On Thu, 22 Dec 2011 20:43:43 -0500, JustWait
wrote:

On 12/22/2011 8:09 PM, Wayne.B wrote:
On Thu, 22 Dec 2011 18:46:22 -0500, JustWait
wrote:

On 12/22/2011 6:11 PM, Wayne.B wrote:
On Thu, 22 Dec 2011 16:18:38 -0000, "Alisdair Gurney"
wrote:

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?

.. sorry, but I have to agree with this view.

======

Not really. A lot of navigation is done in coastal waterways and
inland rivers, some of it at night or in reduced visibility.

It turns out that one of the best connected opponents to the proposed
Lightspeed service is tractor manufacturer, John Deere. Apparently a
lot of new farm tractors are equipped with precision GPS units for the
purpose of accurate seed planting and other hi tech applications.


Been going on for a long time. GPS grids are running tractors, plowing,
planting, and working millions of acres with no drivers...

===

Holy cannoli ! Robotic tractors? Hope none of them have been
drinking and plowing a wide furrow. :-)


Well, I think they must use something to aid the GPS because iirc the
tolerance of GPS is +/- 30 feet or something like that...


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

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.

He was able to stack 'um up for the trucks to pick up all by himself.

Rick

On 12/23/2011 8:09 AM, Rick Morel wrote:
On Thu, 22 Dec 2011 20:43:43 -0500, JustWait
wrote:

On 12/22/2011 8:09 PM, Wayne.B wrote:
On Thu, 22 Dec 2011 18:46:22 -0500, JustWait
wrote:

On 12/22/2011 6:11 PM, Wayne.B wrote:
On Thu, 22 Dec 2011 16:18:38 -0000, "Alisdair Gurney"
wrote:

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?

.. sorry, but I have to agree with this view.

======

Not really. A lot of navigation is done in coastal waterways and
inland rivers, some of it at night or in reduced visibility.

It turns out that one of the best connected opponents to the proposed
Lightspeed service is tractor manufacturer, John Deere. Apparently a
lot of new farm tractors are equipped with precision GPS units for the
purpose of accurate seed planting and other hi tech applications.


Been going on for a long time. GPS grids are running tractors, plowing,
planting, and working millions of acres with no drivers...

===

Holy cannoli ! Robotic tractors? Hope none of them have been
drinking and plowing a wide furrow. :-)


Well, I think they must use something to aid the GPS because iirc the
tolerance of GPS is +/- 30 feet or something like that...


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"...

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??

He was able to stack 'um up for the trucks to pick up all by himself.



Rick

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.