合成孔徑雷達(dá)原理

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 回波信號頻率ff00t0stT 20stT 20tt發(fā)射信號相位（線性相位）回波信號相位（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 2s1fTd1d2s1fffT a0s2v1xRT 00assRR1x=2vT2L0sxRLDsx1xD2 ssT 2T/2*11r1r1r1r1T 2T 2R ( )s (t)s (t)dts (t)s (t)dt乘法器積分器sr1(t)延遲線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 2aa02vKR00t2asa

6、sasRR111t=K T22 v Lv T 時間分辨力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第一模糊區(qū)22r1R(tT )c2rr1Tf11r2RtTc222Rtc21rttT有可能有：rmaxcf,

7、2Rmaxr2RTcr12(n1)cncf2R2R 從所有模糊區(qū)來的回波輸出總功率從規(guī)定的測繪帶來的回波輸出總功率從第一旁瓣引起的模糊區(qū)來的回波輸出功率從測繪帶來的回波輸出功率24asr24a saG RRG R Ga：表示第一模糊區(qū)的天線增益 Ra：模糊區(qū)的斜距sa ：模糊區(qū)的方位分辨率44aR Rsas2ards02vffTR ssasa0araL Lv T,R2v f， a為天線方位向波束角sxasxD,D2arsvfasa rrvv Tfs Es( )s2sin2N1xE2sinx距。aarrvxv Tf nnn0, 1, 2,2 x2xaR 從所有方位模糊區(qū)來的回波輸出總功率 從測繪帶來的回波輸出功率 從第一模糊區(qū)來的回波輸出總功率從