tailieunhanh - Wave Propagation 2010 Part 19

Tham khảo tài liệu 'wave propagation 2010 part 19', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 532 Wave Propagation So the instantaneous distribution of scattered field power in the space as the function of the positional angle 0 is formed by the union of elementary scatterer radar cross section 4 items plus 6 cosine oscillations. It is not difficult to see that every cosine functions are caused by the interference effect between the fields scattered by a pair of elementary scatterers forming the RCRO. The number of this pairs can be found with the use binomial coefficient where M is a number of values N is a number elements in the combination. In the case when M 4 N 2 we have C4 6. So the angular response function of the complex radar object considered will include 6 space harmonic functions as the interference result summarize how it follows from the expression 48 where the values d12 X4 - X2 d13 Xk - X3 d14 X4 - X4 d23 X2 - X3 d24 X2 - X4 d34 X3 - X4 are the space diversity of scattered elements for every interference pair. The space harmonic function yỊơịơk cos 2kdik0 corresponds to the definition that was done in Kobak 1975 Tatarinov et al 2007 . In accordance with this definition the harmonic oscillation in the space having the type cos 2Ăzỉớ is defined by the full phase 2kd 2 Ẳ 2dớ the derivative from which is the space frequency fgp 2d Ằ having the dimension Rail . The period TSp 1 fsp 2 2d has the dimension Rad which corresponds to this frequency. So a full power distribution of the field scattered by complex radar object is an union of the interference pictures which are formed by a collection of elementary two-points interferometers. Thus we can write a scattered power random angular representation depending on the positional angle in the form M c p ff E 2ỉdơiơk cos 2kdik0 m l 1 where c C J is combinations number M is a full number of RCRO elementary scatterers. It was demonstrated above that the electromagnetic field Stokes parameter so S3 angular distribution at the scattering by two-point distributed object has the form so Ớ so sb 2y s cos 0 5ự