Subelement C: Satellite Systems— Topic :
Question 30C2
Element 9 (GMDSS Maintainer)How can a LES/RCC (Rescue Coordination Centre) determine if an Inmarsat-C Distress Alert is a TEST transmission?
Explanation
Inmarsat-C Distress Alerts are digitally encoded messages that contain various data fields. To prevent false alarms and ensure efficient operation, a specific "flag" or indicator is embedded within the message structure to identify if the transmission is a test. This allows a Land Earth Station (LES) or Rescue Coordination Centre (RCC) to instantly recognize that it's not a real distress situation, avoiding the unnecessary deployment of rescue assets.
Option B is incorrect because the initial determination is built into the message itself, not reliant on manual verification *to identify* it as a test. Option C describes an acknowledgement *after* the alert is received, not the mechanism for distinguishing it as a test transmission. Option D is incorrect because the system is explicitly designed to differentiate between valid and test alerts to prevent confusion and wasted resources.
Related Questions
2A6 Which of the following controls is not found on a VHF-DSC transceiver?30C1 Which of the following conditions would prevent communications between an Inmarsat-C data port and external data terminal equipment (DTE)?30C3 What is the meaning of the “ACB” Inmarsat-C Non-Delivery Notification (NDN) failure code?30C4 What condition can indicate a communication failure between the second receiver (RX2) and the Antenna Control Unit (ACU) in an Inmarsat Fleet 77 terminal?30C5 Which of the following devices can cause interference to Fleet 77/55 systems?