FREE GMDSS Navigation and Communication Questions and Answers
Equipment for radiotelephony use in survival craft stations under GMDSS must have what capability?
Explanation:
Equipment for radiotelephony use in survival craft stations under GMDSS (Global Maritime Distress and Safety System) must have the capability to operate on Channel 16. Channel 16 is the international distress and calling frequency designated for maritime communication. It is monitored continuously by maritime authorities and other vessels to coordinate distress, safety, and emergency communications. Therefore, operation on Channel 16 is a crucial requirement for survival craft stations to ensure effective communication during distress situations.
If the vessel is beyond the range of NAVTEX broadcasts and the Sat-C system fails, the GMDSS operator must:
Explanation:
When the vessel is beyond the range of NAVTEX broadcasts and the Sat-C system fails, the GMDSS operator can rely on High-Frequency (HF) MSI (Maritime Safety Information) broadcasts. In this situation, the operator should select an HF MSI frequency and set up the transceiver in FEC (Forward Error Correction) telex mode to receive MSI. FEC telex mode helps to ensure reliable data transmission over HF radio links, even in challenging conditions or over long distances. Therefore, selecting an HF MSI frequency and FEC telex mode is the appropriate action for receiving MSI when NAVTEX and the Sat-C system are unavailable.
Equipment for radiotelephony use in survival craft stations under GMDSS must have what characteristic(s)?
Explanation:
Equipment for radiotelephony use in survival craft stations under GMDSS must have several characteristics to ensure effective communication during distress situations. These characteristics typically include the ability to operate on Channel 16 (the international distress and calling frequency), having a permanently fixed antenna for reliable transmission, and being watertight to withstand harsh maritime conditions. Therefore, all the characteristics listed must be met by equipment used in survival craft stations under GMDSS regulations.
To set up the MF/HF Transceiver for a voice call to a coast station, the operator must:
Explanation:
To set up the MF/HF Transceiver for a voice call to a coast station, the operator must select J3E mode. J3E mode is the appropriate mode for voice communications in the High-Frequency (HF) band. It is commonly used for transmitting voice signals over long distances with good audio quality and efficiency. Therefore, selecting J3E mode ensures proper voice operations during the call.
Which is the key part of the search and rescue system under GMDSS?
Explanation:
COSPAS/SARSAT (Cosmicheskaya Sistyema Poiska Avariynich Sudov/Search and Rescue Satellite-Aided Tracking) satellites are the key component of the search and rescue system under GMDSS. These satellites are part of an international satellite system designed to detect and locate distress signals from emergency beacons (EPIRBs, ELTs, and PLBs) transmitted by ships, aircraft, and individuals in distress. When a distress signal is received, COSPAS/SARSAT satellites relay the signal to ground stations, which then coordinate search and rescue efforts to assist the distressed party. Therefore, COSPAS/SARSAT satellites play a crucial role in saving lives at sea and in remote areas around the world.
Selective FEC communications (SFEC) are employed when:
Explanation:
SFEC is utilized when a station needs to receive communications while refraining from transmitting, such as during radio silence periods. SFEC allows the station to receive messages reliably without the need for its transmitter to be active. This is particularly important in situations where maintaining radio silence is crucial, such as during certain military operations or emergency scenarios.
How are paired NBDP frequencies normally used?
Explanation:
Paired NBDP (Narrow-Band Direct Printing) frequencies are typically used for ARQ (Automatic Repeat reQuest) communications with coast radio stations. ARQ is a data transmission protocol used to ensure the reliable delivery of messages over a radio link. In ARQ communications, data packets are sent from one station to another, and the receiving station acknowledges the receipt of each packet. If a packet is not received correctly, it is automatically retransmitted until it is successfully received. Therefore, paired NBDP frequencies are used for ARQ communications to facilitate reliable data exchange between ships and coast radio stations.
If the vessel is experiencing atmospheric interference with NAVTEX broadcasts, especially in the tropics, the GMDSS operator should:
Explanation:
In areas experiencing atmospheric interference with NAVTEX broadcasts, especially in the tropics, the GMDSS operator should select one of the 8 HF (High-Frequency) MSI (Maritime Safety Information) frequencies and set up the transceiver in FEC (Forward Error Correction) telex mode. FEC is a method used to detect and correct errors in transmitted data without the need for retransmission, which is beneficial in environments where atmospheric interference may corrupt the received signal. By using FEC telex mode on the HF MSI frequencies, the operator can improve the reliability of receiving NAVTEX broadcasts despite atmospheric interference.
FEC NBDP transmissions are normally used to?
Explanation:
FEC NBDP transmissions are indeed used to receive HF MSI (High-Frequency Maritime Safety Information) and NAVTEX (Navigational Telex) broadcasts. These transmissions are vital for receiving important safety-related information such as navigational warnings, weather forecasts, and other maritime safety messages.
Which statement is NOT true regarding the COSPAS-SARSAT system?
Explanation:
The COSPAS-SARSAT system is primarily designed for search and rescue operations, specifically to locate and assist distressed vessels, aircraft, and individuals. While it utilizes Doppler shift to locate distress beacons transmitting on 406 MHz and EPIRBs are used as satellite beacons aboard lifeboats as alerting devices, it is not intended for transmitting public correspondence. The system's main function is to detect and relay distress signals to search and rescue authorities for prompt action, rather than facilitating general communication. Therefore, the statement that COSPAS-SARSAT may be used to transmit public correspondence is not true.
Which would indicate proper operation of an SSB transmitter rated at 60-watt PEP output in J3E mode?
Explanation:
In Single Sideband (SSB) voice mode (J3E), the transmitter should not produce any power output when keyed but without speaking into the microphone. This is because SSB transmitters are designed to only transmit audio frequencies, and if there is no audio input (i.e., no speaking into the microphone), there should be no power output. This behavior indicates proper operation of the SSB transmitter, ensuring that it does not transmit unintended signals or interference when not in use.