What technique is used to automate the initial call between two marine stations?

Digital Selective Calling (DSC) is the correct technique used to automate the initial call between two marine stations. This automated system enhances communication at sea by allowing maritime operators to send distress and routine messages without requiring voice communication. DSC operates within the Global Maritime Distress and Safety System (GMDSS) framework, which helps ensure that vessels can quickly and effectively connect with each other or with shore stations.

The technology leverages digital signals to send information such as the identity of the calling station and the type of call (e.g., distress, urgency, or routine). By using DSC, mariners can initiate communications more efficiently, which is particularly crucial in emergency situations where time is of the essence.

Other methods like Frequency Modulation (FM) and Amplitude Modulation (AM) are analog techniques primarily used for traditional broadcasting communications but do not offer the automation and specificity required for marine communications. Satellite Communication (SatCom) broadens the scope of maritime communication but does not specifically automate initial calls like DSC does. Therefore, DSC stands out as the specific solution designed for this purpose in maritime operations.