Residual Display

You can view a visual representation of residual errors by superimposing vectors of the collected points and residual errors over the image. Observing the patterns in the vectors can help you identify possible causes and solutions for any such errors.

To set up residual display

Click the Point Residuals list, and then select the axis or axes for which you want to display the point residuals:
- X,Y: displays the x-axis and y-axis residual errors as separate vectors for each point.
- XY: displays the residual errors for each point as one vector representing the combined x-axis and y-axis residual errors.
- Z: (for stereo ground control points (GCP) and check points (CP) only) displays the residual error for the elevation of each point as one vector along the y-axis.
For each item under Residuals:
- Under Magnify, type a value in each box to indicate the magnification of the display for GCPs, Check Points, and Tie Points.
  The magnification factor exaggerates the appearance of the residual error, making it easier to observe systematic patterns. For example, with a value of 5, the residual error displays as five pixels long in the viewer.
- Under Color, click to select the color you want to use for the residual in the display.
In the Highlight residuals greater than box, type or select a value to have residuals greater than the value appear highlighted in the display, and then from the list to the right, select an appropriate unit for the value: Ground, Pixels, or Microns.