What equipment aids in determining the accurate range of maritime targets?

Rangefinders are specialized devices that measure the distance to a target, which is crucial for engaging maritime threats or conducting naval operations. They operate on principles such as laser measurement or triangulation, allowing operators to determine the exact range to both surface and aerial targets with high precision. This capability is essential for targeting systems that require accurate distance information to calculate weapon engagement parameters, thereby enhancing effectiveness in combat scenarios.

The correct answer underscores the importance of range measurement in naval warfare, where knowing the precise distance to a target can significantly impact mission success. While GPS units provide location and navigation information, they do not directly measure distances to targets. Radar altimeters are primarily used to measure altitude above the ground or water, and sonar systems typically operate underwater to detect objects and measure depth rather than range to surface targets. Each of the other options has its own purposes but does not specifically focus on directly determining the range to maritime targets in the way that rangefinders do.