Measuring the panels with photogrammetry: . ... Back fit for camera position and determine position of each target (no distance scale, only angles). ... Adjusting the panels: . North/south support cables have tieback cables that can be adjusted to pull the cable catenary close to the spherical shape. ... Results: . Rms of primary less than 1.6 mm over the beam area. plots showing results of the second round of target measurements (there was one more adjusting round after this). next previous ...