The doctoral thesis is devoted to the development of methods to improve the technical and operational characteristics of ship radio and navigation facilities through their integration and joint data processing in the condition of maintaining the basic composition of ship equipment, practical user needs – officer of the watch and taking into account global trends in marine technology.
In the thesis the new ideas for the combined using of observation data from the independently developed and implemented according to the requirements of the international concept of SOLAS navigation systems - automatic identification system (AIS), global navigation satellite system (GPS) and terrestrial radio systems using digital selective call (DSC) and radiotelephony that allowed to obtain new qualities in radio communication control and navigation outsight.
It is proposed to use a graphical interface for monitoring / control of radio communication, which allows increasing the efficiency and reliability of the address radio communication, to provide standardization of the user interface in contrast to the variety of button instrument interfaces of radio equipment from outnumbered manufacturers.
Currently AIS is an obligatory equipment to be carried on board all vessels. AIS provides for the exchange of information which includes vessel’s identification number (MMSI). Electronic chart display and information system (ECDIS) or another multifunction information display, while operating with AIS, enables it to indicate vessels within the AIS operating area, i.e. approximately 30 nautical miles, and to reflect them on ECDIS or information display.
The combination of the very high frequency (VHF) DSC equipment with the AIS – Information display allows:
– to eliminate, practically, the procedure of DSC forming while substituting manual operations by means choosing AIS target of the vessel to be called on the Information display; and
– to provide identification of a calling vessel on the electronic chart and thus to make the process of attachment of the called/calling vessel to the navigation situation automatically. A calling vessel can be indicated on the display by a blinking mark which will allow the officer of the watch quickly estimate the navigational situation and make an effective decision. The unique character of the vessel’s identification is provided by the presence of vessel identifier (MMSI) both in DSC and AIS. It gives the ability of automatic attachment the calling vessel to the current navigation situation represented on a navigation display.
The choice of communication interface for remote handling the radio communication modules is grounded and investigated. Standard of International Electrotechnical Committee IEC 61162-1/2 is selected for serial data exchange.
A method of automatic identification (AI) of radiotelephone transmissions and transfer of additional information using the modern technology of digital watermarking has been developed. Audio watermarking refers to inaudible embedding of additional data just into the post microphone signal, using standard marine installations without any additional radio channel resources. The addressed,
properly identified VHF radiotelephone communication is very important for safe navigation. AI, in turn, ensures efficient messaging from the very beginning of a radio transmission, while eliminating the human factor inherent in voice identification. AI allows identifying anonymous, intentionally compromised and harmful transmissions such as transmission button falling back in a VHF transceiver.
AI makes possible integrating MMSI detected data and AIS data for graphic display of the transmitting station.
Algorithms for audio watermarking were designed application in the real VHF radio channels, provided that the influence of all possible interferences (attacks) is taken into account. The problem of compromise parameters optimization for algorithms in the plane amount of information - signal quality - noise immunity was analyzed. It is proved that the best audio watermarking characteristics may be
obtained algorithms for data embedding in the frequency domain of discrete Fourier transform and using an informed encoder.
Mathematical modeling of algorithms is performed. Experimental prototypes of the hardware and software complexes of the integrated radio communication and navigation system and AI system of radiotelephone transmissions in the real maritime VHF channels are developed.
Keywords: digital selective calling, automatic identification system, very high frequency, radio telephony, interface, identification, digital watermarking, information
