GPS receivers may take Y2K-like hit ground signal failures

------------------------------------------------------------------------ By Jon E. Dougherty ) 1999 WorldNetDaily.com

The GPS -- or Global Positioning System -- 24-satellite array encircling the globe will not be affected by Y2K-related glitches, but some ground receivers that process the signals from these satellites may not function properly after Aug. 21, say government and military sources.

According to press releases and information published by the federal agencies and the military, the GPS system will "roll over from week 1,023 to week 0000 UTC or GMT," causing many ground receivers produced before 1994 to process signals incorrectly. The glitch could cause receivers to display inaccurate positions, times or dates, or may cause them to completely fail, according to the U.S. Information Agency (USIA).

"Officials said that reports appearing in a number of countries claiming that the system will cease to function at the time of the rollover are in error," the USIA said. "However, they urged GPS users with older receivers ... to check with manufacturers to assure that their equipment will correctly deal with the rollover.

The GPS system was designed to work on a cycle of 1,024 weeks, or about 20 years. The first cycle began Jan. 6, 1980 when the system was launched, and Aug. 21 marks the end of the cycle. It is the first rollover of the GPS system.

According to technical data, the problem stems from erasable programmable read-only memory chips installed in GPS receivers. Older chips may not be able to process the rollover changes and hence will have to be replaced, though in some cases, "it may be easier and cheaper to purchase a new receiver than to repair the

old," said the USIA. Widely used in military, commercial and civilian applications, GPS systems rely on a precise timing source (clock) to perform their calculations. This aspect of GPS receivers allows them to generate both relative and absolute time, according to a technical report released by the FCC.

"Fast digital networks use an external clock to enable synchronous data transmission," the report said. "For some data transmission systems, GPS based timing systems are used to provide the necessary timing information" -- a function that could cease to work properly if faulty data processing chips are not replaced.

Calculating exact locations via GPS takes place in three stages. The 24-satellite array, called the GPS Operational Constellation, transmits data to receivers located on earth. The second stage consists of the Control Segment, which is a worldwide system of ground stations used to process the information received from satellites. The third stage, or the User Segment, are the actual GPS receivers located on vehicles, as hand held portable equipment, or as stationary ground equipment.

Robert Cannon, a spokesman for the FCC, was vague when WorldNetDaily asked by e-mail if the problem with personal GPS receivers was likely to be addressed before the rollover date.

"Only the owners of equipment can assure its readiness and it is up to each individual owner to thoroughly prepare their systems," he replied, referring all other questions to the U.S. Coast Guard. "They seem to be leading the effort on GPS."

In fact, the latest USCG memo on GPS systems warns that "users of the Global Positioning System (GPS) should contact the manufacturers of their receivers before Aug. 19 to determine if their systems could malfunction beginning on that date due to conditions related to "End-of-Week" (EOW) rollover."

That release was Furthermore, the GPS Joint Program Office, which is managed by the USCG, confirmed that all military applications endemic to GPS were "unaffected by the Year 2000 (Y2K) and GPS End of Week (EOW) Rollover Issues."

However, a USCG report said, "Civil GPS users may need to verify that their receivers and applications will work properly through these events."

The report said in essence, the "rollover problem is really a problem that occurs every 20 years," suggesting that it was a problem unrelated to Y2K. The Coast Guard, nonetheless, has compiled a list of GPS receiver manufacturers so civilian users could inquire about potential problems and possible repairs.

In late July, the Air Force reportedly conducted Y2K compliance tests on one of the 24-satellite GPS constellation, but no one could be reached to verify if the tests were successful. A report on the proposed tests was published in mid-July, however, and said the Air Force had already successfully tested all Block II and Block IIA satellites. The units to be tested at the end of July were Block IIRs, but the report did not say how many of each type of satellite the U.S. has deployed.

To this end, the Department of Defense has also been involved in testing certain receivers and has plans to continue testing until the EOW date.

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Jon E. Dougherty is a contributing editor to WorldNetDaily.

Ray

-- Ray (ray@totacc.com), August 16, 1999

Answers

The software to calculate the GPS rollover in recievers has got to be one of the easiest programs to write.

Did you know that Magnetic north is not true north?

-- Cherri (sams@brigadoon.con), August 16, 1999.

I saw a patient last week (I do ob ultrasound, and yes, we have installed the Y2K upgrades to give the correct due date, costing US $50,000), whose husband owns an air taxi service in bush Alaska. For you lower 48'ers, there are two main roads in the entire state (Glenn Highway and Parks Highway), which are even paved. As the saying goes, if someone cut Alaska in half, Texas would be the third largest state.

I asked the patient's husband (who has 6 aircraft in his fleet) if his GPS's in his planes were compliant or needed upgrades. He said, "yes, I've heard about that problem. I guess I'll need to look into it". I gave him a copy of the Garmin printouts from their website which I downloaded during what probably was the two minutes their site was not jammed up around midnight Alaska time.

Yes, Cherri, we are quite aware of magnetic north here in the Great Land. Do _you_ know (without looking it up) if you live in an area of positive or negative declination, and what "red in the shed" means (you _do_ know how to use a compass and not need a GPS, right?

===================================================================

"Oh, yes, my Precious, we shall see." The Lord of the Rings, JRR Tolkein (BBC adaptation).

-- Nelson Isada (isada@alaska.net), August 16, 1999.

