INVERSION OF SYNTHETIC APERTUR,E R,ADAR (SAR) - MSpace ...

Ground Range
l;l
2 sin0
Figure 1.2: Slant range and ground range.
The optical plocessols had gleatly contributecl to the SAR signal processing
in the ear'ly clays. In the ear-ly 1950's, the University of Illinois gloup
pelformed experiments to verify the Doppler bearn sharpening concept using
electronic circuitry. The electronic harclwale existing at the time, horvever,
had diffculties in manipulating the large amount of data and opelations requiled
fol implernenting the beam shalpening technique (Ulaby ef ø/. [t03]).
In 1953, a group at the University of Michigan begau to exarnine the possibility
of using coherent optics for reconstructing the SAR image from the I'aw
signal (Curtona et al. l22l). Until recent years, the cohelent optics approach,
sirnilar to the techlique of liologlapliic inage leconstruction, has been the
prirnary SAR processirg teclinique. In aclclition to the aclvautage of its relatively
fast processing tine, photoglaphic film provides a leasonabl¡' cornpact
mec{ium for stoling the immense arnount of ralv ancl processerl SAR clata,