Observational calibration is a research area that focuses on the process of determining and adjusting the systematic errors in observational data collected from scientific instruments. This involves comparing the measurements taken by instruments to known standards or reference values in order to correct for any inaccuracies or biases in the data. Calibration is essential for ensuring the accuracy and reliability of observational data in various scientific fields, including environmental monitoring, astronomy, and medical research. By properly calibrating observational instruments, researchers can ensure that their data is precise and can be confidently used for analysis and interpretation.