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In a recently released paper, the respected analytics firm London Economics determined that the presence of backup systems at the Denver and Dallas Fort Worth airports prevented any noticeable impacts on air travel despite each having experienced a disruption of GPS signals for 24 hours or more. By contrast, recent GPS interference at an airport without a backup system caused scheduled air service to be canceled until an alternative to GPS was established.

Also important to the lack of impact at Denver and Dallas was that the signals interfering with GPS, with a few minor exceptions, only impacted aircraft in the air.

GPS is essential for the safe and efficient movement of aircraft and support vehicles on the ground at airports, as well as the transport of crews, passengers, supplies, and cargo to and from airports, communication systems, and numerous other services.

Backups needed for both air and ground

Previous work by London Economics has shown that disruption of GPS for these ground functions would likely cause numerous flight delays and cancellations. Delays in the arrival of flight crews, passengers and supplies, for example, would quickly upset flight schedules. If this happened at a major airport, such as Denver or Dallas Fort Worth, disruptions could ripple through the entire air transport system. Wide-spread delays, cancellations and schedule adjustments would bog down air travel across the nation, if not the world.

The incident in Denver was caused by an accidental transmission from a government installation on Jan. 21. 2022. It impacted aircraft within approximately 50 nautical miles of the airport and lasted 33 hours before the source was identified and turned off.

The Dallas incident began on Oct. 17, 2022, and affected aircraft within about 110 nautical miles. It continued for 24 hours before ending on its own. The source has never been identified.

Reducing aviation backups may be a bad idea

In addition to recognizing the value of terrestrial navigation systems for aviation, the London Economics paper cautions about moves in the United States and Europe to “rationalize” these systems by reducing their number. In the event of longer or widespread GPS disruptions, the impact of an insufficient number of terrestrial systems could be significant. The cancellation of air service to an airport in Estonia because of chronic GPS jamming is used in the paper as a cautionary tale.

Instead of reducing the number of old backup systems, London Economics suggests policymakers consider establishing more widely available sources of terrestrial PNT. Taking a fresh look might identify alternative PNT sources for aviation that could also be used by other critical infrastructures. Perhaps even in consumer applications as well.

U.S. government representatives were approached for consultation and comment for this paper and expressed their willingness to participate. Unfortunately, they were unable to obtain permission to do so.

London Economics’ work on this effort was commissioned by the Resilient Navigation and Timing Foundation.

The paper “Aviation GPS Incidents Show Importance of Backup Systems. Policy Makers Take Note.” can be accessed from the foundation’s online library here.

<p>The post Study: GPS disruptions in aviation show importance of backups first appeared on GPS World.</p>

Gen. David Thompson

Join the Resilient Navigation and Timing Foundation for a reception with the President’s National Space-based Positioning, Navigation, and Timing Advisory Board on April 23 at The Antlers Hotel in Colorado Springs. The event begins at 6:00 PM. General David Thompson, U.S. Space Force (retired) will discuss his experience as the first Vice Chief of Space Operations, the state of GPS, and the future of PNT.

For more information and to RSVP, contact inquiries@RNTfnd.org by April 17.

<p>The post Join the upcoming Resilient Navigation and Timing Foundation reception first appeared on GPS World.</p>

Matteo Luccio

On December 5, in Houston, at a reception hosted by the Resilient Navigation and Timing Foundation to celebrate GPS’ 50th anniversary, I had the honor of publicly interviewing Dr. Bradford Parkinson for 45 minutes. When I asked him how GPS today differs from the design that emerged from the Lonely Halls meeting he chaired 50 years ago this past September, he replied, proudly, that “there is no fundamental difference.” Recently, he recalled, he pulled out for the first time in 20 years a handheld Trimble EnsignGPS — “It was one of those little devices that got shipped to the Iraq War,” he noted —, cleaned its contacts, changed its batteries, turned it on, and was immediately able to navigate. “The point of the story,” Parkinson said, “is that evidently it still works.”

When I asked him what he considered to be the most significant impact of GPS on society, he said it was “also probably the most perilous: kids today just take it for granted. They know where they are.”

Taking GPS for granted, however, is not limited to kids today. It is a pervasive attitude throughout our society, including sectors of the federal government that ought to know better. That is why a recurrent theme throughout the 29th meeting of the National Space-Based Positioning, Navigation, and Timing Advisory Board, on December 6 and 7, which I attended, was raising the alarm about the fact that GPS is falling behind Galileo and BeiDou.

