Correct Method Of The Atmosphere Absorption Loss In Narrowband RCS Test

Radar Cross Section (RCS) is a physical measurement for the energy ofelectromagnetic wave of the Radar target, and it is the reflection of radar frequency,target framework, material, polarization of incident field and antenna, etc. We canobtain the unique features of space targets based on RCS and achieve the goal toclassification. The energy of electromagnetic wave will loss when propagating in theatmosphere. Measurement of the target RCS is implemented through complicatedprocessing with the radar transmits power and receives power. So the measurement ofRCS is effected by the neutral atmosphere absorption. The model of RCS demarcationand computation can’t deal with the atmosphere absorption.The theory of atmosphere absorption is introduced in this paper. The definition andthe physical meaning of RCS are lay out, and the point of view that the atmosphereabsorption is the main factor to affect the precision of RCS measurement. Then thecommon demarcation and computation model of RCS measurement is analyzed, and theconclusion shows that dealing with the atmosphere absorption as a constant isunreasonable. In order to straighten up the shortcoming of current models, We putforward a new method for modifying the atmosphere absorption model according toseparating the atmosphere absorption factor. It can compute the atmosphere absorptionaccurately via making use of the proposed model. Additionally, the truncation error isanalyzed.The engineering computation method of atmosphere absorption for RCSmeasurement is designed based on the proposed model. And the influence ofatmosphere absorption to RCS demarcation and computation of radar target is analyzedthrough the examples of narrowband RCS measurement and typical electromagneticwave frequency atmosphere absorption computation. The results indicate that themodified model is efficient for RCS demarcation and computation.In order to assure the correction of the formula and data in our references and getmore accurate result in our computation, a set of model from these references of powerattenuation computation was researched and validated through simulating. We get thefine model and use it in our atmosphere absorb loss computation. The relation betweenthe atmosphere absorption loss of electromagnetic wave energy and the radar elevationis described by calculating using our model. At last, the simulating to track the demarcated secondary planet is lay out, the result shows that the proposed model andthe engineering computing method can obtain the RCS data exactly and effectively.The modified atmosphere absorption model and the engineering algorithm basedon the newest research results and character of shooting range can modify atmosphereabsorption of RCS measurement accurately. It can enhance the precision of dynamicRCS data processing, and provide the accurate data processing result for characteristicanalysis, feature extract and classification of radar targets.