Core Journal of Peking University

Excellent Sci-Tech Journal of Chinese Universities

Journal of Committee of Deep Space Exploration Technology, Chinese Society of Astronautics(CDSET-CSA)

Advanced Search


Articles prepublish have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
Bouncing Motion and Path Planning of Small Body Surface Rover
WANG Bang, XU Rui, LI Zhaoyu, GAO Yue
 doi: 10.15982/j.issn.2096-9287.2022.20220042
To address the problem that wheeled mobile rovers are difficult to adapt to the surface environment of small bodies. The jumping mode of the rover with cubic configuration is analyzed. A single-step bouncing strategy is proposed to exploit its barrier-crossing capability. At the same time, a variable-step A* algorithm is proposed to plan the surface movement path of the rover. The simulation results show that the rover can effectively cross the obstacles. The new algorithm reduces the path nodes and is more efficient for high-density obstacle terrain.
Design of Terrain Dynamic Simulation and Landing View Simulation System for Small Celestial Bodies
YAO Wenlong, LIU Yi, SHAO Wei, SUN Yujie
 doi: 10.15982/j.issn.2096-9287.2022.20220010
Aiming at the problem that it is difficult to carry out experimental verification for optical image navigation of small celestial body detector landing section, a small celestial body terrain dynamic simulation and landing scene simulation system is designed based on virtual reality, and the detector attitude design and landing sequence image acquisition are realized. The small celestial body model is established by using three-dimensional modeling technology, and the weighted least square method is used to realize the smooth grid of the model; Linear interpolation is used to process the map, and texture mapping is realized by combining spherical mapping with cube mapping; The virtual scene simulation is developed, and the detector attitude design is realized according to the rotation matrix method. Experiments show that the simulation system can meet the demand for image navigation verification of the landing section of the probe, and can realize dynamic observation of small object topography and landing image acquisition with high graphic quality and good real-time performance, and the effectiveness of the system is verified by specific example simulation.
Navigation and Orbit Determination Performance Analysis of the Russian Space System “NEBOSVOD” for Monitoring Near Earth Objects
GUO Peng, IVASHKIN V V, LANG Anqi, CHEN Xianggui, CUI Hutao
 doi: 10.15982/j.issn.2096-9287.2022.20220045
This paper analyzes and evaluates the navigation and orbit determination performance of the Russian space system "NEBOCVOD", which is designed for monitoring Near Earth Objects (NEOs). And we focus on the optical detectable region and asteroid orbit determination accuracy of the system. Firstly, considering the features of space-based optical measurement system, we propose a method for analyzing the optical detectable region by constructing the contours of apparent magnitude and the apparent motion trajectory of asteroids in the Sun-Earth rotating coordinate system. Then, by modeling the motion and measurement of the system, and considering the influence of uncertain nuisance parameters, we propose a novel approach for orbit determination and accuracy analysis based on improved least square method and covariance analysis. Finally, taking the hazardous NEOs (Apophis, 2008TC3 and Chelyabinsk meteorite) as examples, we simulate the observation and orbit determination process when the "NEBOSVOD" system is assumed to monitor NEOs with different orbital types and sizes, and present the simulation results for multiple measurement intervals. It is shown that the "NEBOCVOD" system can effectively observe medium-sized asteroids like Apophis (D≈320 m) and smaller (D≈4-50 m) NEOs, including those approaching Earth from the Sun, and can achieve high enough navigation and orbit determination accuracy. Our methods and results may provide help for the design and research of the similar space-based monitoring system.
