Basic Description: Detrend removes the trend or slope in data, usually caused by instrument drift but also by changing ground conditions across a survey. The trend or slope is removed by fitting a line or curve across the tile and then subtracting it from the tile. Note also that using the trend option in the Match Operation allows you to remove a trend in one tile by matching the edge to the selected neighboring tile.
Technical Details: Detrend removes broad trends in tiles that occur either along individual traverses or across traverses, using a linear, quadratic, or cubic best fit. When along traverse is chosen, the trend in each traverse is corrected. When across traverse is selected, the trend in the entire tile is corrected.
Instructions: After choosing a selection method and making your selection on the survey, enter parameters in the following order (go to each section for details):
 Direction
Choose along traverse to run the algorithm along each transect from start to end (in the order transects were collected).
Choose across traverse to run the algorithm in the direction perpendicular to survey direction.
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 Method
The linear method makes a plane of best fit using a first order polynomial.
The quadratic method uses a second order polynomial.
The cubic method uses a third order polynomial.
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