Patent Document ID: 10041785
Application ID: 15555429
Patent Flag: 1

Claim One:
1. A method of characterizing a wet paint layer stack of a painted body, comprising at least two wet paint layers, by individual wet paint layer parameters, based on fitting to a physical model, the method being carried out by a sensor system in a non-contact manner, the sensor system comprising an emitter system for emitting THz radiation, a detector system for detecting THz radiation, and a processing unit operationally coupled to the emitter system and the detector system, the method comprising: emitting, by the emitter system, a THz radiation signal towards the painted body such that the THz radiation interacts with the wet paint layer stack, detecting, by the detector system, a response signal being the THz radiation signal having interacted with the wet paint layer stack; determining model parameters of the physical model by optimizing the model parameters such that a predicted response signal of the physical model, which approximates the interaction of the THz radiation signal with the wet paint layer stack, is fitted to the detected response signal, wherein at least some of the model parameters are indicative of individual optical properties of the wet paint layers and of a wet paint layer thickness; and determining, from the determined model parameters, the individual paint layer parameters of at least one of the wet paint layers, including at least one predicted dry paint layer thickness.