What tool is used to predict ROD with a (V)4 SONAR?

The correct answer is HF-STDA. This tool is specifically designed to assist in predicting Range of Detection (ROD) with a (V)4 SONAR system. HF-STDA utilizes data and algorithms that factor in various environmental conditions and sonar system characteristics, providing operators with estimates on how effectively the sonar can detect objects at various ranges.

On the other hand, the other options do not serve the same purpose with respect to ROD prediction. VDS-Guide is primarily intended for guiding and managing variable depth sonar systems rather than predicting detection ranges. SonarMap focuses on visualizing data gathered by sonar systems, providing geographical representations of acoustic data rather than predictive capabilities. DepthPredictor, while useful for estimating underwater depths, does not specifically deal with sonar range detection metrics or performance predictions, making HF-STDA the most appropriate choice for this particular scenario.