GPS and Crop Circles

Robert B. Daugherty, who is credited for the widespread adoption of
center-pivot irrigation systems, died last week.

Today, many center-pivot irrigation systems use one or more GPS
receivers to control position. Many also use GPS to control the swing
arm at the outer end that is used to water the four corners of a
square plot.

An obituary (others in New York Times, Washington Post, etc.):

http://www.omaha.com/article/20101124/NEWS01/101129868

Daugherty bought the rights to Frank Zybach's 1952 patent for the
system, then began manufacturing and further developing the system.

http://www.livinghistoryfarm.org/farminginthe50s/water_04.html

"An employee told him about Frank Zybach and the center pivot. . . .

In 1954, Daugherty bought the patent rights for the center pivot
irrigation system from Zybach and Trowbridge for the promise of five
percent of future royalties. But, the promising technology took a
while to take off. In 1955, Valley built only seven systems. Five
years later, they built 50.

. . . By 1970, there were over 2,000 center pivot systems in Nebraska
alone. And while the semi-arid regions of the Great Plains were the
biggest market for pivots, the company had begun to sell systems
around the world. . . . Today, Valmont sells about half of the center
pivot systems built around the world."

http://www.livinghistoryfarm.org/farminginthe50s/water_0501.html

"By 2002, there were an estimated 170,000 center pivot or 'lateral
move' systems (center pivots adapted to move in a line through a
field) in operation in the U.S. Those irrigation systems were watering
about 21 million acres of land.

Some estimates add another 88,000 center pivot or lateral move systems
operating in a dozen foreign countries. Saudi Arabia has 21,000
systems, South Africa has 15,000, Spain has 10,000 and Brazil has
8,500. "

GPS was added to the mix starting in the late 1990s.

http://www.spacedaily.com/news/gps-99p.html
August 24, 1999
"Valmont Irrigation has developed a GPS-based irrigation system that
brings a tele-robotic level of control to field irrigation using GPS
positioning data to achieve efficient and precise irrigation."

http://farmindustrynews.com/cornering-gps
May 1, 2000
"Prototypes of GPS-guided irrigators are achieving pinpoint
accuracy. . . . The technology is extremely accurate - within 4 to 6
in. of ground zero. However, it is unlikely that it will be cost-
effective in the near future, not with $2 corn. Unless we can provide
a product that can either add value or create enough savings for a
payback, it doesn't pay to introduce GPS technology to the market."

http://www.allbusiness.com/technology/technology-services/829032-1.html
September 1 2001
"Global Positioning Systems (GPS) guidance technology can now deliver
positioning accuracy for efficient precise irrigation. Valmont
Irrigation, of Valley, Neb., and Lindsay Manufacturing Co., of
Lindsay, Neb., have the technological capabilities with potential
applications for irrigation systems.

The technology is capable of consistent, track-ontrack accuracy with
pivots and linear machines, as well as with corner arms. With guidance
of steerable corner arms that can cover up to 14 percent more acres,
the need for a buried wire guidance system is eliminated. Other
applications include field mapping and water and chemigation.

GPS technology assures continual adjustment of speed and steering that
is critical for precise, full-field irrigation, according to Craig
Malsam, director of engineering, research and development at Valmont."


Some other comments on use of GPS in irrigation:

http://www.southplainsprecisionag.com/sppa/index.php?option=3Dcom_content&t=
ask=3Dview&id=3D24&Itemid=3D33

"SPPA approached Trimble about creating a GPS system that worked with
center pivot irrigation. Trimble didn=92t see the value until with Texas
Tech=92s help, SPPA sent Trimble a satellite image of the 5.7 million
acres of center pivot farm land on the South Plains. After that, SPPA
was instrumental in helping to create the center pivot GPS system for
Trimble in 2003. "


http://www.ars.usda.gov/sp2UserFiles/Place/36221500/cswq-0305-157334.pdf
2007
"The requirements for linear and pivot systems differ, but the trend
is toward differential GPS (global positioning system) devices.
Historically, shorter center pivots have used the pivot's built-in
resolver, but even for short pivots,
frequent calibration may be necessary, depending on the accuracy
required. For longer pivots, either the accumulated bend in the system
across multiple joints between spans, or simply the resolver error
magnified
at the end, can require end-tower determination. This can be done with
electronic compasses or a GPS unit on the outer end tower."


Zybach's 1952 patent for center-pivot irrigation:

http://www.freepatentsonline.com/2604359.pdf

Some Valmont patents employing GPS with irrigation systems:

http://www.freepatentsonline.com/6095439.pdf
Corner arm system with GPS, filed Dec 1998, issued Aug 2000

http://www.freepatentsonline.com/6254018.pdf
3 GPS receivers to maintain center pivot alignment, filed Dec 1999,
issued Jul 2001

On 10-11-28 21:10 , Ed M. wrote:




Let's just ignore their role in the depletion of the Ogallala Aquifer.



--
gmail originated posts filtered due to spam.