Method for adjusting a measurement system comprising a tacheometer mounted on a carrier carriage traveling on a railway track undergoing work, a target fixed to a railway work machine, a set of data on a theoretical route of the railway, and a set of data on the positioning of noteworthy topographic singularities, in which method: - the carrier carriage is made to travel on the railway track in a working direction from a starting position to an arrival position near an arrival topographic singularity (58, 60) listed in the set of data on the positioning of noteworthy topographic singularities; - the carrier carriage is immobilized relative to the railway track in the arrival position; - with the carrier carriage immobilized in the arrival position, a sighting (64, 70) of the arrival topographic singularity (58, 60) is carried out using the tacheometer, and at least a distance, an azimuth angle and an elevation angle which are characteristic of the relative positioning of the tacheometer with respect to the arrival topographic singularity (58, 60) are measured, - with the railway work machine having been brought into the starting position, a sighting (66, 72) of the target is carried out using the tacheometer, and at least a distance, an azimuth angle and an elevation angle which are characteristic of the relative positioning of the tacheometer with respect to the target are measured, - coordinates of the arrival position of the carrier carriage in a floating reference frame are calculated, on the basis of the measurements taken during the sighting (62, 70) of the arrival topographic singularity (58, 60) and the sighting (66, 72) of the target, additional data relating to the starting position, as well as data on the positioning of the arrival topographic singularity (58, 60) read from the set of data on the positioning of noteworthy topographic features, and data relating to the theoretical route of the track read from the set of data on the theoretical route of the track, and then the coordinates of the arrival position of the carrier carriage are stored in the floating reference frame. - the carrier carriage is made to travel on the railway track in a working direction from a starting position to an arrival position near an arrival topographic singularity (58, 60) listed in the set of data on the positioning of noteworthy topographic singularities; - the carrier carriage is immobilized relative to the railway track in the arrival position; - with the carrier carriage immobilized in the arrival position, a sighting (64, 70) of the arrival topographic singularity (58, 60) is carried out using the tacheometer, and at least a distance, an azimuth angle and an elevation angle which are characteristic of the relative positioning of the tacheometer with respect to the arrival topographic singularity (58, 60) are measured, - with the railway work machine having been brought into the starting position, a sighting (66, 72) of the target is carried out using the tacheometer, and at least a distance, an azimuth angle and an elevation angle which are characteristic of the relative positioning of the tacheometer with respect to the target are measured, - coordinates of the arrival position of the carrier carriage in a floating reference frame are calculated, on the basis of the measurements taken during the sighting (62, 70) of the arrival topographic singularity (58, 60) and the sighting (66, 72) of the target, additional data relating to the starting position, as well as data on the positioning of the arrival topographic singularity (58, 60) read from the set of data on the positioning of noteworthy topographic features, and data relating to the theoretical route of the track read from the set of data on the theoretical route of the track, and then the coordinates of the arrival position of the carrier carriage are stored in the floating reference frame.