Abstract: Systems (100) and methods (400) for providing Digital Selective Calling (“DSC”) based services. The methods involve: using Space-Born Maritime (“SBM”) receivers of satellites (104) deployed in space as a satellite constellation to collect and process DSC emergency messages transmitted from DSC transmitters of terrestrial radios; using the satellites to position validate the DSC emergency messages; determining first positions of the DSC transmitters in transit based on geolocation data and time location data respectively assigned by the satellites to the DSC emergency messages; and validating the first positions to more precise second positions based on results of cross-correlations of the geolocation data and time location data with Automatic Identification Systems (“AIS”) data obtained for the DSC transmitters.

Abstract: Systems (100) and methods (400) for space-based geolocation. The methods involve receiving by at least two first satellites a maritime signal transmitted from a vessel on or near Earth. The first satellites are deployed in space so as to have overlapping coverage areas. The maritime signal (received at the at least two first satellites) is then used to determine a geographic location of the vessel on Earth using at least one of a Time Difference of Arrival (“TDOA”) and a Frequency Difference of Arrival (“FDOA”).

Abstract: Systems (100) and methods (400) for providing Digital Selective Calling (“DSC”) based services. The methods involve: using Space-Born Maritime (“SBM”) receivers of satellites (104) deployed in space as a satellite constellation to collect and process DSC emergency messages transmitted from DSC transmitters of terrestrial radios; using the satellites to position validate the DSC emergency messages; determining first positions of the DSC transmitters in transit based on geolocation data and time location data respectively assigned by the satellites to the DSC emergency messages; and validating the first positions to more precise second positions based on results of cross-correlations of the geolocation data and time location data with Automatic Identification Systems (“AIS”) data obtained for the DSC transmitters.

Abstract: Systems (100) and methods (300) for providing Digital Selective Calling (“DSC”) based services. The methods involve: receiving, by a satellite (104) deployed in space, a DSC emergency message transmitted from a vessel (102) located in a body of water on Earth; and performing operations by the satellite to deliver the DSC emergency message to an appropriate authority located on Earth.