Satellite technology has become a major part of our everyday lives. It has even brought the information age to America's family farms. Global Positioning Systems allow a person to accurately relocate a place on the Earth's surface, once the coordinates of the site have been recorded.
The NDSU Extension Service Publication, "GPS Applications in Crop Production" provides an excellent overview of how satellite technology can be used on the farm.
According to NDSU, "The GPS system uses measured distances to the precisely located GPS satellites to locate positions on the earth."
The importance of being able to receive a signal from more than one satellite was dealt with by launching 24 satellites in the GPS constellation, doing so allows a receiver to pick up a direct signal from at least four satellites at any given point on the earth's surface.
This technology has been adopted by agriculture because it allows for less waste. Broadcast applications of fertilizer that apply the same rate across the entire field have been used in the past because there wasn't an easier, better way to apply it. Global Positioning Systems technology is used in grain farming to map the parts of the field that have higher or lower yields, weed pressure, and soil fertility levels.
GPS is most commonly used on the farm for auto-steering guidance systems. The auto steering systems can be programmed to keep the tractor or sprayer exactly in the path it needs to be in dependant upon the width of equipment being used.
The sensors use GPS receivers to map exactly where the machine is located respective to its previous field path. This results in maximum fuel efficiency, fertilizer placement and minimum crop loss due to operator steering error.
GPS is also used in harvest operations typically in conjunction with the combine yield monitor. Combine location is mapped as it travels across the field and the field position is linked to the amount of grain being processed by the combine at that field location. The resulting data is then downloaded into geographic information system software.
Geographic information systems are, according to NDSU, "used to analyze and correlate information between GIS layers."
The layers being referred to here are data layers that can be shown on a field map. The satellite technology that launched the space race continues to bring new farm management techniques to the forefront. The use of GPS technology on the farm has led to an entire new science, known as precision agriculture, or site specific farming. The outcome of this technology has led to variable rate application. The GPS derived datasets allow producers and commercial applicators to apply crop inputs on a site specific system.