Satellites orbiting far above the earth are helping fight weeds in eastern Iowa. The Clinton County Conservation Board is the first in the state to begin using global positioning satellites — or G-P-S — to keep track of its weed-killing efforts.Walt Wickham is deputy director of the board. He says the use of G-P-S will enable the board to track when it applied what weed killers where and how much was sprayed on the many miles of ditches in the county. He says the new calculations are accurate to within three feet.Wickham says all of the data from the new G-P-S system is computerized and color-coded, making it very easy to monitor progress in whacking weeds countywide. He says the board oversees about one thousand miles of roads in Clinton County, which equates to two thousand miles of ditches.The Clinton board was chosen along with the Washington State Department of Natural Resources to test out the weed-spray tracking system by a high-tech company in Illinois.