Method for characterizing the seat of a railroad track, device for viewing the inside of a ground and assembly for characterizing the seat of a railroad track comprising such a device

An assembly for characterizing a seat of a railroad track, comprising a light dynamic penetrometer, which includes:

• a ram head,
• a train of rods, equipped with a tip for penetrating the seat,
• measuring means for measuring the strength of the seat as a function of the depth,
• a device for viewing the inside of a ground, comprising an endoscopic camera for recording images, a sliding tube for the camera, which is suitable for being pushed into a hole formed in the ground, and measuring means for automatically and continuously measuring the position of the endoscopic camera while the camera slides inside the sliding tube, i.e., the depth at which the images are recorded, and
• a processing unit, configured to couple an analysis of the images, recorded by the device, with strength measurements of the seat, provided by the measuring means of the penetrometer, to characterize different layers of the seat,
• wherein the analysis of the images recorded by the camera as a function of the depth is done from the variation of different parameters relative to the recorded images and wherein the processing unit is capable of:
• i. automatically determining significant depth values, from which the various parameters relative to the recorded images and the resistance of the seat vary considerably, and
• ii. performing a statistical analysis of the significant depth values to estimate the depth of the layers of the seat.