Issue link: https://geospatial.trimble.com/en/resources/i/1468600
Inside the Trimble X7: Deep Dive into Trimble X7 Auto-Calibration 4 4 Internal Collimator For the first time in an optical instrument, the integration of an internal collimator inside the instrument base enables the calibration process to be totally automated. No targets or user interaction is required to measure the primary axis errors. Figure 2: Internal Collimator for Trimble X7 The laser beam emitted by the scanner head can be measured over a full radius using the internal collimator camera, while the alidade drive system turns the center unit to different positions. The process of measuring a singular line of sight horizontal and vertical collimation error from a total station is extended to include infinite line of sight measurements taken over a 360° dome. This is done using X-Drive's combination of two vertical drive systems, the one placed in the alidade and the deflection unit for scanning. This auto-calibration procedure comes with multiple advantages. The first being that because the technology for the alidade's encoder system is adopted from total stations, the precision is already down to less than 3" (arc seconds) and provides confidence that the scanner head will be properly calibrated at each individual deflection unit encoder position for both horizontal and vertical collimation error. The procedure also accounts for all remaining alignment deviations inside the scanner as well as deflection unit encoder errors and rotational speed impacts. For example, in the case that the EDM beam and the deflection unit rotation axes are not identical, the scanning plane will not be perfect, but rather slightly bent.