How is HAARP involved in this conspiracy, it must be!
73s and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Technical Specialist
ARRL Volunteer Examiner
ARRL OOC for Oregon
On 4/3/19 12:30 PM, Fred Jensen wrote:
The week number register is in the hardware aboard the GPS satellites,
although receivers usually read and store it too. Each rollover is a
"GPS epoch," epoch being a term used by space travelers, astronomers,
and other folk dabbling in space-ish things to confuse the rest of us.
The first epoch ended in Aug 1999 ... 1024 weeks is 19.<mumble> years.
We are approaching the end of epoch 2. In 1999, a few of the early GPS
receivers hit the WNRO [week number roll over] and thought it had become
1980 again. Using a GPS receiver to discipline the K3 involves the
clock signal and unless you are using your very very old receiver to
tell you what the current date is, the WNRO will have no effect.
Early in the first GPS epoch, it was discovered that the "civilian"
signal was yielding somewhat better accuracy than the US Dept. of
Defense had planned, and they implemented SA or Selective Availability
to perturb the satellite clocks making it appear that you were moving
around randomly in a 100-200 m area when you were in fact stationary.
This would affect the clock signal at the receivers and thus the
"discipline" applied to the K3.
It wasn't very long before a number of entities, including manufacturers
and the US Coast Guard ... found ways to get around SA. One is
Differential GPS which places stations at very carefully surveyed
locations, monitors their GPS reported positions, and transmits the
errors. The DGPS receiver uses the errors to correct its own GPS
position. If you have the new synthesizer for your K3 [or a K3s], you
can hear and decode the DGPS signals, they're 100 bps MSK in the 284-458
KHz range and have a distinctive signature on a P3. The US DoD gave up
on SA long ago but the DGPS stations remain, or at least did the last
time I checked.
One GPS conspiracy theory posited that there was a "back door" into the
satellites put there by another country [which we'll leave nameless]
which, when activated, would be used to cause all the aircraft in the
air to converge on one point and create a great conflagration.
Conspiracy theories have a half-life and fortunately this one was fairly
short, similar to the half-life of disco and leisure suits. [:-)
73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County
On 4/3/2019 11:24 AM, n...@zianet.com wrote:
Fred Jensen writes:
Eventually, the 10-bit register holding the week number will overflow
and reset to zero. That's all that's happening, it happens every
1,024 weeks, the first was in Aug 1999.
The GPS reset has been the source of hysteria in various circles,
including exhaustive discussions on the various private pilot and
drone forums, since most aircraft and drones use GPS for real time
positioning and navigation while in flight.
In short, when this happened in 1999, changes were made to lengthen
the roll over period to beyond our lifetime. The April 6 rollover
only effects older GPS devices with the 10-bit registers. Basically,
every GPS embedded device made in the last 10-15 years or so will not
be affected - only the first generation devices.
There are absolutely no warnings or cautions on the websites for
Garmin, Magellan, or Trimble showing it is a non-issue for their GPS
devices - not even mentioned. The FAA has a list of the very few GPS
devices used in older private aircraft that could be effected, only if
in flight when the rollover occurs. With 10,000+ people in the air at
any moment, there would be a huge air of caution by the FAA and
airlines if the rollover had any chance of effecting the GPS devices
now in use. In this case, "Silence is golden."
73, Paul NA5N
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