Results and Conclusion
Figure 3 shows the interferogram of karakax site after flat-earth phase removal.

The estimations of interferometric parametric is shown in table II. These results are calculated by 15 ground control points, which are selected from 1:5000 relief map of study area.

The unwrapped phase calculated by weighted least –squares algorithm is shown in Figure 4 , and Fig. 5 is DEM of Karakax after geocoding.

The accuracy of karakax SIR-C DEM’s is evaluated by ground control points, and the average accuracy measured is 16.14m rms.


Table II the estimation of interferomeric parameters of SIR-C data of karakax area

Baseline (m)	140.849
Baseline rate	-0.0287121
Baseline angle (radian)	0.866694
Baseline angle rate	0.0
Platform altitude (km)	220.023
Platform altitude rate	-4.20959e-05
Constant phase (radian)	-14.7618
Parameter quality	2.38291

A SAR interferometry processor and its main algorithms along with some results has been presented. It is capable to process quadrant size images although phase unwrapping keeps being the critical step depending on the scene relief. Further work will be oriented to adopt a more rapid InSAR processing strategy.

Acknowledgements
This work is part of SIR-C/X-SAR program and supported by Chinese Hi-Tech( 863) program and National Natural Science Foundation of China(49781001). The authors acknowledge the NASA/JPL for providing the SIR-C images.

Reference

• H.A.Zebker, C.L.Werner, P.A.Rosen , and Scott Hensley, “ Accuracy of Topographic Maps Derived from ERS-1 Interferometric Radar”, IEEE Trans. Geosci. Remote Sensing, Vol.32, pp. 823-836, 1994
• S.N. Madsen, H.A.Zebker, and Jan Martin, “ Topographic Mapping Using Radar Interferometry : Processing Techniques”, IEEE Trans. Geosci. Remote Sensing, vol.31, pp. 246-255, 1993
• Wang Chao, “ DEM Generation of SIR-C Interferometric data”, Journal of Remote Sensing (in Chinese with English abstract), Vol.1, No.1, pp 46-49,1997
• Daniel Carrasco, Susanna Sanz, Ricardo Sousa, and Antoni Broquetas , “The Developing of a Wide Area Interferometric Processor” , Fringe’96
• Wang Chao, Zhang Hong, Pan Guangdong and Yang Qingyou, “ Retrieval of DEM from SIR-C Data in Kunlun Mountain, West China, Proceedings of IGRASS’99, Hamburg, Germany, 1999

Fig. 1 Framework of interferometric SAR data processor for DEM




Fig.2 The interferomeric coherence map Of Karakax site




Fig.3 the interferogram of Karakax site after flat-earth phase removal




Fig.4 The unwrapped phase calculated by weighted least –squares algorithm




Fig.5 SAR image of Karakax area overlaid with DEM

Page 2 of 2
| Previous |