On Fri, 23 Dec 2011 08:14:49 -0500, JustWait
wrote:


One can get accuracy to 3 ft, and even to 6 inches. Just have to throw
money at it.

Just with GPS? I was told the closest they could "tune" the atomic
clocks in the sattelites created a sloppy area. "That's why they can't
land a jet on an Aircraft Carrier with GPS alone, it can't account for
the pitch of the deck"...

The pitch of the deck has to do with altitude above sea level. GPS is
notoriouly very inaccurate on that.

Dang it, I forget the term, DPGS? Anyway you can set up your own
stations around the field to increase accuracy. I know you could buy
those units, but this was a while back. I hate to assume, but I assume
they're still available.




Years ago, before GPS, my company did a custom radio control for a
local cane farmer's tractor, with all the necessary failsafes. He
would drive the harvester and the R/C tractor with a fifth wheel
trailer alongside. When the trailer was full, he'd drive the tractor
to the pickup site, disconnect and hook on an empty and continue.

Was this GPS alone, something else, or a combination??

Uh, look at the first sentence, "Years ago, before GPS,...". It was
strictly radio control. We set up a custom panel in the harvester with
a couple joysticks and a few switches.

Rick

On 12/23/2011 10:03 AM, Rick Morel wrote:
On Fri, 23 Dec 2011 08:14:49 -0500, JustWait
wrote:


One can get accuracy to 3 ft, and even to 6 inches. Just have to throw
money at it.

Just with GPS? I was told the closest they could "tune" the atomic
clocks in the sattelites created a sloppy area. "That's why they can't
land a jet on an Aircraft Carrier with GPS alone, it can't account for
the pitch of the deck"...

The pitch of the deck has to do with altitude above sea level. GPS is
notoriouly very inaccurate on that.

Dang it, I forget the term, DPGS? Anyway you can set up your own
stations around the field to increase accuracy. I know you could buy
those units, but this was a while back. I hate to assume, but I assume
they're still available.




Years ago, before GPS, my company did a custom radio control for a
local cane farmer's tractor, with all the necessary failsafes. He
would drive the harvester and the R/C tractor with a fifth wheel
trailer alongside. When the trailer was full, he'd drive the tractor
to the pickup site, disconnect and hook on an empty and continue.

Was this GPS alone, something else, or a combination??

Uh, look at the first sentence, "Years ago, before GPS,...". It was
strictly radio control. We set up a custom panel in the harvester with
a couple joysticks and a few switches.

Rick

Interesting, thanks.

"WaIIy" wrote in message
...
On Fri, 16 Dec 2011 11:21:03 -0500, "Wilbur Hubbard"
wrote:

"Wayne.B" wrote in message
. ..
BusinessWeek is carrying an article today that says that government
tests showed that the proposed LightSquared mobile service caused
interference to 75% of all GPS receivers tested.

The report can be found at: http://preview.tinyurl.com/7jyaazf

There is big money behind this. I'd recommend writing your elected
representatives and voicing your concerns.




It seems to me real sailors needn't be concerned about this at all.
Who
needs GPS inland or very near coastal anyway where landmarks and
navigation marks are eyeball visible? Those who proceed down the
Intracoastal Waterway with eyes glued to their GPS readout are putzes
to
be sure.

It's obvious you haven't sailed at night.



Nighttime is for anchoring or docking when one is recreational sailing
inland waterways. And, even if one likes to take unnecessary chances
recreational sailing or even if one sails for a living commercially,
since the interference is only within 100 meters of a transmission
station, it will result in a GPS not being accurate for all of about
five seconds (your sample rate is probably not much greater this this)
when you're underway should you happen across such a station right in
the middle of the channel.

The concern about vessel navigation being compromised by this is a
laughable one.


Wilbur Hubbard

On 12/23/2011 6:46 PM, WaIIy wrote:
On Fri, 23 Dec 2011 12:30:38 -0500, "Wilbur Hubbard"
wrote:

wrote in message
...
On Fri, 16 Dec 2011 11:21:03 -0500, "Wilbur Hubbard"
wrote:

wrote in message
...
BusinessWeek is carrying an article today that says that government
tests showed that the proposed LightSquared mobile service caused
interference to 75% of all GPS receivers tested.

The report can be found at: http://preview.tinyurl.com/7jyaazf

There is big money behind this. I'd recommend writing your elected
representatives and voicing your concerns.




It seems to me real sailors needn't be concerned about this at all.
Who
needs GPS inland or very near coastal anyway where landmarks and
navigation marks are eyeball visible? Those who proceed down the
Intracoastal Waterway with eyes glued to their GPS readout are putzes
to
be sure.

It's obvious you haven't sailed at night.



Nighttime is for anchoring or docking when one is recreational sailing
inland waterways. And, even if one likes to take unnecessary chances
recreational sailing or even if one sails for a living commercially,
since the interference is only within 100 meters of a transmission
station, it will result in a GPS not being accurate for all of about
five seconds (your sample rate is probably not much greater this this)
when you're underway should you happen across such a station right in
the middle of the channel.

The concern about vessel navigation being compromised by this is a
laughable one.


Wilbur Hubbard



You said "Who needs GPS inland or very near coastal anyway where
landmarks andnavigation marks are eyeball visible?"

Like I said - It's obvious you have never sailed near coastal at night.
I've been trying to reason what gives with this corporate greed. No
doubt once they own the bandwidth they will seek to license access to
GPS frequencies they control or interfere with.
This stuff of Global Corporate Monopoly/government needs to be brought
to a screeching halt. Any conversation with our elected people, in
Washington just runs into gibberish, diversion and defense of the new
reality of Global economy, governance and supplier side rule.