Analysis of Hypersonic Platform-Borne SAR Imaging: A Physical Perspective
Abstract
:1. Introduction
- Based on the hypersonic platform-borne SAR signal propagation characteristics under plasma sheath, the hypersonic platform-borne SAR signal model is established. The transmission coefficient for SAR signal propagating through plasma sheath is computed by scatter matrix method. Furthermore, because the hypersonic platform-borne SAR signal propagates through the plasma sheath twice, the double transmission effect is coupled in the SAR signal model.
- By building a ground experiment system, SAR signal model under plasma sheath is verified experimentally. The plasma is produced by low-pressure glow discharge plasma generator. By comparing the theoretical and experimental results of time domain, frequency domain, and range compressed signal, the SAR signal model under plasma sheath is verified. From the theoretical and experimental results, it can be found that the plasma sheath will bring significant amplitude attenuation of SAR signal, which will cause the decrease of peak value of range compressed signal. This phenomenon is important and will significantly affect SAR imaging quality.
- The effect of attenuation characteristics caused by plasma sheath on SAR imaging is studied, and the key factors determining the SAR imaging quality are explored. The point target and the area targets imaging results under plasma sheath show that large attenuation will cause the focus depth decrease and even cause the target response to be submerged in the noise. In addition, by studying the key factors determining the SAR imaging quality under plasma sheath, it can be concluded that the severe degradation of SAR imaging appears at condition of high plasma sheath electron density and low SAR carrier frequency.
2. Model and Experiment
2.1. Introduction of Hypersonic Platform-Borne SAR Imaging under Plasma Sheath
2.2. Hypersonic Platform-Borne SAR Signal Model Coupling Plasma Sheath Effect
2.3. Experimental Verification of the SAR Signal Model under Plasma Sheath
3. Results and Discussion
3.1. Point Target Response under Plasma Sheath
3.2. Area Targets Response under Plasma Sheath
3.3. The Factors Determining SAR Imaging Quality
4. Conclusions
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
- Tang, S.; Guo, P.; Zhang, L.; So, H.C. Focusing Hypersonic Vehicle-Borne SAR Data Using Radius/Angle Algorithm. IEEE Trans. Geosci. Remote Sens. 2019, 58, 281–293. [Google Scholar] [CrossRef]
- Xu, X.; Liao, G.; Yang, Z.; Wang, C. Moving-in-pulse duration model-based target integration method for HSV-borne high-resolution radar. Digit. Signal Process. 2017, 68, 31–43. [Google Scholar] [CrossRef]
- Han, J.; Cao, Y.; Yeo, T.S.; Wang, F. Robust Clutter Suppression and Ground Moving Target Imaging Method for a Multichannel SAR with High-Squint Angle Mounted on Hypersonic Vehicle. Remote Sens. 2021, 13, 2051. [Google Scholar] [CrossRef]
- Han, J.; Cao, Y.; Yeo, T.-S.; Wang, F.; Liu, S. A novel hypersonic vehicle-borne multichannel SAR-GMTI scheme based on adaptive sum and difference beams within eigenspace. Signal Process. 2021, 187, 108168. [Google Scholar] [CrossRef]
- Wang, Y.; Cao, Y.; Peng, Z.; Su, H. Clutter suppression and GMTI for hypersonic vehicle borne SAR system with MIMO antenna. IET Signal Process. 2017, 11, 909–915. [Google Scholar] [CrossRef]
- Stollery, J.L. Hypersonic flight. Nature 1972, 240, 133–135. [Google Scholar] [CrossRef]
