What should be done first when verifying normal system indications for ATIS?

When verifying normal system indications for the Automated Terminal Information Service (ATIS), identifying the ATIS locations is the most logical first step. This involves confirming the specific airports or airfields that the ATIS broadcasts cover. By establishing the locations, it ensures that the appropriate information for the right area is being monitored and verified.

This step is essential because if the wrong locations are referenced, any further checks or tests conducted may not yield relevant results. It sets a foundation for effective communication and understanding of the data being received. Having clarity on ATIS locations allows for efficient verification of subsequent elements of the ATIS system, such as frequency testing and hardware inspections, to ensure overall accuracy and functionality.

The other options, while related to the verification process, would typically follow after confirming the correct ATIS locations. For example, testing the ATIS frequency or inspecting the VIDS hardware would have less value without first ensuring the right location context.