Final answer:
To determine the accuracy of an attitude indicator, it's important to cross-reference it with other verified instruments or the natural horizon, and for more precision, calibrate it against GPS data, which is highly accurate due to precise satellite synchronization.
Step-by-step explanation:
Using the attitude indicator, its accuracy can be best determined by cross-referencing other reliable flight instruments. For stationary accuracy checks, the artificial horizon on the attitude indicator should align with a known true horizon. In flight, the accuracy of the attitude indicator is typically cross-checked against the gyroscope horizon, which can be visually confirmed against the natural horizon in clear weather conditions. For more precise validation, the instrument can be calibrated against the GPS, which has exceptional accuracy due to the synchronization of the atomic clocks on its network of satellites. A similar concept is used in navigation, where tools like the sextant measure fixed points in the sky to determine the observer's location. Measurement accuracy, whether it's the direction of a vector, fluid velocity in aircraft instruments, or geographical position using GPS, relies on precise reference frames and the proper functioning and calibration of the measuring instruments.
For example, GPS calculates position based on the very brief time delays of signals from satellites. Even minor discrepancies like those caused by relativistic effects can affect accuracy, underscoring the importance of precision timing and synchronization. Similarly, fluid velocity indicators common in aircraft, such as those shown in figure 12.7(b), are designed for accuracy by careful calibration against known standards.