Dynamics of Resonant Orbits in the Irregular Gravitational Field of a Binary Asteroid System
CUI Shuhao, WANG Ye, ZHANG Ruikang
 doi: 10.15982/j.issn.2096-9287.2022.20220024
By taking the binary system 66391 Moshup as an example, this paper applies a polyhedron-ellipsoid model to study the dynamics of resonant orbits nearby the binary system. A series of resonant orbital families are calculated by the shooting method and continuation method, and the stability and bifurcation of the orbital families are analyzed. Finally, homoclinic connections between resonant orbits are computed by using invariant manifolds. The research shows that no strictly planar resonant orbit exists because of the asymmetry of the gravitational field, and the orbital stability and bifurcation have also been affected. In addition, the availability of designing transfer trajectories through resonant orbits is also demonstrated.
Robust Landmark Matching Method for Visual Navigation Near Small Bodies
HU Ronghai, HUANG Xiangyu, XU Chao
 doi: 10.15982/j.issn.2096-9287.2022.20220019
Robust and accurate landmark matching results can provide the probe with its global positioning information, which is one of the enabling technologies to achieve autonomous navigation. A robust and efficient landmark matching algorithm is proposed in this paper to deal with the extreme environment near the target asteroid. First, the matching error of the landmark generated by the SPC (StereoPhotoClinometry) technology is analyzed, and the influence of landmark position error and cameras’ pose error on the matching results is discussed. Then, based on the error analysis, the optimal landmark points are selected, and a weighted normalized cross-correlation (WNCC) algorithm is proposed to obtain accurate matching results robustly and efficiently. Finally, high-fidelity synthetic image sequences are generated to compare the performance of WNCC and the widely used NCC (Normalized Cross-Correlation) algorithm in the previous asteroid missions under a wide range of image scales, viewing geometries, and lighting conditions. The numerical results demonstrate the advance of the proposed method in terms of efficiency, robustness, and accuracy.
Autonomous Navigation and Guidance for Asteroid Kinetic Impact Mission
HUANG Xiangyu, XU Chao, HU Ronghai, GUO Minwen
According to the requirements of near-Earth Asteroid kinetic impact mission, an autonomous GNC scheme is proposed, which contains the high-precision extraction method for the line of sight (LOS) of the asteroid center, high-precision autonomous relative navigation based on LOS measurement of the asteroid center, and iterative prediction guidance method. In this scheme, the LOS measurement of the asteroid center is used to estimate the relative position and velocity between the impactor and the asteroid in the direction perpendicular to the LOS. Although the elative position and velocity errors along the LOS are not estimated, the high-precision impact can be realized by the iterative prediction guidance method. The mathematical simulation shows that the proposed scheme can ensure the impactor to hit a near-Earth asteroid with the diameter 50 meter, the impact accuracy is better than 4 meter, which meets the mission requirements.
Deep Learning Prediction Frame Matching Algorithm of Small Celestial Navigation Landmarks
XIAO Yang, LI Shuai, WANG Guangze, SHAO Wei, YAO Wenlong
Deep learning algorithm has a higher recognition rate for navigation landmarks such as small meteor craters than traditional algorithms, but it is difficult to achieve matching under various image changes. To solve this problem, a description method of recognition prediction box based on feature descriptor is proposed, and the matching of recognition results is completed. Firstly, the circular support region of the recognition prediction frame was determined, and a 10-dimensional feature descriptor with rotation and translation, scale and luminance invariance was constructed, and the prediction frame was matched by the relative distance between the descriptor vectors. The results show that the proposed algorithm is robust to images under different transformations, and the correct matching rate of the prediction frame is over 90%. It will provide the reference for the asteroid exploration navigation system.
