Some of the people closest to the land will be the first
to benefit from a new global positioning technology developed
to make NASA satellites more efficient and cost-effective.

Farmers will soon get the chance to put the new system to the
test through a partnership between NASA’s Jet Propulsion
Laboratory, Pasadena, CA, and NavCom Technology Inc., a wholly
owned subsidiary of Deere & Company, Moline, IL.

Tractors will be equipped with receivers providing instant
location information, which is vital for precision farming.
The technology will allow farmers to navigate fields at night
and when visibility is poor. More importantly, with soil
sensors and other monitors, it will let them calculate and map
out precisely where their fields may need more water,
fertilizer or weed control, saving both time and money.

The system combines software developed by JPL and real-time
global positioning system (GPS) data from the NASA Global GPS
Network to produce corrections to the GPS orbits and clocks.
These corrections are broadcast to people using communication
satellites operated by NavCom, which has licensed the
Internet-based Global Differential GPS software from JPL’s
parent institution, the California Institute of Technology in
Pasadena, and plans to market the system this summer.

“NASA’s Earth Science Enterprise supports pioneering
exploration and discovery of our home planet, while providing
America and the world with practical societal benefits from
our research,” said Dr. Ghassem Asrar, Associate Administrator
for the Office of Earth Sciences, NASA Headquarters,
Washington, DC.

“Our agreement with NavCom will accelerate NASA’s ability to
develop, test and demonstrate the utility of global, real-
time, precise GPS positioning for scientific and public
applications,” said John LaBrecque, Manager, Solid Earth and
Natural Hazards Program, NASA’s Office of Earth Sciences.

While existing GPS data can be used to locate a position
within a few meters, the new Global Differential GPS system
provides an instantaneous position to within 10 centimeters (4
inches) horizontally and 20 centimeters (8 inches) vertically
anywhere on Earth. No other system provides the same
combination of accuracy and coverage.

In space, the new technology may enable improved performance
by NASA’s Earth-observing satellites. Since the satellites
will have precise information on their position, the
information may make onboard data processing more efficient
and reduce the time needed to transmit the data to the ground.
NASA also expects this new positioning technology to open the
possibility for new airborne exploration techniques through
more accurately controlled flights of airborne sensors.

“In the area of natural hazard monitoring, real-time data from
radar and ground networks of GPS receivers might provide the
ability to monitor volcanic activity precisely and in real
time, like the motion before, during and after major
earthquakes,” said Dr. Yoaz Bar-Sever, Task Manager of the
NASA global differential GPS demonstration at JPL.

The system’s ability to provide precise positioning
information in real time has a variety of potential commercial
applications in aviation, marine operations, land management,
transportation and agriculture.

The Commercial Technology Office at JPL is responsible for the
collaboration between JPL and NavCom, which will provide NASA
with a continuous, GPS differential-correction signal and also
will invest in improving the NASA GPS infrastructure. This
collaboration is just one of several JPL programs designed to
bring the benefits of the space program to American industry.

NASA’s Earth Science Enterprise, Washington, DC, funds the
development of the Global Differential GPS system. The
Enterprise is a long-term research effort dedicated to
understanding how human-induced and natural changes affect our
global environment.