The control of railway track position is an important application area for coordinate measuring optoelectronic systems. One of the methods for the railway track control consists in determination of railway track position relatively to reference marks, which are mounted along the track . In general case this system should be mounted on liner-tamper-surfacer and provide measurements of reference marks coordinates. Marks can be positioned up to 10 meters from track and measurements must be carried out in automatic mode. It has been decided to project the system on basis of inner-base rangefinder’s scheme .