Ionospheric effects on SAR imaging
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Summary
This project investigates
the effects of ionosphere to the SAR imaging. A homogeneous ionosphere
is assumed in the analytical study. The irregularity of the ionosphere
is given by the two-parameter spectrum. The SAR image resolution is
obtained by computing the 3 dB width of the second order of the
ambiguity function. Results indicate a substantial change in azimuthal
resolution caused by the ionosphere for a UHF-VHF SAR system. The
change of range resolution is negligible. The analysis also indicates
that Faraday rotation is significant for a UHF-VHF SAR system. A
numerical model is developed to further evaluate effects of the
ionosphere on SAR imaging. The horizontal structure of the ionosphere
is described by the 1-D two-parameter spectrum. The Chapman formula is
used to generate the vertical profile of the electron density of the
ionosphere.
Real time
global Total Electron Content (TEC) variation map by JPL
Diagram
of the numerical model structure
Related publications
- J. Liu, Y. Kuga, A. Ishimaru,
X. Pi, and T. Freeman, "Ionospheric
effects on SAR imaging: a numerical study," IEEE Transactions
on Geoscience and Remote Sensing, vol. 41, no. 8, pp. 1834-1843,
May 2003.
Sponsored by JPL
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