Tổng quan hệ thống GMDSS phục vụ TKCN. Năm 1979,Tổ chức Hàng Hải quốc tế (International Maritime Organization IMO) đã tổ chức hội nghị về vấn đề tìm kiếm và cứu nạn trên biển. ... Hệ thống mới được tự động hóa và sử dụng sóng vô tuyến trái đất và vệ tinh cho báo động cấp cứu và các thông tin theo sa
Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B Simplex operation is where one frequency is used for a paired frequency ITU Channel alternate transmission and reception the up and down link on an Inmarsat phasing signal DSC Routine and Distress Alerts A GMDSS Sea Area A3 is best described as being an area within continuous global coverage of the COSPAS-SARSAT system MF RT range of at least one shore station providing continuous MF DSC alerting 70º - 90º North and 70º - 90º South 70º North - 70º South A The control which automatically adjusts the Radio Frequency amplification is known as an Automatic Gain Control Automatic Frequency Control Automatic Mode Control Automatic Volume Control A The emission or mode control of an MF/HF transceiver increases the range of the transmitter reduces the received gain automatically allows the type of modulation to be selected allows fine tuning of the receiver A On an MF transceiver, DUPLEX operation is the use of one control to change RF gain and another control to the AF gain handset for MF RT and another handset for HF RT frequency to transmit and another frequency to receive simultaneously battery bank to power the transmitter and another battery bank for the receiver A The correct mode of emission for a RT distress message on 2182 kHz is R3E F1B H3E J3E A GMDSS Sea Area Al is best described as being an area within approximately 100 to 150 miles from the coast range of the Inmarsat system VHF RT range of at least one shore station providing continuous VHF DSC alerting MF RT range of at least one shore station providing continuous MF DSC alerting A On a transceiver, SIMPLEX operation is the alternate use of one frequency to transmit or receive use of one control for AF and RF Gain C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an use of one frequency to transmit and a second frequency to receive type of modulation used on 2182KHz A On VHF the transmitted power should be reduced to Give maximum range Use more battery energy Minimise interference Increase the volume of the received signal A A set of ITU RT paired frequencies can be described as single side band double sideband simplex duplex A The mode of emission used for voice on MF and HF is F1B A3E H3E J3E A A common abbreviation for the mode of emission for a RT distress message on 2182 kHz is AM FM SSB Telex A On a transceiver, DUPLEX operation is the use of one control for AF gain and RF gain antenna to transmit and receive frequency to transmit and a second frequency to receive frequency to transmit and receive A The emission or mode used for RT (voice) operation on MF is DSB SSB ISB FSK A The correct mode of emission for HF radiotelephony SSB transmission is G3E H3E F1B J3E A Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an Cau hoi A B C D Dap an On MF and HF transmitters the emission or mode control controls the selection of the ITU Channel adjusts the frequency selects the type of modulation adjusts the power output A One of the advantages of using J3E is the signal is less efficient than R3E the received signal is clearer than H3E less current is drawn from the batteries than H3E the signal contains less power than H3E A The correct mode of emission for a MF Radiotelex transmission is F1B G3E F3E J3E A Ship to ship Safety of Navigation RT communication on Ch.13 VHF uses a Common calling channel Semi-duplex channel Simplex channel Duplex channel A An Automatic Gain Control adjusts the upper or lower sideband radio frequency (RF) gain fine tuning of the received frequency audio frequency (AF) gain A Using high or maximum power on an MF transmitter would give a typical range of worldwide 50 miles 150 miles 20 miles A The maximum output power of marine VHF is limited to 100 Watts 25 Watts 10 Watt 50 Watts A ... of the received signal A A set of ITU RT paired frequencies can be described as single side band double sideband simplex duplex A The mode of emission used for voice on MF and HF is F1B A3E H3E