an attack than usual, according to a private report obtained by The Hill last week.

Rep. Michael Capuano (D-Mass.), who chairs the Capitol Security subcommittee, said he had the card but did not know anything about it.

“I was [instructed how to use it] but I don’t remember what it was because I’ve got a cell phone,” said Capuano, who added that he is not very concerned about what he would do in the event of an emergency.

“I’m one member of Congress, so guess what? The world will go on without me.”

Thursday, January 15, 2009

President Announces Declaration For The District Of Columbia

WASHINGTON, D.C. -- The President today declared an emergency exists in the District of Columbia and ordered federal aid to supplement the District's response efforts in support of the 56th Presidential Inauguration. The declaration makes available funding and support for the purposes of ensuring the District of Columbia and the federal government are optimally prepared and postured to respond to the 56th Presidential Inauguration, beginning on January 17 through January 21.

The President's action authorizes the Department of Homeland Security, Federal Emergency Management Agency (FEMA), to provide appropriate assistance for certain emergency protective measures, authorized under Title V of the Stafford Act. FEMA will also be authorized and prepared to coordinate any necessary response efforts, should an emergency arise. Specifically, assistance is available to the District for emergency protective measures that are undertaken to save lives and protect public health and safety. Direct Federal assistance, at 100 percent federal funding will be provided during the period of January 17-21, 2009, and reimbursement of emergency protective measures (Category B), under the Public Assistance program, at 100 percent federal funding for work performed on January 20, 2009. FEMA will reimburse for eligible emergency protective measures performed on January 20, 2009, only if the District has expended on the Presidential Inauguration during the period of January 17-21, 2009, the $15 million appropriated to it for "Emergency Planning and Security Costs" by the Continuing Appropriations Resolution 2009, P.L. 110-329.

FEMA Administrator David Paulison named Donald L. Keldsen the federal coordinating officer for federal coordination operations in the District of Columbia.

The Presidential Inauguration has been designated as a National Security Special Event (NSSE) by the Department of Homeland Security. FEMA's role is to be prepared to respond to a natural disaster, acts of terrorism and other man-made disasters.

FEMA is also taking the following actions to support the 56th Presidential Inauguration.

* FEMA has activated its National Response Coordination Center and Regional Response Coordination Center for FEMA Region III ;
* FEMA's National Incident Management Assistance Team - East has been activated; and
* More than 200 highly trained FEMA employees are supporting the Inauguration at multiple designated locations.

FEMA coordinates the federal government's role in preparing for, preventing, mitigating the effects of, responding to, and recovering from all domestic disasters, whether natural or man-made, including acts of terror.

Sunday, January 11, 2009

CHM Scanning the 56th Presidential Inauguration

If you plan on attending the Prez Inaug next week (personally I wouldn't be within 500 miles of that mess), here is an online PDF guide for scanner radio hobbyist courtesy of the Capitol Hill Monitor group that you might want to bring along.

Saturday, January 10, 2009

Solar Weather Threat To Wired Earth

U.S.-commissioned report sees possibility of 'space weather [hurricane] Katrina' that could cost up to $2 trillion. See full story\

NY State Said to Be Close to Dropping Police Radio Project


State officials are close to canceling a $2 billion contract to build a statewide wireless network for emergency agencies after critical tests on the network failed late last year, according to state officials briefed on the results.

Lawyers for the vendor, M/A-COM, a subsidiary of Tyco Electronics, sent the state a letter on Friday threatening to sue if officials follow through on their plan to shut down the project, which was intended to improve radio communications throughout the state, but particularly in remote areas where police agencies have trouble talking to one another.

State officials, though, were said to be determined to shut down the project because it was unclear, after a pilot program in two counties and nearly $52 million in expenditures, that M/A-COM's system would ever work as expected. A major problem has been the difficulty and unanticipated cost of installing radio towers in remote, mountainous areas, according to the officials and technical experts, who spoke
anonymously because the contract dispute is at a delicate juncture.

To finish the project, state officials decided that considerably more money would have to be spent at a time when the state is expected to have large budget deficits. At the same time, the state cannot embark on a new network project, no matter what the cost, until it untangles itself from its current contract, one state official said.

"The state is reviewing the letter from the attorneys for M/A-COM," said Morgan Hook, a spokesman for Gov. David A. Paterson. "We anticipate making a decision in short order that will be based on our factual analysis of the system's performance."

Lawyers from Weil, Gotshal & Manges, the firm representing M/A-COM, said in their letter that it was "patently obvious" that the state was determined to cancel the contract because of political and financial pressure and was using technical issues as a pretext for the cancellation.

The State Office for Technology, which has overseen the network's construction since 2005, "has acted in bad faith throughout the past year" and has made "defamatory and untrue statements regarding M/A-COM's performance under the contract," the letter said.

The largest technology contract in state history, the network has had problems from the start, according to state officials. In August, the state sent a default letter to M/A-COM ordering it to fix deficiencies or face cancellation. A decision to cancel the project has seemed imminent since then, and some state officials, and lawyers for the contractor, have spoken of it as a fait accompli.

The original plan, conceived after the attacks of Sept. 11, 2001, was designed to link emergency agencies from the tip of Long Island to Niagara Falls via a series of radio towers. The network was meant to cover 95 percent of New York's area and 97 percent of its roadways, including some of the most remote parts of the state.

The Office for Technology is looking at other methods, including Internet-based communications and cellphone technology, that are said to be more cost-effective and could provide more reliable and cheaper service than the radio technology called for in the original contract.

Daniel M. De Federicis, the president of the Police Benevolent Association of the New York State Troopers, said that until a statewide radio network has been built, his organization would push for improvements in the present patchwork of networks.

"The lack of an operating statewide wireless network is beyond frustrating," Mr. De Federicis said in a statement. "The P.B.A. cannot stress enough that this creates life-and-death situations for police officers, and we are running out of synonyms for `ineptness' to describe the situation."

The project, which is now two years behind schedule, has faced questions from the outset. Critics questioned the Pataki administration's decision to award the contract to M/A-COM, whose bid was $1 billion less than its closest major competitor, Motorola.

The radio system was supposed to be working in Erie County and neighboring Chautauqua County by June 2007, but repeated problems caused the City of Buffalo to quit the statewide system in December 2007.

M/A-COM missed other operational deadlines, finally prompting the Office for Technology to declare in August that the company was in default. The office gave the company 45 days to fix 19 deficiencies.

In their letter Friday, lawyers for the company said that all technological issues had been addressed and that any delays were the fault of the state.

During an 11-day test period in July, the network was found to be inoperable for nearly 44 hours, far more than the 53 minutes of downtime per year authorized by the state.

Since the state default letter was issued in August, some workers hired to build the network have been laid off, and several subcontractors have stopped work on the network.

In late August, the state comptroller, Thomas P. DiNapoli, issued a report criticizing the plan. The report noted that the "network testing was not properly planned or implemented, and the needs of the public safety user agencies were not fully taken into account during the network design and development process."

Separately, M/A-COM agreed to pay the state $4 million after auditors found that the company had billed for services that had not been provided and charged for some equipment that had already been paid for.

A spokesman for M/A-COM, Steven A. Greenberg, said on Friday, "We remain ready to hear from the state, as we have since testing concluded last fall."