Yes, Cherri, we are quite aware of magnetic north here in the Great Land. Do _you_ know (without looking it up) if you live in an area of positive or negative declination, and what "red in the shed" means (you _do_ know how to use a compass and not need a GPS, right?

As a sailor, I'm curious about these navigation terms. I am guessing pos or neg declination is whether or not you have east or west variance (we're about 11 deg W var here), or is it whether or not the variance is increasing or decreasing (incr here). Mag north is in norther Canada, Baffin island if I'm not mistaken. I know there is a longitudinal like line where there is zero variance, is that the line of declination?

I have no idea what "red in the shed" is - although I am most curious.

- Jim

-- Jim (x@x.x), August 16, 1999.

[Fair Use: For Educational/Research Purposes Only]

http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=001DSb

http://www.flatoday.com/space/today/080999a.htm

Aug. 9, 1999

Global Positioning System calendar faces rollover

Air Force Materiel Command Year 2000 Program Office News Release

WRIGHT-PATTERSON AIR FORCE BASE, Ohio - Engineers working on the Year 2000 computer problem will be watching as the Global Positioning System experiences an end-of-week rollover Aug. 21.

The Y2K bug watchers will follow the transition from one 1,024-week cycle to another, because of similar potential consequences: possible receiver failure, malfunctions, and inaccurate time and location data -- an early taste of troubles that Y2K could generate as the positioning system's timekeeping cycle resets to a new cycle.

"We can't consider ourselves ready for contingencies, such as Y2K, if we don't test our ability to organize and effectively manage situations," said Capt. John Rankin, Air Force Materiel Command deputy Y2K program manager. "We don't anticipate any adverse mission impacts, but we have to be ready to respond regardless of our expectations."

GPS computes time and date values based on a 1,024-week cycle, instead of a 365-day year. Inaugurated Jan. 6, 1980, this unusual timekeeping system uses a 10-digit binary number to mark time. The cycle runs out of 10-digit numbers at midnight between August 21 and 22.

The 24 GPS satellites that orbit 12,000 miles above Earth are typically used for navigation; however, GPS also serves as a precise clock that feeds and synchronizes time for countless system applications throughout the world.

GPS generates a time stamp on its satellite transmissions ensuring the correct data from each satellite is used. The system uses composite readings from 230 atomic clocks around the globe to track absolute and relative time down to a nanosecond. With such extraordinary accuracy, GPS receivers are used in local and wide area networks, bank automated teller machine systems, public utilities, radar nets and cellular phone towers to synchronize transactions and transmissions.

The GPS Joint Program Office at the Space and Missile Center, Los Angeles Air Force Base, Calif., reports GPS satellites are unaffected by the EOW rollover and Y2K key dates in 1999 and 2000; however, GPS receivers and ground equipment can be affected, especially if they were procured by other than the GPS program office.

When other sources were used to acquire GPS receivers -- notably small, hand-held commercial receivers -- users should contact the manufacturers to determine EOW compliance.

To counter possible EOW problems, users should have contingency plans with suitable workarounds or recovery procedures. For a majority of problems that could be encountered, simply cycling the power of the receiver, clearing the memory and obtaining a new almanac should solve the problem. Users should contact manufacturers to learn about their specific receivers.

Part of the Y2K "dress rehearsal" will involve activation of headquarters and base battle staffs throughout the command. Activation will enable the command to exercise and test its recently published Y2K Consequence Management Plan.

The GPS rollover and other Y2K-related information are available for military readers at the Space & Missile Center located at http://www.laafb.af.mil/SMC/CZ/homepage/y2000/body.htm.

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-- Linkmeister (link@librarian.edu), August 16, 1999.

Jim:

Go to the Arctic Orienteering Website:

http://www.alaska.net/~oalaska/

Then find the link to Map and Compassvia Orienteering Links:

http://www.uio.no/~kjetikj/compass/lesson2.html

See the section beginning with "The mistake is again to let the compass needle point towards the south. The red part of the compass needle _must_ point at north in the compass housing, or you'll go in the opposite direction". Turning yourself without turning the compass housing (before or after you are geomagnetically aligned, depending on your preference) is putting the "red [part of the compass]" in the "shed [the compass housing]".

This weekend, my secretary was navigating on a wilderness Alaskan lake (Lake Louise), navigating in the dark (rain and fog), with a GPS that died (boat swamped, GPS plugged into lighter socket, and shorted). "The Force) (and frequent trips) got her and her husband to their cabin. If you are a sailor, I assume you have Basic Map and Compass skills.

I know there is a longitudinal like line where there is zero variance, is that the line of declination? Yes, zero declination.

I use "East is Least, West is best" http://www.uio.no/~kjetikj/compass/declinrhyme.html

-- Nelson Isada (isada@alaska.net), August 16, 1999.

Folks, we seem to have touched it but we didn't really hit it. Magnetic North is often a fair piece from "ALMOST EXACTLY" true North. It can be as much as 7-10 degrees off (Cleveburgh is, IRRC about 7 (deg) and 20' off, but I'd have to check a local topo to be reasonably sure.

Chuck

-- Chuck, a night driver (rienzoo@en.com), August 17, 1999.

Nelson,

You lucky you, living in the best country in the country :o)

I remember now about turning your body and not the compass.

And if I do not have a compass? Guess I will just have to look around at the moss growing.

-- Cherri (sams@brigadoon.com), August 17, 1999.