A method for geolocating a signal-transmitting device, the geolocation method comprising: - supplying first reception data, said first reception data resulting from the reception by a plurality of first reception stations of a first radio signal transmitted at a first frequency by the signal-transmitting device, said first reception stations defining a first geographic coverage zone, - calculating a first geographic position of the signal-transmitting device in the first geographic coverage zone from the first reception data, - detecting that the geographic position of the signal-transmitting device is included in a predefined second geographic zone the second geographic zone being included in the first geographic coverage zone, - transmitting a transmission instruction signal to the signal-transmitting device, the transmission instruction signal being intended to trigger the transmission of a second radio signal at a second frequency distinct from the first frequency by the signal-transmitting device, said first frequency being lower than the second frequency, - supplying second reception data, said second reception data resulting from the reception of the second radio signal by a plurality of second reception stations, said second reception stations being able to receive a radio signal at the second frequency transmitted from the second geographic zone, and - calculating a second geographic position of the signal-transmitting device in the second geographic zone from the second reception data, characterized in that - detecting that the geographic position of the signal-transmitting device is included in the predefined second geographic zone is achieved by comparing the first geographic position of the signal-transmitting device calculated to the coordinates of the second geographic zone, - transmitting the transmission instruction signal to the signal-transmitting device is achieved in response to the detection that the geographic position of the signal-transmitting device is in the second geographic zone. - supplying first reception data, said first reception data resulting from the reception by a plurality of first reception stations of a first radio signal transmitted at a first frequency by the signal-transmitting device, said first reception stations defining a first geographic coverage zone, - calculating a first geographic position of the signal-transmitting device in the first geographic coverage zone from the first reception data, - detecting that the geographic position of the signal-transmitting device is included in a predefined second geographic zone the second geographic zone being included in the first geographic coverage zone, - transmitting a transmission instruction signal to the signal-transmitting device, the transmission instruction signal being intended to trigger the transmission of a second radio signal at a second frequency distinct from the first frequency by the signal-transmitting device, said first frequency being lower than the second frequency, - supplying second reception data, said second reception data resulting from the reception of the second radio signal by a plurality of second reception stations, said second reception stations being able to receive a radio signal at the second frequency transmitted from the second geographic zone, and - calculating a second geographic position of the signal-transmitting device in the second geographic zone from the second reception data, characterized in that - detecting that the geographic position of the signal-transmitting device is included in the predefined second geographic zone is achieved by comparing the first geographic position of the signal-transmitting device calculated to the coordinates of the second geographic zone, - transmitting the transmission instruction signal to the signal-transmitting device is achieved in response to the detection that the geographic position of the signal-transmitting device is in the second geographic zone.