Abstract: A process for initiating maritime radio communication, directed toward the recipient vessel's location, and exclusive of all other vessels outside the geographically-defined box. An airborne electro-optical or infrared sensor detects the presence of vessels in the maritime domain. Established geolocation techniques are employed to determine the approximate geographical location (latitude and longitude) of the target vessel. The derived geographical location of the target vessel is used to encode a Digital Selective Calling (DSC) Geographical Area Call, in the Very High Frequency (VHF) band, for the purpose of establishing radio communications. The process allows for geographically selective communications without previous knowledge of the target vessel's Maritime Mobile Service Identity (MMSI) and without the target vessel's assistance in determining its geographical location.

Abstract: A device and process for selectively communicating a digital audio message to a maritime vessel equipped with a Digital Selective Calling radio when the vessel is within a geographic area. The process involves steps of inputting geographical location information for a sensed maritime vessel to a computer processor; creating signal formatting instructions for a Geographical Area Call to the vessel that rings the vessel's radio, and then automatically tunes the radio to a clear frequency to receive a digital audio message; transmitting the signal to the vessel; and, transmitting the digital audio message to the vessel on the clear frequency. Optionally, the process includes a step of receiving input of frequency use data from a radio receiver/scanner to select a clear frequency to send the digital audio message. The device of the invention includes a computer readable medium storing instructions for implementing the process.