Normalized histogram of the vibration-induced displacement of the SAT1 rotor, perpendicular to the line connecting the two encoders, during different phases of the constant elevation scans, quantified as R_encϕ_i (Section 2.2.2). Top panel: peak-to-peak rotor displacement at the scan turnarounds. The measured vibration-induced displacement is larger when the boresight angle is nonzero. Top right panel: schematic diagram of the encoder head locations relative to the rotor at boresight angles of 0° and ±45°. The encoder heads and rotor are indicated by small circles and a large black circle, respectively. The displacement is larger in the azimuth (scan) direction regardless of the boresight angle. When the boresight angle is zero, ϕ_i is only sensitive to the displacement in the elevation direction, whereas at ±45°, ϕ_i is equally sensitive to displacements in both azimuth and elevation directions, resulting in larger measured displacements. Bottom panel: rms of vibration-induced displacement in constant scan speed regions.