- Starkey, R.P. Hypersonic Vehicle Telemetry Blackout Analysis. J. Spacecr. Rocket. 2015, 52, 426–438. [Google Scholar] [CrossRef]
- Chen, J.; Liang, B.; Yang, D.-G.; Zhao, D.-J.; Xing, M.; Sun, G.-C. Two-Step Accuracy Improvement of Motion Compensation for Airborne SAR with Ultrahigh Resolution and Wide Swath. IEEE Trans. Geosci. Remote Sens. 2019, 57, 7148–7160. [Google Scholar] [CrossRef]
- Jin, G.; Dong, Z.; He, F.; Yu, A. Background-Free Ground Moving Target Imaging for Multi-PRF Airborne SAR. IEEE Trans. Geosci. Remote Sens. 2019, 57, 1949–1962. [Google Scholar] [CrossRef]
- Wei, X.; Chong, J.; Zhao, Y.; Li, Y.; Yao, X. Airborne SAR Imaging Algorithm for Ocean Waves Based on Optimum Focus Setting. Remote Sens. 2019, 11, 564. [Google Scholar] [CrossRef] [Green Version]
- Ding, Z.; Xiao, F.; Xie, Y.; Yu, W.; Yang, Z.; Chen, L.; Long, T. A Modified Fixed-Point Chirp Scaling Algorithm Based on Updating Phase Factors Regionally for Spaceborne SAR Real-Time Imaging. IEEE Trans. Geosci. Remote Sens. 2018, 56, 7436–7451. [Google Scholar] [CrossRef]
- Tian, J.; Wu, Y.; Cai, Y.; Fan, H.; Yu, W. A Novel Mosaic Method for Spaceborne ScanSAR Images Based on Homography Matrix Compensation. Remote Sens. 2021, 13, 2866. [Google Scholar] [CrossRef]
- Wang, Y.; Li, J.; Yang, J.; Sun, B. A Novel Spaceborne Sliding Spotlight Range Sweep Synthetic Aperture Radar: System and Imaging. Remote Sens. 2017, 9, 783. [Google Scholar] [CrossRef] [Green Version]
- Chen, Z.; Zhou, Y.; Zhang, L.; Lin, C.; Huang, Y.; Tang, S. Ground Moving Target Imaging and Analysis for Near-Space Hypersonic Vehicle-Borne Synthetic Aperture Radar System with Squint Angle. Remote Sens. 2018, 10, 1966. [Google Scholar] [CrossRef] [Green Version]
- Wang, Y.; Cao, Y.; Wang, S.; Su, H. Clutter suppression and ground moving target imaging approach for hypersonic vehicle borne multichannel radar based on two-step focusing method. Digit. Signal Process. 2019, 85, 62–76. [Google Scholar] [CrossRef]
- Rybak, J.P.; Churchill, R.J. Progress in Reentry Communications. IEEE Trans. Aerosp. Electron. Syst. 1971, AES-7, 879–894. [Google Scholar] [CrossRef]
- Shao, C.; Nie, L.; Chen, W. Analysis of weakly ionized ablation plasma flows for a hypersonic vehicle. Aerosp. Sci. Technol. 2016, 51, 151–161. [Google Scholar] [CrossRef]
- Xie, K.; Yang, M.; Bai, B.; Li, X.; Zhou, H.; Guo, L. Re-entry communication through a plasma sheath using standing wave detection and adaptive data rate control. J. Appl. Phys. 2016, 119, 023301. [Google Scholar] [CrossRef]
- Li, L.; Wei, B.; Yang, Q.; Yang, X.; Ge, D. High-Order SO-DGTD Simulation of Radio Wave Propagation Through Inhomogeneous Weakly Ionized Dusty Plasma Sheath. IEEE Antennas Wirel. Propag. Lett. 2017, 16, 2078–2081. [Google Scholar] [CrossRef]
- Song, L.; Li, X.; Bai, B.; Liu, Y. Effects of Plasma Sheath on the Signal Detection of Narrowband Receiver. IEEE Trans. Plasma Sci. 2018, 47, 251–258. [Google Scholar] [CrossRef]
- Yao, B.; Li, X.; Shi, L.; Liu, Y.; Lei, F.; Zhu, C. Plasma sheath: An equivalent nonlinear mirror between electron density and transmitted electromagnetic signal. Phys. Plasmas 2017, 24, 102104. [Google Scholar] [CrossRef]
- Yao, B.; Li, X.; Shi, L.; Liu, Y.; Zhu, C. A Geometric-Stochastic Integrated Channel Model for Hypersonic Vehicle: A Physical Perspective. IEEE Trans. Veh. Technol. 2019, 68, 4328–4341. [Google Scholar] [CrossRef]
- Zhang, Y.; Liu, Y.; Li, X. A 2-D FDTD Model for Analysis of Plane Wave Propagation Through the Reentry Plasma Sheath. IEEE Trans. Antennas Propag. 2017, 65, 5940–5948. [Google Scholar] [CrossRef]