Integrated Design Method of Laser Topographic Mapping and Navigation of Small Celestial Body
GUO Shaogang, LI Lin, ZHU Feihu, WANG Li, ZHANG Yunfang, ZHAO Qin, ZHENG Yan, MA Yuechao, ZHANG Hengkang
 doi: 10.15982/j.issn.2096-9287.2022.20220041
Aiming at the requirements of high frame rate, high resolution and high ranging accuracy in small celestial body detection, the characteristics of laser detection technology is deeply analyzed, and a hybrid solid-state laser 3D terrain mapping and navigation integrated design method is proposed. high imaging frame rate is realized by single photon array device and 532nm fiber laser, large field of view and sub-pixel resolution are realized by multi-mode scanning of two-dimensional voice coil motor fast mirror, and high-precision beam expansion and diffraction of laser beam are realized by Damman grating beam splitter. The results show that the laser ranging accuracy is better than 3 cm (3-sigma), the frame rate is 4 Hz, and the imaging resolution is as high as 1 100×1 100. The proposed method can give consideration to topographic mapping and navigation, realize muti-function, light and miniaturized design, and greatly reduce resource consumption. It has good guiding significance for the implementation of small celestial body exploration missions.
Deep Neural Network Approximation of the Asteroid Polyhedron Model
Ni Yang, Pan Binfeng
In this paper, based on the polyhedral model of irregular asteroids, the gravity calculation and position judgment criteria of irregular asteroids are studied and approximated by using Deep neural network(DNN), and a fast calculation method for the unpowered descent mission of asteroids is proposed. The polyhedron method is used to generate training data, and two DNN models are trained to calculate the gravitational field around the asteroid and judge whether it reaches the asteroid boundary. This method can not only ensure the accuracy of gravity calculation near asteroids, but also save calculation time. Taking Eros 433 asteroid as an example, the trajectory and impact point position of the unpowered descent process are simulated. The simulation results show that the calculation accuracy of the DNN model can meet the mission requirements, the deviation of the impact point position is within a reasonable range, and the calculation efficiency is high, which can be used in large-scale simulation experiments.
Analysis and Evaluation of Mapping Orbits in the Vicinity of Co-orbital Asteroids
SHI Yu, SHU Leizheng, ZHANG Hao
 doi: 10.15982/j.issn.2096-9287.2022.20220044
During the asteroid exploration missions, spacecrafts need to make an investigation of the characteristics of the asteroid after the approaching. This paper evaluates the performance of the fly-around mapping orbits and flyby mapping orbits. The stable fly-around orbits and hyperbolic flyby orbits at different distance are analyzed using numerical methods. A method to calculate the coverage rate of the orbits is proposed considering the sunlit condition and topographical shading. Then mapping orbits are analyzed in the perspective of coverage rate, mapping time, fuel cost and robustness. Taking nearly spherical asteroid 101955 Bennu and elongated asteroid 433 Eros as examples, the performance of the fly-around orbits and flyby orbits are evaluated, which will provide reference for the mapping phase in the future asteroid exploration.
Articles just accepted have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
Trajectory Optimization Design for Multiple-Target Asteroid Flyby Mission in Ecliptic Plane
HAO Zhixin, ZHENG Jianhua, LI Mingtao
 doi: 10.15982/j.issn.2096-9287.2022.20210143