“We must attack this mindset [that GPS is] the Gold Standard and everything is OK. It is not OK,” said Admiral Thad Allan, a former Commandant of the U.S. Coast Guard, who chairs the PNT Advisory Board. Perhaps, he suggested, it is time to declare that GPS is only meeting “the Pewter Standard” for GNSS. “That will get the attention of somebody who does not understand this.”

Parkinson, in emphasizing the urgency of the problem, said that he currently counts eight areas in which GPS is falling behind its GNSS counterparts, including:

• L5, the go-to signal particularly for civilian aviation, is not yet activated and will not be until the next three satellites are activated, which will likely not happen for at least another year.
• The Next Generation Operational Control System (OCX), the future version of the GPS control segment, is not yet operational.
• GPS does not have a satellite-based high-accuracy service (HAS). On this, he said, “Everyone is moving out except us.”
• GPS lacks anti-spoofing authentication, which Galileo has.

Additionally, “every one of these things has an enormous lead time,” Parkinson warned.

“As an advisory group, we are only as effective as the willingness of the system that we are advising to act on what we say,” Allan pointed out. The Advisory Board spent the final portion of its meeting discussing how to structure the agenda and products of its next couple of meetings to get these issues with GPS the attention they deserve and require. Stay tuned.

Click to watch the full interview 

Matteo Luccio | Editor-in-Chief

mluccio@northcoastmedia.net

<p>The post The rearview camera and the head-up display first appeared on GPS World.</p>

Dana Goward, President of the Resilient Navigation and Timing Foundation, introducing Brad Parkinson and Matteo Luccio, GPS World EIC. (Image: RNTF)

On December 5, in Houston, Texas, at a gala event to celebrate the 50^th anniversary of GPS hosted by the Resilient Navigation and Timing Foundation, Matteo Luccio, Editor-in-Chief of GPS World, interviewed Brad Parkinson.

Here are two excerpts from the interview:

How does GPS today differ from the design that came out of the Lonely Halls meeting 50 years ago this past September?

Well, I’m very proud of what happened because, to my knowledge, there is no fundamental difference. Basically, that fundamental design has held up. … As a matter of fact, I still have one of the old Trimble handhelds, it’s called an EnsignGPS. It was one of those little devices that got shipped to the Iraq War. The other day, I pulled it out, batteries were kind of crummy, I got those squared away and went out, sure enough and navigated. I probably hadn’t pulled it out in at least 20 years. The point of the story is that evidently it still works.

What do you consider the most significant impact of GPS on society?

Well, the most significant impact is also probably the most perilous: kids today just take it for granted. They know where they are.

Watch the full interview below. 

<p>The post Celebrating 50 years of GPS: An evening with the father of GPS first appeared on GPS World.</p>

UK begins UAV deliveries

Image: Screenshot of video by BBC

Royal Mail and UAV company Skyports have launched the Orkney I-Port operation to distribute letters and packages between the Orkney Islands, Scotland, reported the BBC. In partnership with the council’s harbor authority and Scottish airline Loganair, mail will be transported from Royal Mail’s Kirkwall delivery office to the city of Stromness in Orkney. UAVs will then carry items to the islands of Graemsay and Hoy, where postal staff will complete the delivery routes. The UAV service will initially operate for three months and may continue on a permanent basis under existing regulatory frameworks due to Orkney’s unique landscape and the proximity of the islands to one another. The UAV service aims to improve service levels and delivery times to Graemsay and Hoy, as weather and geography typically cause disruption to delivery services. The use of UAVs to deliver mail also may bring significant safety improvements by ensuring that postal workers can deliver between ports without risk.

GNSS is taking a hike, literally

Image: Aleksandar Georgiev/iStock/Getty Images Plus/Getty Images

In July, officials in Taichung City, Taiwan, launched a GNSS-based app to aid lost hikers and to mitigate risk associated with outdoor activities in the area’s mountainous region, reported Tapei Times. The app was developed by the Taichung Fire Bureau in response to a surge in outdoor activities after the COVID-19 pandemic restrictions were lifted and, subsequently, an increase in medical emergencies linked to mountain activities. Wi-Fi towers have been built at major trailheads such as Toukeshan, Anmashan, Fushoushan and Snow Mountain to supplement the app as well as to help facilitate UAV deployment to find lost hikers.

