Method for providing estimated values of an environment characteristic by means of sensors arranged in mobile data sources, wherein - virtual measurement stations are in each case defined by a station position and a coverage region, - the mobile data sources in each case store a plurality of measurement values of the environment characteristic at respective measurement positions at respective measurement times in a pre-buffer and form a measurement value vector from the stored measurement values and determine, by means of a pre-fusion, a source estimated value on the basis of the measurement value vector, wherein a reference position and a reference time are assigned to the source estimated value and, by way of the pre-fusion, the measurement values of the measurement value vector are in each case weighted depending on the spacing of the measurement position of the measurement value from the reference position and/or depending on the spacing of the measurement time of the measurement value from the reference time, - each mobile data source send its source estimated value, the reference position thereof and the reference time thereof to a source-external computation device, and - the source-external computation device in each case assigns the source estimated values of the mobile data sources to a respective coverage region of at least one of the virtual measurement stations on the basis of the respective reference position and, for each virtual measurement station, determines a station estimated value of the environment characteristic at the station position for a predetermined estimated time by means of a main fusion, wherein, by way of the main fusion, the source estimated values assigned to the coverage region are in each case weighted depending on the spacing of the reference position of the source estimated value from the station position and/or depending on the spacing of the reference time of the source estimated value from the estimated time. - virtual measurement stations are in each case defined by a station position and a coverage region, - the mobile data sources in each case store a plurality of measurement values of the environment characteristic at respective measurement positions at respective measurement times in a pre-buffer and form a measurement value vector from the stored measurement values and determine, by means of a pre-fusion, a source estimated value on the basis of the measurement value vector, wherein a reference position and a reference time are assigned to the source estimated value and, by way of the pre-fusion, the measurement values of the measurement value vector are in each case weighted depending on the spacing of the measurement position of the measurement value from the reference position and/or depending on the spacing of the measurement time of the measurement value from the reference time, - each mobile data source send its source estimated value, the reference position thereof and the reference time thereof to a source-external computation device, and - the source-external computation device in each case assigns the source estimated values of the mobile data sources to a respective coverage region of at least one of the virtual measurement stations on the basis of the respective reference position and, for each virtual measurement station, determines a station estimated value of the environment characteristic at the station position for a predetermined estimated time by means of a main fusion, wherein, by way of the main fusion, the source estimated values assigned to the coverage region are in each case weighted depending on the spacing of the reference position of the source estimated value from the station position and/or depending on the spacing of the reference time of the source estimated value from the estimated time.