Radar images of vehicles based on SAR/ISAR processing

The purpose of this article is to propose extended functions for an existing HF sensor. The existing application is based on communication between the HF sensor (i.e. the radar) and a card located inside a vehicle. The detection and communication between the sensor and the card permit the expected payment transactions for, e.g., road tolls. In order to avoid fraud (a card identified as ´little car´ category in a big lorry for instance) and classify the vehicles, it could be interesting to compare information coming from the card and information from physical measurement (knowledge of the real size of the vehicle for instance). Furthermore, the number of passing vehicles is an important parameter for managing a motorway. We briefly bring up the SAR theory to explain how the velocity of a vehicle can be used to discriminate simple reflectors. We describe the system to which we apply the ISAR processing: geometric context and relative constraints. We discuss the different ways to adjust the SAR/ISAR processing to our problem as 2D basic processing. Some basic applications are described. We develop the problems due to the constraints of the radar system and ISAR processing.