Lidar reveals Mayan city

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In a biological preserve in Mexico’s Campeche state, a team of archaeologists have documented pyramids, palaces, a ball court and other remains of an ancient city they call Ocomtún, reported The New York Times. Archeologists surveyed the site for six weeks in May and June, finding 50-foot-tall structures resembling pyramids, as well as pottery and Mayan engravings they believe date to between 600 AD and 900 AD. The team determined the city was likely abandoned more than 1,000 years ago. Surveying of the area has been revolutionized over the past decade by lidar — allowing researchers to survey densely forested areas that are difficult to explore on foot. Archeologists were able to use airborne lasers to pierce through dense vegetation and reveal the ancient structures and human-modified landscapes beneath.

Hundreds of UAVs down

Image: Chesky_W/iStock / Getty Images Plus/Getty Images

More than 350 UAVs were lost during a practice light display show in Melbourne, Australia, on July 14, ahead of a scheduled performance for the opening of the women’s World Cup. The UAVs appeared to stop mid-show and plummet into the Yarra River. Divers have since fished out hundreds of the UAVs. According to the Resilient Navigation and Timing Foundation, the likely cause of the mass-crash was interference with GPS signals.

<p>The post Seen & Heard: Lidar reveals Mayan city, UK begins UAV deliveries first appeared on GPS World.</p>

Image: Chesky_W/iStock / Getty Images Plus/Getty Images

More than 350 UAVs were lost during a practice light display show in Melbourne, Australia, on July 14, ahead of a scheduled performance for the opening of the women’s World Cup.

The UAVs appeared to stop mid-show and plummet into the Yarra River. Divers have since fished out hundreds of the UAVs.

According to the Resilient Navigation and Timing Foundation, the likely cause of the mass-crash was caused by interference with GPS signals. This incident shows that having multiple and robust navigation sources is important for safe UAV operation.

<p>The post Hundreds of UAVs lost during Melbourne show first appeared on GPS World.</p>

Credit: YinYang/E+/Getty Images

The same 91 signers also sent an identical letter to President Biden.

 April 24, 2023 

Dear Senators and Members of Congress:

Last year, many of the undersigned wrote in reflection of the unprecedented opposition to the Federal Communications Commission’s (FCC’s) Ligado Order (1) across the vast federal and commercial user base of Global Positioning System (GPS), satellite communications and weather forecasting services. Three years after adoption of the Order, as eight petitions for reconsideration remain pending, (2) we again urge you to work together with the FCC to stay and ultimately set aside the Order. (3) Critically, this is now necessitated by the crucial, previously unavailable information that was produced at the direction of Congress: the independent technical review undertaken by the National Academies of Sciences, Engineering, and Medicine (NAS) (4) analyzing the potential interference issues related to the Ligado Order.

We greatly appreciate your administration’s opposition to the Ligado Order and commitment that the National Telecommunications and Information Administration (NTIA), on behalf of the executive branch, will continue to actively pursue its petition for reconsideration of the Order. (5) As you know, the pending petitions for reconsideration convincingly demonstrate that the Ligado Order is legally and factually deficient. In the pending petitions, parties showed that the Ligado Order is fundamentally flawed, incompatible with the FCC’s rules and inadequate in protecting incumbent services from the harmful interference from Ligado’s proposed operations. This substantial documentation, among many other concerns from federal and commercial users, resulted in Congress enacting bipartisan legislation in consecutive years after the FCC’s adoption of the Ligado Order, mandating NAS’s independent technical review and requiring the Department of Defense (DoD) to brief federal representatives across the government “at the highest level of classification” on the potential for widespread harm from Ligado’s proposed terrestrial operations. (6) On this basis alone, the FCC should stay the Order in an acknowledgement that it clearly did not account for the full, real-world risk of harm associated with a nationwide terrestrial deployment in the L-band.

