What is necessary for a Link 16 terminal to obtain coarse synchronization?

The correct option is the reception of one error-free J0.0 Initial Entry Message (IEM). This message is essential for a Link 16 terminal to achieve coarse synchronization within a network. The IEM serves as the primary synchronization reference, providing the terminal with critical timing information necessary to align with other units in the Link 16 network.

When a terminal receives this initial entry message, it can accurately determine its time setting, which is crucial for effective communication and data exchange with other network members. Coarse synchronization allows terminals to get an overall timing reference, making it possible for subsequent precise synchronization processes to occur as more data is exchanged across the network.

In contrast, while the reception of three error-free PPLI messages or continuous network time signals might contribute to maintaining synchronization, they do not serve as the initial requirement for coarse synchronization like the J0.0 IEM does. Similarly, the reception of multiple synchronization requests might aid in achieving additional synchronization levels, but it is not necessary for the initial coarse synchronization. Understanding the foundational role of the J0.0 IEM emphasizes its importance in establishing reliable communication among Joint MTN Operations.