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Staying Connected
With every GPS tool, the user is at the mercy of the available satellite signals. When those signals get dropped, the equipment must make adjustments to the data — in some cases, with disastrous results.

Ellis Astin's John Sorrell recalls one topographic survey project using a different GPS product. "It was a simple topographic survey of a relatively flat field. I lost the signal from the GPS about halfway through the survey, so I paused and waited for it to return. It did and I moved on," he notes. "During post-processing, I noticed there was a big valley that appeared in the middle of the field. I knew that wasn't right." It turns out the GPS tool had picked up the wrong signal in the middle of the field.

The Leica GPS900, on the other hand, is equipped with SmartCheck, which performs two independent checks — one every four seconds — on the GPS signal. "Our GPS900 ensures we don't have that mistake again," Sorrell states.