Which time standard is employed for frequency hopping synchronization?

The correct answer is the combination of Julian date and GMT (Zulu) because frequency hopping synchronization relies on precise timing to ensure that transmitting and receiving units are operating on the same frequency hops at the same intervals. Julian date provides a continuous count of days since a specific starting point, which is particularly useful in military operations for tracking time across various time zones.

GMT, often referred to as Zulu time in military contexts, is a time standard that does not change with seasons, making it ideal for synchronization among units operating across different geographical locations. This uniformity minimizes the risk of confusion that may arise from time zone differences and daylight saving time changes. Using GMT in conjunction with the Julian date allows for a reliable, consistent method of synchronizing operations that utilize frequency hopping technology, necessary for secure and effective communications in a military environment.