Shift Track

Shift Track controls work as described in the GENERAL GUIDANCE section.

Shift Track is used to shift the tracks radially closer or further from the center point. Shift Track does not move the center point itself. This method of Shift Track allows the operator to use various implement widths, account for different lengths of center pivot towers or to account for stretching/shrinking of the center pivot irrigation sections.

When using SF2 or SF1 Differential Correction (or when using RTK Quick Survey Mode) the Circle Center may drift over time or at power cycles. In Circles Track Mode, Shift Track does not compensate for GPS drift. In order to achieve accuracy and repeatability when using SF1 or SF2 Differential Correction, the center point must be recalculated by manually driving the circle on a daily basis (see Calculating Circle Center).

RTK Absolute Base Mode is highly recommended in high accuracy applications when using Circle Track. Only RTK Absolute Base Mode provides consistent repeatability and accuracy in Circle Track.

Example 1 - Operator makes first pass through the field saving Circle Center information to EAST FIELD (Field Name) and CENTER1 (Track Name), pulling a 4.6 m (15 ft) implement. The operator returns for second pass in same field with 9.1 m (30 ft) implement. To follow the same track stored, recall EAST FIELD and CENTER1, line up on desired track and SHIFT CENTER to allow for the difference in implement widths.

Example 2 - Operator is using SF2 and defines a circle center point by manually driving the circle. The following day, the operator returns to the field and finds that the AutoTrac is not lining up properly with the previous day’s path due to GPS drift. The operator must re-drive the circle to find the Circle Center Point.