# Near-Field IPO for Analysis of EM Scattering from Multiple Hybrid Dielectric and Conductor Target and High Resolution Range Profiles

^{1}

^{2}

^{*}

^{†}

## Abstract

**:**

## 1. Introduction

## 2. Methods

#### 2.1. Iterative Physical Optics

#### 2.2. Near-Field Correction

#### 2.3. Convergence Criterion

#### 2.4. Acceleration Strategy

## 3. Numerical Results

#### 3.1. Verification of the Method

#### 3.2. Scattering Characteristic of Hybrid Dielectric and Conductor Cube Target

#### 3.3. Scattering Characteristic of Missile-like Target

#### 3.4. Scattering Characteristic of Missile-like Target above Sea Surface

## 4. High Resolution Range Profiles

#### 4.1. HRRP Analysis of Missile-like Target

#### 4.2. HRRP Analysis of Different Pitch Angles

#### 4.3. HRRP Analysis of Different Azimuth Angles

#### 4.4. HRRP Analysis of Different Incident Frequency

#### 4.5. HRRP Analysis of Different Target Types

## 5. Discussion

#### 5.1. Scattering Characteristics

#### 5.2. HRRP Analysis

## 6. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

- Wang, R.; Guo, G.; He, Z.; Guo, L. Scattering Prediction of Target Above Layered Rough Surface Based on Time-Domain Ray Tracing Modeling. IEEE Trans. Antennas Propag.
**2020**, 69, 2820–2832. [Google Scholar] [CrossRef] - Zhu, G.; He, S.; He, J.; Xuezhi, W. Study of a 3DMLUV-FIA method for EM scattering from dielectric object and rough surface. In Proceedings of the 2016 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC), Cairns, QLD, Australia, 19–23 September 2016; pp. 122–125. [Google Scholar] [CrossRef]
- Corucci, L.; Giusti, E.; Martorella, M.; Berizzi, F. Near Field Physical Optics modelling for Concealed Weapon Detection. IEEE Trans. Antennas Propag.
**2012**, 60, 6052–6057. [Google Scholar] [CrossRef] - Rim, J.; Koh, I. Convergence and accuracy of near-field-corrected iterative physical optics for scattering by imperfectly conducting and dielectric objects. IET Microwaves, Antennas Propag.
**2020**, 14, 999–1005. [Google Scholar] [CrossRef] - Koh, I.-S.; Rim, J.-W.; Kim, W.-T. Application of IPO method to calculate scattering by conducting and dielectric objects. In Proceedings of the 2016 URSI Asia-Pacific Radio Science Conference (URSI AP-RASC), Seoul, Republic of Korea, 21–25 August 2016; pp. 1569–1571. [Google Scholar] [CrossRef]
- Habi, H.V.; Messer, H. Recurrent Neural Network for Rain Estimation Using Commercial Microwave Links. IEEE Trans. Geosci. Remote Sens.
**2020**, 59, 3672–3681. [Google Scholar] [CrossRef] - Cui, Y.; Chen, W.; Jia, Q.; Man, L.; Zhang, X. An Accurate Modeling Method for Near-field Echo Characteristics. In Proceedings of the 2019 Photonics & Electromagnetics Research Symposium-Fall (PIERS-Fall), Xiamen, China, 17–20 December 2019; pp. 1306–1311. [Google Scholar] [CrossRef]
- Sanchez-Olivares, P.; Lozano, L.; Somolinos, Á.; Cátedra, F. EM Modelling of Monostatic RCS for Different Complex Targets in the Near-Field Range: Experimental Evaluation for Traffic Applications. Electronics
**2020**, 9, 1890. [Google Scholar] [CrossRef] - Guo, G.; Guo, L. SBR Method for Near-Field Scattering of an Electrically Large Complex Target Illuminated by Dipole Sources. IEEE Access
**2018**, 6, 78710–78718. [Google Scholar] [CrossRef] - Qi, C.; Yang, W.; Zhu, X. Near-Field Electromagnetic Scatterings and Imaging of a Ship Based on High-Frequency Techniques. Int. J. Antennas Propag.
**2022**, 2022, 1–6. [Google Scholar] [CrossRef] - Bagheri-Korani, E.; Ahmadi-Boroujeni, M.; Mohammadpour-Aghdam, K. A procedure for the design of wideband slant-polarized shaped reflector antennas using a PO-based near field analysis method. In Proceedings of the 2015 Asia-Pacific Microwave Conference (APMC), Nanjing, China, 6–9 December 2015; pp. 1–3. [Google Scholar] [CrossRef]
- Sharma, S.; Patel, U.R.; Triverio, P. Accelerated Electromagnetic Analysis of Interconnects in Layered Media Using a Near-Field Series Expansion of the Green’s Function. In Proceedings of the 2018 IEEE 27th Conference on Electrical Performance of Electronic Packaging and Systems (EPEPS), San Jose, CA, USA, 14–17 October 2018; pp. 185–187. [Google Scholar] [CrossRef]
- Rim, J.-W.; Koh, I.-S. Derivation of Analytic Formulas and Numerical Verification of Weakly Singular Integrals for Near-Field Correction in Surface Integral Equations. J. Electromagn. Eng. Sci.
**2017**, 17, 91–97. [Google Scholar] [CrossRef] [Green Version] - Bourlier, C.; Kubicke, G.; Pouliguen, P. Accelerated Computation of the Physical Optics Approximation for Near-Field Single- and Double-Bounces Backscattering. IEEE Trans. Antennas Propag.
**2019**, 67, 7518–7527. [Google Scholar] [CrossRef] - Tian, G.; Tong, C.; Sun, H.; Zou, G.; Liu, H. Improved Hybrid Algorithm for Composite Scattering From Multiple 3D Objects Above a 2D Random Dielectric Rough Surface. IEEE Access
**2020**, 9, 4435–4446. [Google Scholar] [CrossRef] - Sui, M.; Xu, X. Near-field iterative physical optics based on distinct wave propagation vector. In Proceedings of the 2010 IEEE Antennas and Propagation Society International Symposium, Toronto, ON, Canada, 11–17 July 2010; pp. 1–4. [Google Scholar] [CrossRef]
- Wang, Q.; Tong, C.; Li, X.; Wang, Y.; Wang, Z.; Wang, T. Composite Electromagnetic Scattering and High-Resolution SAR Imaging of Multiple Targets above Rough Surface. Remote Sens.
**2022**, 14, 2910. [Google Scholar] [CrossRef] - Rim, J.-W.; Koh, I.-S. Accuracy Test of Iterative Physical Optics for Analyzing Scattering by Nonperfectly Conducting Bodies Using Impedance Boundary Conditions. In Proceedings of the 12th European Conference on Antennas and Propagation (EuCAP 2018), London, UK, 9–13 April 2018. [Google Scholar] [CrossRef]
- Chen, B.; Tong, C. Modified physical optics algorithm for near field scattering. Chin. Phys. B
**2018**, 27, 114102. [Google Scholar] [CrossRef] - Chen, B.; Tong, C. Near-field scattering evaluation based on improved PO and EECs. Electron. Lett.
**2019**, 55, 180–182. [Google Scholar] [CrossRef] - Burkholder, R.; Lundin, T. Forward-backward iterative physical optics algorithm for computing the RCS of open-ended cavities. IEEE Trans. Antennas Propag.
**2005**, 53, 793–799. [Google Scholar] [CrossRef]

