Study On The Radar Cross Section For Large Electric Objects

With the development of stealthy and anti-stealthy technique, the measuring and computational methods for the Radar Cross Section (RCS) of large electric objects are growing. In measurement, because of the cost of measuring a large electric object is very high, so the method measuring the scaling model becomes a hotspot in electromagnetic field. In computation, PO technique has been widely used to get the RCS of large electric objects modeled by NURBS both at home and abroad.The study of the RCS of large electric objects is a practical and difficult engineering problem. The paper applies the scaling method to reduce the measurement and high frequency approximation to simplify the calculation. The traditional scaling model lies in total space, but in practice, one usually faces some objects in half space, for example, a ship. So the formulas used to calculate the RCS scaling factors of some objects lying in half space are derived in this paper.The method commonly used for computing the RCS is as follows: the Gordon algorithm for objects described in flat facets; the stationary phase method and the Ludwig algorithm for objects modeled in NURBS. The author presents the method that merges the stationary phase method and the Ludwig algorithm together to calculate the PO integral formula. Finally, to improve the accuracy, the author studies the double reflection between the patches of an object, and derives the formulas in PO_PO.The scaling method of large electric objects and the single and double reflection of NURBS surfaces are mainly presented in this paper. The scaling method in half space, the method for merging the stationary phase method and the Ludwig algorithm to calculate the RCS of a NURBS surface and the PO_PO method to compute the double reflection of two NURBS surfaces are presented in this paper for the first time. The results shown in this paper proves that the methods are feasible.