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Technologies: AutoFarm SatVU

The accuracy of all our AutoFarm products, especially AutoLevel, is dependent on the quality and quantity of GPS signals received. Like the web-based SkyPlot, SatVU is a tool for predicting the GPS sensor performance throughout the day. Unlike Skyplot, SatVU runs on our AutoFarm cab box in the field.

Due to the motion of the GPS satellites in the sky, the number of visible satellites varies hour-to-hour within the day. SatVU produces a graph showing the number of visible satellites and the vertical dilution of precision (VDOP)during a 24 hour period. The values predicted by SatVU are ideal - any obstructions blocking the view of the sky (buildings, trees, etc.) will reduce the actual number visible.

In general, the more satellites visible, the better the GPS accuracy (10 or more satellites is very good, 4 or less is marginal for precision leveling). Although less intuitive, VDOP is a much better measure of performance than the number of satellites. A VDOP of 1 to 1.5 is very good while VDOP greater than 3 is marginal.

Below is an example of the display that an operator would see on the monitor in the tractor.