- Bai, B.; Li, X.; Liu, Y.; Xu, J.; Shi, L.; Xie, K. Effects of Reentry Plasma Sheath on the Polarization Properties of Obliquely Incident EM Waves. IEEE Trans. Plasma Sci. 2014, 42, 3365–3372. [Google Scholar] [CrossRef]
- Liu, Z.; Bao, W.; Li, X.; Liu, D.; Bai, B. Effects of Pressure Variation on Polarization Properties of Obliquely Incident RF Waves in Re-Entry Plasma Sheath. IEEE Trans. Plasma Sci. 2015, 43, 3147–3154. [Google Scholar] [CrossRef]
- Liu, H.; Liu, Y.; Yang, M.; Li, X. A Joint Demodulation and Estimation Algorithm for Plasma Sheath Channel: Extract Principal Curves with Deep Learning. IEEE Wirel. Commun. Lett. 2019, 9, 433–437. [Google Scholar] [CrossRef]
- Yang, M.; Li, X.; Wang, D.; Liu, Y.; He, P. Propagation of phase modulation signals in time-varying plasma. AIP Adv. 2016, 6, 055110. [Google Scholar] [CrossRef] [Green Version]
- Chen, X.-Y.; Li, K.-X.; Liu, Y.-Y.; Zhou, Y.-G.; Li, X.-P. Study of the influence of time-varying plasma sheath on radar echo signal. IEEE Trans. Plasma Sci. 2017, 45, 3166–3176. [Google Scholar] [CrossRef]
- Ding, Y.; Bai, B.; Gao, H.; Liu, Y.; Li, X.; Zhao, M. Method of Detecting a Target Enveloped by a Plasma Sheath Based on Doppler Frequency Compensation. IEEE Trans. Plasma Sci. 2020, 48, 4103–4111. [Google Scholar] [CrossRef]
- Bian, Z.; Li, J.; Guo, L. Simulation and Feature Extraction of the Dynamic Electromagnetic Scattering of a Hypersonic Vehicle Covered with Plasma Sheath. Remote Sens. 2020, 12, 2740. [Google Scholar] [CrossRef]
- Ren, Y.; Guo, L.; Chen, W.; Liu, S. Analysis of the electromagnetic scattering characteristics in two-dimensional time-varying and spatially non-uniform plasma sheath. Phys. Plasmas 2019, 24, 093515. [Google Scholar] [CrossRef]
- Sha, Y.-X.; Zhang, H.-L.; Guo, X.; Xia, M.-Y. Analyses of Electromagnetic Properties of a Hypersonic Object with Plasma Sheath. IEEE Trans. Antennas Propag. 2019, 67, 2470–2481. [Google Scholar] [CrossRef]
- Zheng, B.; Jiangting, L.; Lixin, G.; Xi, L. Range Profile Analysis of Hypersonic Vehicles Covered by Inhomogeneous Plasma Sheath Using Physical Optics. IEEE Trans. Plasma Sci. 2019, 47, 4961–4970. [Google Scholar] [CrossRef]
Parameters | Value |
---|---|
Pulse width | 40 μs |
Bandwidth | 120 MHz |
Carrier frequency | 10.5 GHz |
PRF | 7460 Hz |
Platform velocity | 7000 m/s |
Elevation angle | 35° |
Collision frequency | 4 GHz |
SNR | 15 dB |
Parameters | Value |
---|---|
Pulse width | 40 μs |
Bandwidth | 120 MHz |
PRF | 7460 Hz |
Platform velocity | 7000 m/s |
Elevation angle | 30° |
Collision frequency | 4 GHz |
SNR | 10 dB |
Parameters | Value |
---|---|
Pulse width | 40 μs |
Bandwidth | 120 MHz |
PRF | 7460 Hz |
Platform velocity | 7000 m/s |
Elevation angle | 30° |
Peak electron density | 5 × 1017/m3 |
SNR | 10 dB |
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Song, L.; Bai, B.; Li, X.; Niu, G.; Liu, Y.; Zhao, L.; Zhou, H. Analysis of Hypersonic Platform-Borne SAR Imaging: A Physical Perspective. Remote Sens. 2021, 13, 4943. https://doi.org/10.3390/rs13234943
Song L, Bai B, Li X, Niu G, Liu Y, Zhao L, Zhou H. Analysis of Hypersonic Platform-Borne SAR Imaging: A Physical Perspective. Remote Sensing. 2021; 13(23):4943. https://doi.org/10.3390/rs13234943
Chicago/Turabian StyleSong, Lihao, Bowen Bai, Xiaoping Li, Gezhao Niu, Yanming Liu, Liang Zhao, and Hui Zhou. 2021. "Analysis of Hypersonic Platform-Borne SAR Imaging: A Physical Perspective" Remote Sensing 13, no. 23: 4943. https://doi.org/10.3390/rs13234943