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JERS-1 DInSAR$B$HCOI=BP>]J*(B
JERS-1 DInSAR and Terrain Objects

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Takako Sakurai-Amano, Mikio Takagi (Science University of Tokyo)
Shigeki Kobayashi (Kyushu Tokai University), Naoyuki Fujii (Nagoya University)

takako@tlab.te.noda.sut.ac.jp

Abstract:$B!!(BThe effects of terrain objects on the phase of Differential Interferometry have been investigated using JERS-1 SAR images. The phases of the unfiltered enhanced interferogram was compared with the filtered interferogram processed with the same parameters. The phase of cluttered areas in the unfiltered interferogram changes slowly but the phases of low magnitude areas are random on pixel-by-pixel basis. On the other hand, the phases of low magnitude areas are affected by nearby strong scatterers or could be mistaken as non-random area because the unit of randomness was larger.

1. $B$O$8$a$K(B

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Fig.1$B!!(BAn example of two-path differential interferogram of JERS-1 SAR images of Omaezaki, Shizuoka (part of scene D66-242) observed on May 4, 1998 and July 31, 1998.

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Fig.2 Simulated SAR image of Shimada city created from a modified DEM integrated with topographic map information.

Fig.3 Interferogram (phase) of Shimada city and its neibourhood.$B!J(Bfilter size: (a) variable 2-10$B!K(B, (b) variable 2-7, (c) variable 1-3, (d) no filter)

Fig.4 Interferogram (phase+magnitude) of Shimada city and its neibourhood. $B!J(Bfilter size: (a) variable 2-10$B!K(B, (b) variable 2-7, (c) variable 1-3, (d) no filter)

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(a)

(b)

(c)

(d)

Fig.5$B!!(BInterferograms of various terrain areas. (a) sea, (b) city center, (c) local airport, (d) sea port. (a1) no filter-phase, (a2) no filter-phase+magnitude, (b1) filter-phase, (b2) filter-phase+magnitude.

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Fig.6$B!!(BHistogram of interferogram$B!!(B(magnitude) of Fig.1

Fig.7 Interferogram patterns above and below threshold values.

Table$B#1!%(BPatterns of phase changes.

threshold value	areas>threshold value	areas<threshold value
20x10⁵	slow change	random+ slow change
15x10⁵	slow change	random+ slow change
10x10⁵	slow change	random+ slow change
5x10⁵	slow change+random	random

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Fig8.$B!!(BSagara corner reflector in the center of the circle. (a) interferogram$B!!(B(magnitude). (b) Interferogram. (magnitude + phase)

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