This is an open access article published by the IET under the Creative Commons Attribution-NoDerivs License (http://creativecommons.org/licenses/by-nd/3.0/)
Compared with the repeat-pass interferometry synthetic aperture radar (InSAR) system, the single-pass InSAR system, such as TanDEM-X and TanDEM-L, has better performance and less decorrelation. However, InSAR measurements can be seriously influenced by the background ionosphere, especially for InSAR system operating at lower frequencies, such as L-band and P-band. Low-frequency signals propagating in the ionosphere suffer serious group delay, dispersion, scintillation and Faraday rotation, which further induce the image shift and decorrelation of SAR interferometry pairs. Since the ionosphere shows significant space-varying and time-varying features, the conventional ionosphere spatial invariant model is invalid for space-borne single-pass InSAR system. It is supposed that the time variance of ionosphere in short integration time can be neglected for low-earth orbit InSAR system. The effect of the spatial variant ionosphere on single-pass InSAR measurement is analysed and a correction method for InSAR products based on the prior knowledge is presented in this paper. Simulations are performed by using total electron content data obtained from the international reference ionosphere model, and the results indicate the significant error induced by spatial variant ionosphere.
References
-
-
1)
-
3. Liu, J., Kuga, Y.: ‘Ionospheric effects on SAR imaging: a numerical study’, IEEE Trans. Geosci. Remote Sens., 2003, 41, (5), pp. 939–947.
-
2)
-
6. Krieger, G., Zan, F.D., Dekker, P.L., et al: ‘Impact of TEC gradients and higher-order ionospheric disturbances on spaceborne single-pass SAR interferometry’. IEEE Geoscience and Remote Sensing Symp., Milan, Italy, July 2015, pp. 4061–4064.
-
3)
-
1. Rosen, P.A., Hensley, S., Chen, C.: ‘Measurement and mitigation of the ionosphere in L-band interferometric SAR data’. IEEE Radar Conf., Washington, DC, USA, May 2010, pp. 1459–1463.
-
4)
-
7. Li, Y., Hu, C., Kong, S., et al: ‘Impacts of temporal-spatial variant background ionosphere on geosynchronous SAR interferometric phase screen’. IET Int. Radar Conf., HangZhou, China, October 2015, pp. 1–5.
-
5)
-
4. Meyer, F.J.: ‘Performance requirements for ionospheric correction of low-frequency SAR data’, IEEE Trans. Geosci. Remote Sens., 2011, 49, (10), pp. 3694–3702.
-
6)
-
8. Hu, C., Li, Y., Dong, X, et al: ‘Impacts of temporal-spatial variant background ionosphere on repeat-track GEO D-InSAR system’, Remote Sens., 2016, 8, (11), pp. 916–930.
-
7)
-
9. Moreira, A., Krieger, G., Hajnsek, I., et al: ‘Tandem-L: a highly innovative bistatic SAR mission for global observation of dynamic process on the earth's surface’, IEEE Geosci. Remote Sens. Mag., 2015, 3, (2), pp. 8–23.
-
8)
-
2. Ishimaru, A., Kuga, Y.: ‘Ionospheric effects on synthetic aperture radar at 100 MHz to 2 GHz’, Radio Sci., 1999, 34, (1), pp. 257–268.
-
9)
-
5. Krieger, G., Zan, F.D., Bachmann, M., et al: ‘Tropospheric and ionospheric effects in spaceborne single-pass SAR interferometry and radargrammetry’. European Conf. on Synthetic Aperture Radar, Berlin, Germany, June 2014, pp. 1–4.
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Analysis and correction of spatial variant background ionosphere impacts on single-pass InSAR system