Automated Tie Locating Analysing System (ATLAS) is a tie (sleeper) mapping system to automatically detect, in real time, the location of sleepers along the railroad track.  Installed on a Plasser tamping machine, the system allows a fully automatic operation of the tamping machine on track, even if the sleeper spacing is irregular. The system further allows individual spacing of multiple tamping heads installed on the same tamper.

The ATLAS is installed on the front end of the tamping machine, up to 10 m ahead of the tamping units.  During tamping operation the ATLAS is used to automatically detect the distance from a known reference point along the track to each individual sleeper. After plausibility calculations, which determine if the detected sleepers are in an expected location, both sleeper locations, together with sleeper certainty information (both sleeper ends detected, only left sleeper end detected, only right sleeper end detected, inserted sleeper because expected at this location, slewed sleeper) are sent to the control logic circuitry for the tamping cycle operation.  From this information the tamping cycle control logic calculates the distance between the sleepers, which is then used to position the individual tamping heads centred above each sleeper.

Once the correct tamping head location is attained, the tamping cycle is automatically initiated.  If more than one tamping head is used on the tamping machine, the sleeper location information is used to individually adjust the distance between the tamping heads allowing automatic operation of the tamping machine, even on very unevenly spaced sleeper track (wood sleeper track).