Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Theory and simulation of ionospheric effects on synthetic aperture radar
AU - Belcher, David
AU - Rogers, Neil
PY - 2009/10
Y1 - 2009/10
N2 - Space-based synthetic aperture radar (SAR) necessarily involves imaging through the ionosphere. At low frequencies (VHF, UHF and L-band) the ionosphere will degrade the SAR image. Previous work has shown that the amount of image degradation strongly depends on the integrated strength of ionospheric turbulence, C k L. The focusing, sidelobes and integrated sidelobe ratio all depend on C k L in a manner that can be directly predicted by a simple analytic theory, which is reviewed and extended to cover any synthetic aperture length. Simulations of the ionosphere, using a thin phase screen parabolic equation approach, are performed under different ionospheric conditions for a number of possible SAR systems and the results compared with the analytic theory. It is concluded that, provided that the scattering is weak, the theory represents a good predictor of SAR performance, even at UHF. The known statistics of C k L can therefore be used to predict the performance of any trans-ionospheric SAR without performing a simulation.
AB - Space-based synthetic aperture radar (SAR) necessarily involves imaging through the ionosphere. At low frequencies (VHF, UHF and L-band) the ionosphere will degrade the SAR image. Previous work has shown that the amount of image degradation strongly depends on the integrated strength of ionospheric turbulence, C k L. The focusing, sidelobes and integrated sidelobe ratio all depend on C k L in a manner that can be directly predicted by a simple analytic theory, which is reviewed and extended to cover any synthetic aperture length. Simulations of the ionosphere, using a thin phase screen parabolic equation approach, are performed under different ionospheric conditions for a number of possible SAR systems and the results compared with the analytic theory. It is concluded that, provided that the scattering is weak, the theory represents a good predictor of SAR performance, even at UHF. The known statistics of C k L can therefore be used to predict the performance of any trans-ionospheric SAR without performing a simulation.
U2 - 10.1049/iet-rsn.2008.0205
DO - 10.1049/iet-rsn.2008.0205
M3 - Journal article
VL - 3
SP - 541
EP - 551
JO - IET Radar Sonar and Navigation
JF - IET Radar Sonar and Navigation
SN - 1751-8784
IS - 5
ER -