The population of resident space objects (RSOs) has increased drastically during the past years. These objects became a great threat for active satellites. The consequences of a collision with orbital debris strictly depend on the size and velocity of the debris. Typical collision velocities range from seven to fifteen kilometres per second, depending on the collision angle. Such debris must be detected, tracked, and catalogued in order to avoid collisions. Here, object size-related parameters will be estimated by making use of a scaled inverse Radon transform (IRT). The scaled IRT is obtained by estimating the object spin rate. https://digital-library.theiet.org/content/journals/10.1049/iet-rsn.2018.5337