Closely flying by asteroids can help to capture asteroid surface images, measure asteroid spectra, and obtain physical and chemical properties of asteroids. In particular, flying by multiple asteroids with potential hazards to the earth in one mission will significantly improve the understanding of the characteristics of potentially hazardous asteroids, and it is also of great significance to asteroid defense missions. In this paper, the trajectory for the multiple asteroid flyby mission of potentially hazardous asteroids was optimized. Firstly, the time and position distribution of asteroids passing through the ecliptic plane were analyzed, and the basic strategy of asteroids flyby in the ecliptic was determined. The time of asteroids crossing the ecliptic was taken as the time of asteroids’ flyby. Secondly, the sequential flyby sequence was optimized via beam selection tree search algorithm, and an optimization model for fast and effective solution of asteroid sequential flyby mission trajectory was established. The simulation results show that missions launched from 2024 to 2028 can fly by at least 18 potentially hazardous asteroids, especially the launch window in September 2027 which can fly by 21 potentially hazardous asteroids within a ten-year mission duration.

2022 Vol.9 No.3 Content
Online Preview
2022, 9(3).  
Abstract(127) PDF 18563KB(14)
The Solar Wind and Particle Radiation Environment on the Surface of the Moon—New Observations from Chang’E-4
WANG Chi, LI Lei, ZHANG Aibing, ZHANG Shenyi, HOU Donghui, XU Zigong, XIE Lianghai, WANG Huizi, LUO Pengwei, GUO Jingnan, SHI Quanqi, ZHANG Xiaoping
2022, 9(3): 239-249.   doi: 10.15982/j.issn.2096-9287.2022.20220020
Abstract(72) HTML(24) PDF 4710KB(31)
The solar wind, solar energetic particles and the galactic cosmic rays can reach the Moon almost unhindered, and interact with the lunar surface. The solar wind is partly scattered by the lunar regolith as hydrogen energetic neutral atoms, and the solar wind can also sputter heavy energetic neutral atoms out of the lunar regolith as well. While the albedo radiation, resulting from impact of the solar energetic particles and the galactic cosmic rays on the lunar regolith, are mainly composed of neutrons and gamma rays, features of the lunar surface radiation environment. The first ever in situ measurements of energetic neutral atoms and particle radiation have been carried out by Chang’E-4 on the lunar farside. Results reveal that a mini-magnetosphere is formed in the vicinity of the Moon, suggesting ENA is a new perspective to study the solar wind - Moon interaction. While the radiation measurements provide valuable information to guarantee the health of future robotic or manned missions to the Moon.
Topic:Moon-based Earth Observation (Guest Editor:Professor Guo Huadong, Aerospace Information Research Institute, Chinese Academy of Sciences)
Research Status and Prospect of Moon-Based Earth Observation: A Review
GUO Huadong, DING Yixing, LIU Guang
2022, 9(3): 250-260.   doi: 10.15982/j.issn.2096-9287.2022.20210080
Abstract(235) HTML(61) PDF 1756KB(60)
The deployment of remote sensing sensors on the Moon can realize long-term, overall and stable Earth observation and improve the observation ability of the existing system. In particular, from the outside of the Earth system, the Moon-based remote sensors can observe the evolution process of the earth system and the interaction and influence between the earth system and its exterior. This paper discusses the research progress of Moon-based earth observation in detail from four aspects: scientific objectives, sensor technology, parameter simulation and estimation methods and observatory location. The key scientific problems are analyzed, and a series of new models and methods are summarized. At the end of this paper, some suggestions for the development of Moon-based Earth observation are put forward.
Research on Spatio-Temporal Characteristics of Moon-Based SAR Earth Observation
CHEN Guoqiang, GUO Huadong, LIANG Da, DING Yixing, LV Mingyang, LIU Guang
2022, 9(3): 261-268.   doi: 10.15982/j.issn.2096-9287.2022.20210076
Abstract(95) HTML(25) PDF 3394KB(19)
With the rapid development of lunar exploration, the concept of moon-based observation of earth has received more and more attention. The synthetic aperture radar (SAR) deployed on the moon for earth observation can obtain continuous observations of large areas on earth surface, and realize a single wide-area observation mode which makes up for the deficiency of space-borne SAR. Based on the JPL ephemeris data, in this paper the observation difference of moon-based SAR in different scenarios such as time domain and space domain was analyzed, and the simulation of SAR echo was completed using the actual earth-moon spatial relationship. The results show that the moon-based SAR can always find the intersection line of zero Doppler plane on earth surface, and long-term, large-scale periodic observations can be achieved. The SAR echo simulation verifies its feasibility. The study of moon-based SAR observations can provide a basis for follow-up studies such as surface tidal movement and polar sea ice rebound.
