US Patent 11004228 Image based train length determination

In a method of determining a length of a train, a first camera at the head of the train acquires a first image of a first object on or proximate a path of the train and a second camera at the end of the train acquires a second image of a second object on or proximate the path of the train. A controller determines a length of the train based on a first geographical location associated with the first object in the first image and a second geographical location associated with second object in the second image. The first and second geographical locations of the first and second objects can be determined from corresponding prerecorded images of the objects that are geotagged with the geographical locations of the objects.