On a vessel with two RADARs, one has a different range indication on a specific target than the other. How would you determine which RADAR is incorrect?

The correct choice involves checking the sweep and timing circuits of both indicators for correct readings. This is fundamental because radar systems rely on precise timing, as they measure the time it takes for a pulse of energy to travel to a target and back. If there is a discrepancy in range indication between the two RADARs, the issue might be due to one of the systems mis-timing its sweeps, which could result in inaccurate distance readings. By ensuring that both indicators are functioning properly with the correct timing and sweep characteristics, you can determine which RADAR is providing the accurate range to the target.

Other options, while they may seem relevant, do not directly address the fundamental operation of the RADAR systems. Triangulating a target using GPS and visual bearings introduces external factors that may not directly resolve the underlying issue with the RADAR readings. Checking antenna parallax may not apply in this situation, as parallax typically refers to the apparent displacement or difference in the perceived position of an object viewed along two different lines of sight. Finally, using the average of the two indications does not effectively diagnose which RADAR is incorrect, as it fails to account for the potential errors in both systems. This approach can also lead to compounded errors rather than identifying the accurate