**Figure 4.**Mono-static RCS for HH polarization of four hybrid dielectric and conductor cubes in free space.

**Figure 6.**Mono-static RCS for HH polarization of different numbers of hybrid dielectric and conductor cubes in free space.

**Figure 8.**Mono-static RCS for HH polarization of hybrid dielectric and conductor missile-like targets with different numbers in free space.

**Figure 9.**Mono-static RCS for HH polarization of hybrid dielectric and conductor missile-like targets with different distributions of position in free space.

**Figure 10.**Bistatic RCS for HH polarization of hybrid dielectric and conductor missile-like targets with different wind speeds above the sea surface.

**Figure 11.**The HRRP of hybrid dielectric and conductor missile-like targets with different distribution of positions in free space.

**Figure 12.**The HRRP of hybrid dielectric and conductor missile-like targets with different pitch angles in the free space.

**Figure 13.**The HRRP of hybrid dielectric and conductor missile-like targets with different azimuth angles in the free space.

**Figure 14.**The HRRP of hybrid dielectric and conductor missile-like targets with different incident frequency in the free space.

**Figure 15.**The geometry structure of different types of missile-like targets: (

**a**) type 1; (

**b**) type 2; (

**c**) type 3.

**Figure 16.**The HRRP of different types of hybrid dielectric and conductor missile-like targets in the free space.

Method | RAM | CPU Time (s) | RMSE |
---|---|---|---|

Proposed Method | 122.414 | 1700 | 1.8423 |

MLFMM Solver | 61.909 | 20,883 | 0.0000 |

Measured Data | ---- | ---- | 2.2556 |

Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Wang, Q.; Wang, Y.; Tong, C.; Wang, Z.; Li, X.; Wang, T.
Near-Field IPO for Analysis of EM Scattering from Multiple Hybrid Dielectric and Conductor Target and High Resolution Range Profiles. *Remote Sens.* **2023**, *15*, 1884.
https://doi.org/10.3390/rs15071884

**AMA Style**

Wang Q, Wang Y, Tong C, Wang Z, Li X, Wang T.
Near-Field IPO for Analysis of EM Scattering from Multiple Hybrid Dielectric and Conductor Target and High Resolution Range Profiles. *Remote Sensing*. 2023; 15(7):1884.
https://doi.org/10.3390/rs15071884

**Chicago/Turabian Style**

Wang, Qingkuan, Yijin Wang, Chuangming Tong, Zhaolong Wang, Ximin Li, and Tong Wang.
2023. "Near-Field IPO for Analysis of EM Scattering from Multiple Hybrid Dielectric and Conductor Target and High Resolution Range Profiles" *Remote Sensing* 15, no. 7: 1884.
https://doi.org/10.3390/rs15071884