300 
DEM pixel spacing 
90 m*90 m 
DEM data size 
2000x2000 
Orbit ERS-1/2 
24221/04548 
Date acquired ERS-1/2 
1996-3-2/3 
wavelength 
5.6cm 
azimuthxrange pixel spacing 
4.040m x 7.904m 
time of first state vector 
73128.364 s 
azimuth line time 
6.0244484e-004 s 
semi-major axe of the Earth 
6378137.0000 m 
semi-minor axe of the Earth 
6356752.3141 m 
Table 1: Simulation parameter 
Fig. 3 the external DEM 
Flattened Synthetic Interferogram 
500 1000 1500 2000 
range pixels 
Fig. 5 the external DEM 
Fig. 4 represents the unflattened interferogram. One thing 
should be noticed that the interferogram is very dense. Fig. 5 
represents the flattened interferogram and its fringes compared 
to the Fig. 4 become sparse. We know the height ambiguity is 
about 150m by calculating the parameters of ERS-1/2. So the 
simulated interfergram should have about 3 fringe changes. 
Meanwhile from the trend of topographical changes of Fig. 4 
we can see the trend of the simulated interferogram match the 
external DEM very well. The result shows a good agreement 
between simulation and the theory. 
4. CONCLUSIONS 
An new interferogram simulator has been developed with real 
orbit parameters, real radar sensor parameters and geometry 
model. The test experiment shows that the simulator is reliable 
for the following reasons: the interferogram phase changes 
corresponds to the topographical changes and the trend of the 
simulated interferogram matches the external DEM very well. It 
is a good assistant tool not only for validaition of phase-to- 
height converion and geocoding processing, but also for D- 
InSAR processing. Future work is to pay more attention to 
improve the efficiency of our algorithm and further study the 
application of our simulation method. 
REFERENCES 
Zhong Lu, 2007, “InSAR Imaging of Volcanic Deformation 
over Cloud-prone Areas-Aleutian Islands,” 
PHOTOGRAMMETRIC ENGINEERING & REMOTE 
SENSING, vol.73, No.3, pp.245-257 
R. F. Hanssen, T. M.Weckwerth, H. A. Zebker, and R. Klees, 
1999 “High-resolution water vapor mapping from 
interferometric radar measurements,’’Science, vol. 283, pp. 
1295-1297. 
Fig. 4 the external DEM 
Curlander J. C., 1982, “Location of Spacebome SAR Imagery”, 
IEEE Trans, on Geoscience and Remote Sensing, Vol. GE-20, 
No.3, pp.359-364. SAR Toolbox algorithm specification, 
Earthnet online, ESA