- 1Institute of Geology and Geophysics, Beijing, 100029, China, the Key Laboratory of Petroleum Resource Research, China (hetinghan@mail.iggcas.ac.cn)
- 2Institute of Geology and Geophysics, Beijing, 100029, China, the Key Laboratory of Petroleum Resource Research, China (wangyibo@mail.iggcas.ac.cn)
- 3Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing 314019, China(zhongshichao16@bit.edu.cn)
- 4Institute of Geology and Geophysics, Beijing, 100029, China, the Key Laboratory of Petroleum Resource Research, China (zhengyk@mail.iggcas.ac.cn)
- 5Institute of Geology and Geophysics, Beijing, 100029, China, the Key Laboratory of Petroleum Resource Research, China (lchen@mail.iggcas.ac.cn)
The Mars Rover Penetrating Radar (RoPeR), onboard China's Zhurong rover, has been employed to investigate Martian geological characteristics(Fig. 1.). However, challenges arise from the use of a 16° tilted monopole antenna and linear frequency modulation continuous wave (LFMCW) signals, which complicate data interpretation and reduce imaging accuracy for inclined subsurface structures. This study addresses these limitations by proposing a comprehensive approach combining radiation pattern compensation and forward modeling considering real transmit signals.
Fig. 1. RoPeR investigating Martian subsurface geology. The 16° tilted antenna, mounted at the front of the Zhurong Mars rover, transmits radar waves into the subsurface.
To simulate real conditions, we incorporated complex antenna models and LFMCW signals in forward modeling, revealing frequency-dependent radiation characteristics and hyperbolic echo tilting effects. The radiation patterns of horizontal and tilted monopole antennas were analyzed, focusing on their responses to scattering points and inclined interfaces.
Fig. 2. Radiation patterns of antennas. (a) Elevation pattern of a horizontal antenna at 55 MHz. (c) Elevation pattern of a tilted antenna.
Fig. 3.(a) Martian subsurface model with rocky blocks of different sizes in three layers. Horizontal (a) and tilted (b) monopole antennas' radargrams after background banding noise removal.
Numerical simulations and laboratory experiments revealed that traditional migration methods using omnidirectional antennas fail to adequately image inclined structures. To overcome this, a radiation-pattern-compensation reverse time migration (RPC-RTM) algorithm was developed using real RoPeR parameters (15–95 MHz LFMCW signals). This method employs an oppositely tilted antenna to propagate backward wavefields, achieving radiation pattern compensation and enhancing illumination for right-inclined structures. Compared to conventional methods, the proposed RPC-RTM and radiation-pattern-compensation back-propagation (RPCBP) algorithms significantly improve imaging quality by addressing radiation pattern limitations.
Fig. 4. (a)Zhurong Mars rover moving path. (b) is conventional RTM result with horizontal antenna. (c) is RPC-RTM image with opposite tilted antenna compensation. The left-inclined structures are more common marked with white circles in (b). The right-inclined structure appears marked with red circles in (c).
The proposed method was validated using simulated and laboratory data, demonstrating its effectiveness. Applied to RoPeR data, RPC-RTM successfully imaged right-inclined features and showed better adaptability to complex inhomogeneous models compared to traditional radiation pattern compensation methods. The results confirm that integrating realistic antenna models, LFMCW signals, and radiation pattern compensation enhances modeling accuracy and imaging quality.
Reference:
[1] Zhong, S.; Wang, Y.; Zheng, Y.; Chen, L, Radiation Pattern Compensation Reverse Time Migration of Zhurong Mars Rover Penetrating Radar, IEEE Transactions on Geoscience and Remote Sensing, 2024, 62. https://doi.org/10.1109/TGRS.2024.3350030.
[2] Zhong, S.; Wang, Y.; Zheng, Y.; Chen, L. Mars Rover Penetrating Radar Modeling and Interpretation Considering Linear Frequency Modulation Source and Tilted Antenna. Remote Sens. 2023, 15, 3423. https://doi.org/10.3390/rs15133423
How to cite: Han, H., Wang, Y., Zhong, S., Zheng, Y., and Chen, L.: Modeling and Radiation Pattern Compensation of Mars Rover Penetrating Radar with Tilted Antenna, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8102, https://doi.org/10.5194/egusphere-egu25-8102, 2025.
