A system for determining a geographical location of at least one radio signal transmitter located on the Earth's surface, the system comprising: - a set of satellites (SAT1, SAT2, SAT3) provided with receiving antennas (ANTI, ANT2, ANT3) configured to receive said signals, forming a main extended interferometry device; - an intersatellite relative metrology device configured to determine relative positions of said satellites (SAT1, SAT2, SAT3) to one another, comprising at least one dedicated sensor (CAPTd_1, CAPTd_2, CAPTd_3) of each satellite (SAT1, SAT2, SAT3) and intersatellite communicators (COMM1, COMM2, COMM3), - a dating device (DAT1, DAT2, DAT3) for said received signals from said determination of the relative positions of said satellites (SAT1, SAT2, SAT3) to one another, provided by said intersatellite relative metrology device, based on measurements of pseudodistances by PRN code correlation and by clock synchronization of said satellites through time transfer between satellites, - a secondary interferometry device comprising at least one set of at least three antennas (ANT21_3, ANT22_3, ANT23_3) of a satellite - a ground base station, - a transmission device of measurements acquired at the satellites to the ground base station; and - means for determining an absolute position of at least one of the satellites (SAT1, SAT2, SAT3), the set of satellites comprising a main satellite (SATP) and at least one secondary satellite (SATS1, SATS2), said main satellite (SATP) comprising said transmission device comprising a single antenna (ANT1_P), and being configured to collect the set of said received signals, said relative positions and said datings (DATP, DATS1, DATS2) transmitted by said set of satellites, and to transmit these to said ground base station, and means for determining an geographical location of said transmitter which are provided within said main satellite (SATP), said secondary interferometry device being configured to provide an approximate geographical location of said transmitter configured for the initialization of a precise geographical location of said transmitter by the main extended interferometry device. - a set of satellites (SAT1, SAT2, SAT3) provided with receiving antennas (ANTI, ANT2, ANT3) configured to receive said signals, forming a main extended interferometry device; - an intersatellite relative metrology device configured to determine relative positions of said satellites (SAT1, SAT2, SAT3) to one another, comprising at least one dedicated sensor (CAPTd_1, CAPTd_2, CAPTd_3) of each satellite (SAT1, SAT2, SAT3) and intersatellite communicators (COMM1, COMM2, COMM3), - a dating device (DAT1, DAT2, DAT3) for said received signals from said determination of the relative positions of said satellites (SAT1, SAT2, SAT3) to one another, provided by said intersatellite relative metrology device, based on measurements of pseudodistances by PRN code correlation and by clock synchronization of said satellites through time transfer between satellites, - a secondary interferometry device comprising at least one set of at least three antennas (ANT21_3, ANT22_3, ANT23_3) of a satellite - a ground base station, - a transmission device of measurements acquired at the satellites to the ground base station; and - means for determining an absolute position of at least one of the satellites (SAT1, SAT2, SAT3),