Beginning May 16, life will easier for Alabama farmers who have adopted global positioning systems as part of precision agriculture.

That’s when the Alabama Cooperative Extension System and Auburn University’s Biosystems Engineering Department will dedicate a continuously operating reference station at R.A. Hubbard High School in Courtland.

The system joins a host of others that have been installed nationwide by other state or local entities.

The National Geodetic Survey coordinates CORS sites nationwide. The system provides positioning accuracies down to a few centimeters relative to the national spatial reference system. Without the correction, the GPS system may be accurate to within only a few feet.

For example, a tractor equipped with an Internet-accessible cellular modem could receive round-the-clock continuous correction data using a CORS.

“The nice thing about CORS is that NGS maintains data for these

sites, which are checked every 24 hours for accuracy,” says Shannon Norwood, a Selma-based Extension precision agriculture agent who also played a role securing funding for this station.

Without a CORS system, farmers who use GPS have had to purchase base stations for about $12,000 apiece. The base stations provide only a 6-mile coverage radius and require line-of-site transmission, which means users have had to move the bases periodically.

A key advantage of a CORS station is that it provides extended range with no line-of-sight requirements.

“We’re getting four to five times the range with the CORS station that we do with traditional base stations,” says Amy Winstead, a Belle Mina-based Extension precision farming agent who also was instrumental in securing funding for the technology.

At a cost of $25,000, the station not only is benefiting farmers, but also numerous other professionals who use GPS receivers as part of their work.

Both Winstead and Norwood say they believe the accuracy and convenience associated with CORS offers other advantages.

The enhanced accuracy ensures that farm equipment remains on the same track during each pass through the field--a factor that greatly reduces the recurrent problem of soil compaction.

CORS also may prove to be a major asset for farmers confronted with a weather calamity, such as an early spring freeze when they are forced to replant or an autumn hurricane when they must run their harvesters night and day to beat the storm.

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