While the pending petitions have a strong likelihood of success on their own merits, the FCC’s rules and the public interest now require the FCC to reconsider the Order in response to the extensive analysis in the NAS Report. (7) This new, previously unavailable information presented in the Congressionally-mandated independent technical review confirms that Ligado’s proposed terrestrial operations would cause harmful interference (8) at significant ranges to incumbent L-band services across a broad range of deployment scenarios. This is consistent with the well-supported and robustly documented analyses and determinations of the federal government, (9) including fourteen federal agencies and departments, (10) and commercial parties (11) alike. Importantly, as concisely stated by DoD and detailed in the NAS Report, “[t]he terrestrial network authorized by [the Ligado Order] will create unacceptable harmful interference for DoD missions. The mitigation techniques and other regulatory provision [sic] in [the Ligado Order] are insufficient to protect national security missions.”(12)

The unequivocal conclusions of the NAS Report constitute the exact type of previously unavailable information that the FCC’s rules (13) dictate must be addressed on reconsideration. Indeed, NTIA stated on behalf of the executive branch that the NAS Report “offers the [FCC] an important opportunity to reconsider Ligado’s Authorization.”(14) We therefore urge you to work with the FCC to address the harm from Ligado’s proposed terrestrial network to critical GPS, satellite communications, and weather forecasting services by staying the Order, addressing the previously unavailable information contained in the NAS Report, and resolving the pending petitions for reconsideration.

Sincerely,

AccuWeather, Inc.

Aerospace Industries Association

Agricultural Retailers Association

Airborne Public Safety Association

Aircraft Electronics Association

Aircraft Owners and Pilots Association

Airlines for America

Alabama Agricultural Aviation Association

ALERT Users Group

Allied Pilots Association

Air Line Pilots Association, International

American Geophysical Union

American Meteorological Society

American Rental Association

American Road & Transportation Builders Association

American Weather and Climate Industry Association

Arizona Agricultural Aviation Association

Arkansas Agricultural Aviation Association

Associated Equipment Distributors

Association for Uncrewed Vehicle Systems International

Association of Aerial Applicators Washington

Association of Equipment Manufacturers

Association of Marina Industries

Association of Montana Aerial Applicators

Aviation Spectrum Resources, Inc.

BoatU.S.

California Agricultural Aircraft Association

Cargo Airline Association

CNH Industrial

Coalition of Airline Pilots Associations

CoBank

Colorado Agricultural Aviation Association

EarthScope Consortium

Florida Agricultural Aviation Association

General Aviation Manufacturers Association

GeoOptics, Inc.

George Washington University

Georgia Agricultural Aviation Association

Helicopter Association International

Idaho Agricultural Aviation Association

Illinois Agricultural Aviation Association

Indiana Agricultural Aviation Association

International Air Transport Association

Iowa Agricultural Aviation Association

Iridium Communications Inc.

Kansas Agricultural Aviation Association

Land Improvement Contractors of America

Lockheed Martin Corporation

Louisiana Agricultural Aviation Association

Marine Retailers Association of the Americas

Michigan Agricultural Aviation Association

Microcom Environmental

Minnesota Agricultural Aircraft Association

Mississippi Agricultural Aviation Association

Missouri Agricultural Aviation Association

Narayan Strategy

National Agricultural Aviation Association

National Air Carrier Association

National Business Aviation Association

National Cotton Council

National Society of Professional Surveyors

National Weather Association

Nebraska Aviation Trades Association

NetJets Association of Shared Aircraft Pilots

New Mexico Agricultural Aviation Association

North Carolina Agricultural Aviation Association

North Dakota Agricultural Aviation Association

Northeast Agricultural Aviation Association

Ohio Agricultural Aviation Association

Oklahoma Agricultural Aviation Association

Oregon Agricultural Aviation Association

Pacific Northwest Aerial Applicators Alliance

PlanetiQ

Recreational Boaters of California

Resilient Navigation and Timing Foundation

Seafarers International Union

South Dakota Aviation Association

Southeast Aero Cultural Fair

Space Science and Engineering Center at the University of Wisconsin-Madison

Subsurface Utility Engineering Association

Tennessee Aerial Applicators Association

Texas Agricultural Aviation Association

The Airo Group, Inc.

The Semaphore Group

Trimble Inc.

U.S. Geospatial Executives Organization

University Corporation for Atmospheric Research

USA Rice

Vertical Flight Society

Westwind Helicopters

Wisconsin Agricultural Aviation Association

(1) Ligado Amendment to License Modification Applications, IBFS File Nos. SES-MOD-20151231-00981, SAT-MOD-20151231-00090, and SAT-MOD-20151231-00091, Order and Authorization, 35 FCC Rcd 3772 (2020) (“Ligado Order” or “Order”).

