Egg quantity determination based on Characteristic Polarisation State

Introduction: Ultra wideband target identification is very useful in a number of applications such as military, security control, biomedical and internet of things. Intelligent fridges will become an important component of internet of things to improve quality of life. Monitoring the number of eggs in a fridge would be one application of this. As it can be known, RFID techniques can be applied to determine the rough location of an item such as a box of eggs but it cannot determine the exact quantity of eggs in the box. One possible solution is to add an RFID tag to every egg, which has disadvantages of cost and potential health risk. Therefore, UWB radar would be a useful complement to RFID in this case to determine items in a fridge and their quantity. Numerous applications on shape identification have been carried out by using the CNR method [1-4]. In these papers, people can distinguish a sphere and a cylinder or other objects well by comparing the location of independent complex natural poles. Therefore, this would provide a simple way to distinguish milk bottles and egg boxes. Nevertheless, to the authors’ knowledge, there is nothing about how to determine the exact quantity. A novel method, CPS [5] has been proposed recently to observe the target polarisation. Successful story has been revealed to differ two L-shape targets with different wire length [6]. Two orthogonal linear polarisations, which are horizontal and vertical polarisation are illuminated and measured in cross and co-polarisation. Then characteristic angle in accordance to CPS is evaluated in order to have the ability to discern the number of eggs.