When starting with a grid coordinate target, what is the first procedure the FDC performs to prepare gun data?

When starting with a grid coordinate target, what is the first procedure the FDC performs to prepare gun data?

• A. Determine azimuth to the target.
• B. Convert grid to a relative position.
• C. Issue firing orders immediately.
• D. Calculate time of flight.

Answer: (B)

Converting the grid coordinate target into a relative position with respect to the firing unit is the first step because all gun data calculations start from the same reference frame—the battery’s own location. By turning the grid target into offsets north/south and east/west from the guns, the FDC can immediately determine the target’s location in a way that matches the gun’s perspective. This establishes the basis for deriving azimuth and range, and then feeding accurate data into ballistic computations and time-of-flight, with wind and other corrections tied to that same reference. If you skip this step, you’d be trying to work from map coordinates without a consistent origin, which makes the subsequent calculations unreliable. After establishing the relative position, the FDC proceeds to determine direction and distance, then calculate time of flight and prepare the firing data for the guns.

Converting the grid coordinate target into a relative position with respect to the firing unit is the first step because all gun data calculations start from the same reference frame—the battery’s own location. By turning the grid target into offsets north/south and east/west from the guns, the FDC can immediately determine the target’s location in a way that matches the gun’s perspective. This establishes the basis for deriving azimuth and range, and then feeding accurate data into ballistic computations and time-of-flight, with wind and other corrections tied to that same reference. If you skip this step, you’d be trying to work from map coordinates without a consistent origin, which makes the subsequent calculations unreliable. After establishing the relative position, the FDC proceeds to determine direction and distance, then calculate time of flight and prepare the firing data for the guns.