Simulation and Application of Moon-Based Earth Observation Image
DENG Yu, GUO Huadong, LIU Guang, YE Hanlin, HUANG Jing
2022, 9(3): 269-277.   doi: 10.15982/j.issn.2096-9287.2022.20210073
Abstract(152) HTML(23) PDF 2778KB(26)
To solve the problem that the existing simulation system only qualitatively describes the Moon-based observation image, an image simulation method based on rigorous imaging model for Moon-based platform was proposed, and the quantitative relationship between image point and object point was established. The method was applied to the simulation of observation geometric image and radiation energy image. Based on long-time series simulation results, the effect of lunar orbit on geometric images and radiation energy images was further analyzed and summarized. The results show that this image simulation method based on the rigorous imaging model is feasible, and accurately expresses the image characteristics that vary with the characteristics of the lunar orbit. This method lays a foundation for the application of Moon-based observation images, and has great significance for the subsequent parameter design of different types of Moon-based sensors.
Geometric Simulation of Earth’s Outgoing Radiation Viewed from a Moon-Based Platform
HUANG Jing, GUO Huadong, LIU Guang, DENG Yu
2022, 9(3): 278-284.   doi: 10.15982/j.issn.2096-9287.2022.20210078
Abstract(173) HTML(22) PDF 2738KB(29)
Due to the characteristics of integrity, multi-angle and long period, a Moon-based platform is expected to accurately estimate Earth outgoing radiation. To evaluate this platform’s capabilities, this paper established a one-to-one mapping algorithm based on the geometric relationship and used the Goddard Earth Observing System model version 5 (GEOS-5) data as model input to simulate Earth’s outgoing radiation viewed from a Moon-based platform, so as to learn about the regularity of Earth outgoing radiation viewed from the Moon-based platform. Results show that a Moon-based platform can cover about 178° both in latitudinal and longitudinal direction in one image, including the polar regions. The changing inclination of the orbit of the Moon gives a better observation condition for high latitude regions, and the viewing zenith angle in polar regions can reach to 60°. These results indicate the simulation method can effectively support the observation of Earth’s outgoing radiation observation and lay the foundation for future research.
Characteristics Analysis of Moon-Based Monitoring of Earth’s Outgoing Radiation at the Top of Atmosphere
YE Hanlin, DENG Yu, LIU Guang, GUO Huadong
2022, 9(3): 285-291.   doi: 10.15982/j.issn.2096-9287.2022.20210074
Abstract(278) HTML(61) PDF 2819KB(61)
Due to the uncertainty of parameter design of the Moon-based radiometer, the characteristics of Moon-based Earth’s outgoing radiation at the top of the atmosphere were investigated. Based on the single-point observation geometry for a Moon-based platform, this paper analyzed observational characteristics and data of different Moon-based platforms’ positions on the lunar surface, and the observational sampling characteristics. The results indicate that the orbit of the Moon is with variable orbital inclination and variant observation distances from the Earth, and equipping a radiometer on the lunar surface can sample the whole Earth’s surface within one orbital period. In addition, the suggested dynamic range is from 5.50×10−2 to 8.50×10−2 W/m2, its temporal sampling interval is no more than 4 hours, and the accumulative sampling period is one orbital period (27.3 days). The above results provide an important basis for the design of the Moon-based radiometer.
Potential Moon-Based Platform Sites of Lunar South Polar Regions
ZHANG Jidong, LI Xiangyue, PING Jinsong
2022, 9(3): 292-299.   doi: 10.15982/j.issn.2096-9287.2022.20210079
Abstract(118) HTML(21) PDF 2674KB(26)
To select a suitable location for a Moon-based platform in the lunar south polar regions, the surface illumination, the Earth observation conditions and the slope are schosen as the main factors , which shows the solar energy and thermal environment on the lunar surface, the ability to obtain scientific data, and difficulty of construction. Based on the topography data and the orbit data of the Sun, the Earth and the Moon, an integrated solar illumination and Earth observation geometric model is established and applied to study seven key areas (M1 ~ M7). The lunar surface positions with the illumination rate greater than 80% and the Earth observation rate greater than 30% are taken as the primary selection area of the Moon-based platform, next, their slope conditions are analyzed and a grading evaluation is carried out. Combined with the characteristics of each primary selected area, three lunar positions with higher optimization level are finally recommended, which are located at the eastern edge of De Gerlache crater (in M1), the mountaintop where Sverdrup crater connects with Shackleton crater (in M4), and the mountaintop between the Shackleton crater and the Slater crater (in M7), and these results will provide reference for the follow-up lunar south polar exploration missions.
