digital selective calling的意思|示意

Digital selective calling (DSC) is a way for two-way radios to transmit a specific set of codes that are used to identify and contact vessels in an emergency situation. It is a way for a ship to communicate with another ship or shore station without relying on a watch officer.

DSC uses radio frequencies to transmit a digital code, called a message header, that contains the receiver’s identity and the type of emergency message being sent. The message header is followed by the emergency message itself, which contains the distress message.

When a distress message is sent, it contains the distressed vessel’s position and other necessary information. It is then broadcast on a designated distress frequency. All ships within range of the distress message will be able to receive it and, if they are equipped to do so, they can respond by transmitting a reply message with their position and other necessary information.

Once a reply message is received, the sender of the distress message can then contact the vessel and arrange for assistance. This helps to save time when a vessel is in distress, as it eliminates the need for a watch officer to call for help.

DSC is a crucial piece of life-saving technology that is vital for the safety of all vessels and those on board, and is now required by most governments in order to be able to navigate safely.