(2) More than twenty parties in total signed petitions for reconsideration of the Ligado Order and all of these petitions remain pending before the FCC. See Petitions for Reconsideration of the National Telecommunications and Information Administration; the Air Line Pilots Association, International; the American Road & Transportation Builders Association, the American Farm Bureau Federation, and the Association of Equipment Manufacturers; the Joint Aviation Petitioners; Iridium Communications Inc., Flyht Aerospace Solutions Ltd., Aireon LLC, and Skytrac Systems Ltd.; Lockheed Martin Corporation; Trimble Inc.; and the Resilient Navigation and Timing Foundation, IB Docket Nos. 11-109 & 12-340 (all filed on or about May 22, 2020). The ten “Joint Aviation Petitioners” consist of the Aerospace Industries Association, the Aircraft Owners and Pilots Association, Airlines for America, Aviation Spectrum Resources, Inc., the Cargo Airline Association, the General Aviation Manufacturers Association, the Helicopter Association International, the International Air Transport Association, the National Air Transportation Association and the National Business Aviation Association.

(3) The Commission should also not proceed with any companion rulemakings causing harmful interference to weather forecasting and hydrology services that could result in Ligado deployments, particularly in light of the analysis and recommendations presented in the “Spectrum Pipeline Reallocation 1675–1680 MHz Engineering Study (SPRES) Program Report. See Allocation and Service Rules for the 1675-1680 MHz Band, Notice of Proposed Rulemaking, 34 FCC Rcd 3352 (2019); U.S. Department of Commerce. National Oceanic and Atmospheric Administration. National Environmental Satellite Data Information Service. Spectrum Pipeline Reallocation 1675–1680 MHz Engineering Study (SPRES) Program Report. Silver Spring, MD: NESDIS, October 2020 (public release August 2022).

(4) National Academies of Sciences, Engineering, and Medicine, Analysis of Potential Interference Issues Related to FCC Order 20-48 (2022), https://doi.org/10.17226/26611 (“NAS Report”).

(5) Letter from Gina Raimondo, Secretary of Commerce, U.S. Dept. of Commerce, to The Honorable James M. Inhofe, ranking member, U.S. Senate Committee on Armed Services (June 22, 2021) (reiterating the NTIA’s position opposing the Ligado Order).

(6) William M. (Mac) Thornberry National Defense Authorization Act (“NDAA”) for Fiscal Year 2021, Pub. L. 116-283, 134 Stat. 4074 § 1663; NDAA for Fiscal Year 2022, Pub. L. 117-81, 135 Stat. 1541 § 1613.

(7) These statements are based on the publicly available portions of the NAS committee’s work. In addition, NAS prepared a classified annex, which further details the risks of Ligado’s proposed terrestrial network and additionally warrants FCC action.

(8) The term “harmful interference” is herein used to describe the results of the NAS Report. In turn, the undersigned believe the results of the NAS Report dictate that the FCC must reach the legal conclusion that Ligado’s operations would cause harmful interference under the FCC’s rules.

(9) See, e.g., National Telecommunications and Information Administration Reply to Ligado Networks LLC’s Opposition to Petitions for Reconsideration or Clarification, IB Docket Nos. 11-109 & 12-340, at 10 n.26 (filed June 8, 2020); U.S. Department of Transportation, Global Positioning System (GPS) Adjacent Band Compatibility Assessment, Final Report (Apr. 2018) (“DOT ABC Report”),

(10) See Memorandum from Thu Luu, Executive Agent for GPS, Department of the Air Force, to IRAC Chairman (Feb. 14, 2020).

(11) See, e.g., Letter from J. David Grossman, Executive Director, GPSIA, to Marlene H. Dortch, Secretary, FCC, IB Docket Nos. 11-109 et al., at 6 (Sept. 17, 2020); Letter from Bryan N. Tramont, Counsel to Iridium Communications Inc., to Marlene H. Dortch, Secretary, Federal Communications Commission, IB Docket Nos. 11-109 et al. (Jan. 19, 2022); Update to 2016 Technical Assessment of Ligado User Terminal Interference to Iridium attached to Iridium Communications Inc. et al., Petition for Reconsideration, IB Docket Nos. 11-109 et al. ( May 22, 2020).

