A device for geolocating a radio signal-transmitting device, said signal-transmitting device transmitting a radio signal, the geolocation device comprising:
- a. a selection module for selecting a reference station (3, GWi) from among the plurality of reception stations (3, GWi) having received the radio signal (2),
- b. a module for defining a scanning zone (13) configured to define a scanning zone (13) as a function of the positions (Xi, Yi) of said reception stations (3, GWi),
- c. a subdivision module configured to subdivide the scanning zone (13) into a plurality of subzones (17) as a function of a scanning granularity,
- d. a module for calculating a degree of cumulative error configured to, for each subzone (17, 25, 28), calculate a degree of cumulative error of said subzone (17, 25, 28), the calculation of the degree of cumulative error of said subzone (17, 25, 28) comprising:
- determining a tested position (k,l) included in said subzone (17, 25, 28),
- calculating, for each reception station (3, GWi), a respective transmission error parameter () as a function of a date of reception (Ti) of the radio signal (2) by said reception station (3, GWi), of a date of reception of the radio signal (2) by the reference station (T0) of a speed of propagation (C) of the radio signal (2), of a distance () between the tested position (k,l) and said reception station (3, GWi) and of a distance () between the tested position (k,l) and the reference station,
- calculating the degree of cumulative error of the subzone (17, 25, 28) as a function of the transmission error parameters () calculated for all of the reception stations (3, GWi),
- e. a subzone selection module configured to select a subzone (22, 27) exhibiting a minimum degree of cumulative error as subzone (22, 27) of location of the signal-transmitting device (l),
- in which the module for defining the scanning zone is also configured to define a new scanning zone (23, 26), the new scanning zone (23, 26) including and being centered on the location subzone (22, 27) selected by the subzone selection module, the subdivision being also configured to define a new scanning granularity lower than the scanning granularity, the geolocation device being configured to iteratively geolocate the signal-transmitting device from the scanning zones and the granularity defined iteratively by the scanning zone definition module and the subdivision module, and in which, on each iteration, the new scanning zone (23, 26) is defined as equal to the location subzone (22, 27) selected by the subzone selection module augmented by a margin completely surrounding the location subzone (22, 27) and whose width is greater than the scanning granularity.