International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
appears to be greater near +45° ellipticity angle,
indicating higher circular response. Water is an
excellent specular reflector, thus leading to
greater forward scattering and less backscatter
of the EM waves.
EE EEE
Ee E Tr RT
*
Se
—
Co-polarized Signature ^ Cross-polarized Signature
Figure 3.4(a): Polarimetric response of Waterbody
4. CONCLUSION
In this study, a tool named “POLSIC”, with
basic capability to calculate and represent 3D
Polarimetric signatures (Co-polarized and Cross
polarized) has been developed, still in an
experimentation phase, in order to encourage
and develop Polarimetric signature studies of
various possible targets/class. The polarimetric
signatures generated for various urban targets,
were studied and following conclusions were
made: It was found that all the built up
structures (buildings, roads and bridge) and the
agriculture fields/vegetated areas showed
greater Co-polarization response than the Cross
polarization response. The open field and water
body showed greater Cross polarization
response as compared to the above mentioned
features. The vegetated land, built up-1(within
city), built up within water body, road-1 were
found to have an overall higher polarimetric
response (backscattered power) as compared to
plantation, built up-2, bridge, road-2, open field
and minimum in case of water body, due to
factors like surface roughness and orientation of
the target with respect to the radar look angle.
Also rough surfaces like buildings, trees,
agricultural fields, etc., cause greater multiple
scattering as compared to the smoother surfaces
like fallow land, water body, etc. The smoother
surfaces (water body, open field) have lower
backscattered power values. The minimum
intensity indicates the pedestal height of the
polarization signature. The rougher surfaces
have more multiple scattering and therefore
540
higher pedestal heights than the smoother
surfaces. Thus, the shape of the signature also
indicates the scattering characteristics. In case
of built up areas, roads and bridge, it is found
that the predominant polarization intensity
differs with the height, shape and the alignment
direction of the former, thus giving differences
in the polarimetric responses of each.
ACKNOWLEDGEMENTS
The authors are thankful to Dr. S.K. Pathan and
Ms. Shweta Sharma for her valuable guidance
and support.
REFERENCES
References from Journals:
[1] Fiset R. and M. Farhat, A low cost
polarimetric response tool using
spreadsheets, International Geoscience and
Remote Sensing Symposium (IGARSS
2001), 9-13 July, 2001.
References from Books:
[2] Fawwaz T. Ulaby, Charles Elachi, Radar
Polarimetry for Geoscience Applications,
Artech House, Boston, London,1990, pp.
17-50. ;
[3] Floyd M. Henderson, Anthony J.Lewis,
Principles and Applications of Imaging
Radar, Manual of Remote Sensing, Third
edition, Vol.2, pp.120, 140, 296-299.
[4] lain H. Woodhouse, Introduction to
Microwave Remote Sensing, CRC press,
2006.
Reference from Websites:
[5] Paper on *A low-cost Polarimetric response
tool using spreadsheets", Canadian Space
Agency, Canada. (http://www.asc-
csa.ge.ca/pdt/radarsat? polarimetry toolsdb
-pdf)
[6] Tutorial on Radar Polarimetry by Natural
Resources Canada.
(http://www .nrcan.ge.ca/earth-
sciences/geography-boundary/remote
sensing/fundamentals/1025)