(12) NAS Report at 6, 73.

(13) 47 C.F.R. § 1.106(c)(2).

(14) Press Release, NTIA, NTIA Statement on National Academies of Sciences Report (Sept. 9, 2022).

<p>The post Vast coalition seeks reversal of Ligado Order first appeared on GPS World.</p>

Photo: U.S. Fish and Wildlife Service

The Arctic National Wildlife Refuge spans almost 20 million acres. It is home to a vast array of wildlife from tiny pollinating flies to giant grizzly and polar bears.

It also has oil. Lots of oil.

Getting that oil out of the ground and to market would create jobs and benefit commerce. It would also harm the environment. Some wildlife would suffer.

Many argue the long-term harms of drilling outweigh the short-term benefits. The Biden administration agrees and has banned drilling to protect the refuge’s environment and wildlife.

The administration has taken a similarly conservative approach to preserving the spectrum environment for satellites.

Like the previous administration, it has urged the Federal Communications Commission (FCC) to not allow Ligado Networks’ use of frequencies adjacent to spectrum assigned to GPS and Iridium Communications. The concern is that Ligado’s more powerful transmissions will harm some existing users.

A recent report by the National Academies of Sciences, Engineering and Medicine validated that concern. As is the case with many complex environmental issues, the total number of impacted individuals, and the total negative impact to the nation, are unknown. They may be unknowable.

As an independent agency, the FCC gets recommendations from, but does not report to, the administration. To date it has not been swayed by formal appeals from the executive branch, nor by those from numerous industry and non-profit groups, to rescind its decision allowing Ligado to operate.

Like other agencies making environmental decisions, the commission should use the “precautionary principle” when thinking about new uses and users. It is a well-recognized and systematic method of linking science and public policy.

More than “better safe than sorry,” the precautionary principle has four major tenets:

• increasing public participation in decision making
• shifting the burden of proof to the proponents of an activity
• taking preventive action in the face of uncertainty
• exploring a wide range of alternatives to possibly harmful actions.

The first three of these were part of the FCC’s process in its Ligado decision, though critics of the outcome might question how rigorously each was applied:

• Hundreds of public comments were received before the order was issued.
  • Critics note that opposition to the FCC’s eventual course of action was expressed by stakeholders across a very a broad spectrum of society.
• The applicant, Ligado, was required to bear the burden of proof.
  • However, as the National Academies report says, different assumptions in Ligado’s analysis led it to an entirely different conclusion from studies done by the Department of Transportation.
• The FCC order allowing Ligado to operate includes “preventative actions.”
  • Yet many see these preventative measures as unworkable window dressing. In the staid and reserved phrasing of the National Academies report, they “may in some cases not be practicable within operationally relevant time and financial parameters.”

Regardless of the virtues or sins of its process to date, the FCC’s path forward must hinge on the final tenant of the precautionary principle: “Exploring a wide range of alternatives in the face of uncertainty.”

The most obvious, simplest, and straightforward of these alternatives is for the FCC to assign Ligado different frequencies, ones more distant from those used by space-based applications.

Admittedly, this path is only “simple and straightforward” in concept. It will require restarting the frequency allocation process nearly from the beginning, detailed analyses, complex negotiations, and difficult decisions.

Yet the current situation means certain harm to an unknown but significant number of GPS and Iridium users. Harm that could, in some instances, be severe. Even life-threatening.

It also means harm for Ligado. As things stand now, the company will always be under a cloud in the minds of federal officials and other GPS and Iridium users. Ligado will also undoubtedly be blamed for a variety of problems not of its doing from solar weather to criminal jamming. And a significant mishap related to company-caused interference could cause it extreme harm. Perhaps even bringing about Ligado’s demise.

The radio frequency spectrum is a limited and critical national resource. The FCC’s desire to use it to best advantage is necessary and appropriate. This, however, requires great care to safeguard the overall environment and existing users.

Resolving the “Ligado issue” will require creativity and a departure from the adversarial approach that has characterized the FCC process to date. Let’s hope that as the commission reconsiders the issue, it finds a way for everyone to come out ahead.

Dana A. Goward is president of the Resilient Navigation and Timing Foundation.

<p>The post Opinion: FCC must protect the environment and assign Ligado different frequencies first appeared on GPS World.</p>