合成孔径雷达原理课件.ppt

1、WhrLsWR0rxpLmaxRR0Lminx220apRR(xx )0apRxx2ap220ap00(xx )RR(xx )R2R0jt0s (t)Re e002 f0j (t-)0rs (t)Re Ke02Rc22apap00000 xxxx2R2Rc2RccR2ap00r0(xx )2Rs (t)Re Kexp jtccR2ap002 (xx )4 RjjRj trs (t)eee0cf2ap0r02 (xx )4 Rs (t)costR123 122aaxv t22aa302 v (tt )R pa 0 xv t2220a0at00004 R2 v (tt )2v1 dft-f(tt

2、)2dtRR2ad002vf(tt )R 2aa02vkR 回波信号频率ff00t0stT 20stT 20tt发射信号相位（线性相位）回波信号相位（二次相位）t00tt0ttdf00tt0tt0df0ss00aL /2Ttttv2222asasasd1000a0a02vL2vL2vTfttR2vR2vR2 0tt0ttss00aL /2Ttttv2222asasasd2000a0a02vL2vL2vTfttR2vR2vR2 2aadd1d2ss002v2vfffTLRRs0saaLRTvv2a0ad0a2vR2vfRv22a020a02 v (t t )jRj K (t-t )rs (t)e

3、e2aa02vKR 1, 0tTta(t)rect()=T0,tT 0t0px02aj K trs (t)a(t)e2a+j K t-j t-S( )=a(t)eedt2iat- K t iad2 K t0dt a2 K t(t) kat2 Kk2aktj( tK t )tS( )=a(t)edt2at-K t(t)2aK t2kkkkkk(t )t(t)t(t )(t ) (tt )(tt )2! kt-t2kkkk(t )t(t)t(t )(tt )2k2kkkkktjt(t )j(t ) 2 (t t )ktS( )a(t )eedt 2kkka kj t(t )-j t - K t -

4、kk44aka(t )a(t )S( )2eeK(t )taa(t)S()Ka1S( )rectK2a( )4 K4 p2(x2)p1(x1)R0rxx=0t=0 x=Lsf00tTs/2Ts2ads02vfTR21xxx 2atx v 1t021axtttv aaxv tad1a102vf(xx )Rad2a202vf(xx )Raad1d221002v2vff(xx )xRRp2回波p1回波tfff1f21/Ts1jt1sts (t)rect()eT2jt2sts (t)rect()eTs1s1sT2jtjt1s1sT2()Tsin2S ( )eedtT()T 2s2s2sT2jtjt2s

5、2sT2()Tsin2S ( )eedtT()T 2s1fT d1d2s1fffT a0s2v1xRT 00assRR1x=2vT2L0sxRLDsx1xD2 ssT 2T/2*11r1r1r1r1T 2T 2R ( )s (t)s (t)dts (t)s (t)dt乘法器积分器sr1(t)延迟线R11()2aj K tr1s (t)e222aaaaT/2T/2j K tj K (t)j Kj2 Ktas11sasT/2T/2sin( K T )R ( )eedteedtTK T0as 1K T 1as1K T 1as22K Tas1K Taxtv as1tK T 2aa02vKR00t2as

6、asasRR111t=K T22 v Lv T 时间分辨力0sxRLDxta1 Dt2 v sax1x= t vD2 i0h(t)Ks (tt)22tr34PGP4R22td340nP GSfT fN4R kT BF fdT faxRTv D23rt330nxaf f PGSN2 4R kT BF D v avtrPP f23av330 nxaP GSN2 4R kT F D ve24 AGexyAD D82avxy30naP D DSN512R kT F vp1回波 p2回波t1t2Tr第一模糊区22r1R(tT )c2rr1Tf11r2RtTc222Rtc21rttT有可能有：rmaxcf

7、,2Rmaxr2RTcr12(n1)cncf2R2R 从所有模糊区来的回波输出总功率从规定的测绘带来的回波输出总功率从第一旁瓣引起的模糊区来的回波输出功率从测绘带来的回波输出功率24asr24a saG RRG R Ga：表示第一模糊区的天线增益 Ra：模糊区的斜距sa ：模糊区的方位分辨率44aR Rsas2ards02vffTR ssasa0araL Lv T,R2v f， a为天线方位向波束角sxasxD,D2arsvfasa rrvv Tfs Es( )s2sin2N1xE2sinx距。aarrvxv Tf nnn0, 1, 2,2 x2xaR 从所有方位模糊区来的回波输出总功率 从测绘带来的回波输出功率 从第一模糊区来的回波输出总功率从测绘带来的回波输出功率rsin (D/ )E(D/ ) Dswrs2sin (2N+1)xsinDEE E2D(2N+1)x 21,D2 xDxsD2aarsvvfxsardsvffABCWR1R2 测绘带、斜距与天线俯角