Topic:Mapping technique of extraterrestrial planets
Recent Advances and Prospects in Extraterrestrial Planets Mapping
XU Qing, GENG Xun
2022, 9(3): 300-310.   doi: 10.15982/j.issn.2096-9287.2022.20210162
Abstract(100) HTML(15) PDF 2114KB(22)
The topographic mapping of extraterrestrial planets provide basic geospatial data for engineering missions and various planetary scientific research, which can be used to select landing sites, plan path of rovers and conduct planetary geological and geomorphological analysis. We summarize the representative topographic mapping techniques and products in the exploration missions of moon, Mars and asteroids. This paper focuses on the research status of the techniques of generating digital orthophoto map and digital elevation model using mapping camera and LiDAR. We also give some suggestions on standard setting, data sharing, key technical bottlenecks and data processing technology system of extraterrestrial planets mapping.
A Low-resolution Slope Compensation Method Involving Slope Change Rate
YIN Li, YE Lejia, DI Kaichang, LIU Bin, SUN Xiaozhu, WANG Changhuan, BO Zheng
2022, 9(3): 311-320.   doi: 10.15982/j.issn.2096-9287.2022.20210161
Abstract(96) HTML(18) PDF 2945KB(9)
To solve the problem of slope reduction caused by the lack of high-resolution Digital Elevation Model ( DEM ) on the surface of moon, Mars and other planets, we propose a low-resolution slope compensation method involving slope change rate factors. It is an improvement on the existing linear compensation method by incorporating slope change rate into the compensation model to obtain better accuracy for slope compensation. In this paper, lunar and Martian data are used to verify the method. Several lunar and Martian low-resolution DEMs covering a variety of terrains are selected and compensated using the improved method. Then they are validated using slopes generated from the high-resolution DEMs. The results show that after applying the proposed compensation function, the compensated slopes can represent the terrain features of the lunar and Martian surface better compared to the original low-resolution slopes. Meanwhile, the proposed method considering the slope change rate is more effective than the traditional linear compensation method. Based on the improved method, the overall and hierarchical compensation models suitable for various lunar landforms are established and the low-resolution Martian slope data covering 50 km×50 km of the Tianwen-1 landing site are compensated and analyzed.
Study on Morphological Characteristics and Genesis of Dome Around Chang’E-5 Sampling Point
WU Wenhui, REN Xin, CHEN Yuan, Paliguli·JIEENSI, SUN Guoyang
2022, 9(3): 321-328.   doi: 10.15982/j.issn.2096-9287.2022.20210068
Abstract(246) HTML(39) PDF 3599KB(20)
Mons Rümker and Mairan volcanic dome structure are distributed around Chang’E-5 sampling point. At present, there is a lack of comparative research on their morphological characteristics, genesis and classification standards. Therefore, this paper compared the morphological characteristics and formation factors of the two types of domes through Chang’E image and topographic data, and discussed the division criteria of domes. In this study, 13 lunar mare domes of Mons Rümker and 4 non-mare domes of Mairan were delineated, and the magma rheological parameters during the formation of the domes were calculated. The results show that the Rümker lunar mare domes are relatively low and flat. According to the slope and height, the domes are divided into Rümker type I lunar mare dome (slope < 5 °, height 200-400 m) and Rümker type II mare dome (slope 5 °-7 °, height 300-600 m). Among them, the second kind of higher and steeper lunar sea dome has higher viscosity and lower eruption rate. Compared with the Rümker mare dome, the Mairan non-mare dome is higher and steeper, and its magma eruption rate is generally lower than that of mare domes, with high magma viscosity, poor fluidity and long eruption cycle. Spatially, the four non-lunar mare domes where Mairan is located are linearly distributed and their material composition and formation time are similar, indicating that they are likely to be related to each other.
Martian Landing Area Morphology Interpretation and Quantitative Analysis of the Zhurong Rover
LIU Jia, LIU Bin, DI Kaichang, YUE Zongyu, YU Tianyi, WANG Jia, GOU Sheng
2022, 9(3): 329-337.   doi: 10.15982/j.issn.2096-9287.2022.20210123
Abstract(97) HTML(15) PDF 5951KB(22)
