1. Where do comparison errors come from?
In traditional manual inspection, shooting position, angle and distance are not fixed each time; the same defect appears differently in photos from different periods, distorting dimension measurement and trend judgment — the main source of multi-period comparison errors.
2. How is same-source comparability ensured?
RIEJIAN relies on intelligent reusable routes + a digital twin base; each inspection’s flight trajectory, shooting viewpoint and collection parameters are fully unified: the same route, same position and same angle are used for collection, ensuring same-source, valid year-on-year multi-period data.
3. Reliability of trend analysis
With same-source data, the system automatically matches member points and the same defect, precisely presenting cross-period evolution of size and count trends; comparison results are authentic and valid, providing a reliable basis for maintenance decisions.
4. Applicable conditions and scenarios
- Continuous comparison of annual periodic inspection and regular re-inspection
- Trend tracking of key defects
- Evaluation of defect maintenance effectiveness
5. Notes
Comparison analysis depends on unified route execution; if bridge structural modifications cause route changes, a new comparison baseline should be established accordingly.