Tianwen-1 lander and rover successfully landed in the southern Utopia Planitia of Mars on May 15, 2021. As China's first Mars exploration mission, Tianwen-1 achieved orbiting, landing and patrolling tasks in one mission. In this paper, we apply the photogrammetry methods to produce mapping products from high-resolution orbiter remote sensing images, and to analyze the landing area environment. The environment of the landing area is not only important for the path planning and safe driving of the Mars rover, but also provides fundamental information for science research. Mainly focuses on the Tianwen-1 landing area (within the surrounding 20 km of the landing point), and utilizes the 5 m/pixel CTX DOM and Tianwen-1 DEM product data to quantitatively analysis the impact crater density, impact crater depth, depth-to-diameter ratio, etc. Further interpretation and analysis of the geomorphic feature and geological background of the landing area are conducted. The results show that there are many small craters, transverse aeolian ridge, pitted cones, structural ridges and throughs in the region, most of the impact craters on the surface of the landing area are secondary craters or degraded impact craters, with an aspect ratio between 0.001 to 0.136. In addition to in-depth analysis of the geological and geomorphological features of the landing area, the crater statistics and geomorphic feature analysis are valuable for geological evolution study of the Utopia Planitia.
Topography Modeling, Mapping and Analysis of China’s First Mars Mission Tianwen-1 Landing Area from Remote Sensing Images
LIU Sicong, TONG Xiaohua, LIU Shijie, XIE Huan, ZHAO Hui, LIU Dayong, XU Xiong, YE Zhen, WANG Chao, LIU Xianglei
2022, 9(3): 338-347.   doi: 10.15982/j.issn.2096-9287.2022.20220005
Abstract(375) HTML(94) PDF 14972KB(42)
By using multi-source remote sensing image data from Mars Orbiters, the technical framework for Martian surface topography fine 3D modeling and automatic classification was developed. The high-resolution terrain of Tianwen-1 landing area was made by combining the photogrammetry and the Shape-from-Shading (SFS) methods, and high-resolution images were used to classify and analyze the topography category and distribution of the land area using a deep convolution neural network. The profile analysis results show that the high-precision terrain data presented in this paper are highly consistent with high resolution digital elevation model (DEM) products published by China and US, resulting in the mean elevation errors equal to 1.866 m and 1.074 m, respectively. Furthermore, it can be seen from the comprehensive terrain and morphology analysis by using the orbiter remote sensing images that near the landing point the slope is less than 3° and the fluctuation of the surface is less than 30 cm. This indicates that the overall terrain of Tianwen-1 landing area is flat and the morphology category is relatively single, which meets the requirements of the probe’s safe landing. The terrain produced by Tianwen-1 high-resolution camera data and classification results, which can be effectively applied to the morphological analysis of the landing and patrol areas, when combined with multi-source Mars remote sensing data such as HiRISE, can provide important basic data and reference information for subsequent scientific explorations of Zhurong patrol.
A Fast Photogrammetric Processing Method for Linear Pushbroom Planetary Remote Sensing Images
GENG Xun, XU Qing
2022, 9(3): 348-356.   doi: 10.15982/j.issn.2096-9287.2022.20210002
Abstract(70) HTML(23) PDF 3715KB(10)
Planetary photogrammetry is widely used to derive the mapping products of extraterrestrial planets. However, the existing planetary photogrammetric methods exhibit low efficiency and poor applicability for long strip linear pushbroom planetary images. We developed photogrammetric processing method as well as corresponding software modules for linear pushbroom planetary images based on fast geometric rectification. Based on the rigorous sensor model of linear pushbroom planetary images, the fast back projection algorithm is used for orthophotos rectification, and multi-threaded programming technique is also used to further improve the computational efficiency. To derive control network for linear pushbroom planetary images with large amount of data, we first conduct image matching on approximate orthophotos that derived from fast geometric rectification to acquire tie points, and then convert the matched tie points into original image space using rigorous sensor model. Experiments were conducted using Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) and Mars Express (MEX) Hight Resolution Stereo Camera (HRSC) images, and the corresponding DOMs and DEMs were derived. Compared with the planetary image processing software USGS ISIS, the developed method significantly improves the processing efficiency of linear pushbroom planetary images.

Founded in 2014, Bimonthly

Supervisor: Ministry of Industry and Information Technology

Sponsor: Beijing Institute of Technology, China Aerospace Society Committee for Deep Space Detection Technology

Editor-in-chief: Wu WeiRen

ISSN 2096-9287CN 10-1707/V

Address: 5 South Zhongguancun Street, Beijing

Telphone: (010)68915831 / 68915834