Recent Progress of Earth Observation Satellites in China

Currently,China has 32 Earth observation satellites in orbit.The satellites can provide various data such as optical,multispectral,infrared,and radar.The spatial resolution of China Earth observation satellites ranges from low to medium to high.The satellites possess the capability to observe across multiple spectral bands,under all weather conditions,and at all times.The data of China Earth observation satellites has been widely used in fields such as natural resource detection,environmental monitoring and protection,disaster prevention and reduction,urban planning and mapping,agricultural and forestry surveys,land survey and geological prospecting,and ocean forecasting,achieving huge social benefits.This article introduces the recent progress of Earth observation satellites in China since 2022,especially the satellite operation,data archiving,data distribution and data coverage.

Improved algorithms to plan missions for agile earth observation satellites

This study concentrates of the new generation of the agile （AEOS）. AEOS is a key study object on management problems earth observation satellite in many countries because of its many advantages over non-agile satellites. Hence, the mission planning and scheduling of AEOS is a popular research problem. This research investigates AEOS characteristics and establishes a mission planning model based on the working principle and constraints of AEOS as per analysis. To solve the scheduling issue of AEOS, several improved algorithms are developed. Simulation results suggest that these algorithms are effective.

Conspiracy Determines World War III with Reference to Several Windows’ Channel in Connection with Earth Observation Satellite

Thermonuclear reaction exerts its influence of X-emission to produce several windows’ channel in the presence of an oscillator under electrical relay circuit with a decisive importance to a radiofrequency Earth observation satellite. Indian Television Network (National Channel) has introduced a radiofrequency accelerator to produce X-emission at resonance with an activation of artificial human environment under relay analogy in the presence of an Earth observation satellite. Thermonuclear reaction communicates several windows’ channel via Earth observation satellite. Star Television network communicates an artificial human environment under the influence of a relay circuit with different pulse code units of human brain with an active influence of an artificial sensation to generate the loss of humanity around the world.

Mission Planning and Action Planning for Agile Earth-Observing Satellite with Genetic Algorithm

This paper concerns the mission scheduling problem for an agile Earth-observing satellite. Mission planning and action planning for the satellite are both taking into account. Multiple mission types( including multi-strip area,real time download request,and stereoscopic request) and complex satellite actions,such as observe action and data download action,are considered in this paper. Through reasonable analysis of specialties and operational constraints of agile satellites in observing process,the mission scheduling model under multiple objective conditions is constructed. A genetic algorithm combined with heuristic rules is designed to solve problem. Genetic algorithm is designed to arrange user missions and heuristic rules are used to arrange satellite actions. Experiment results suggest that our algorithm works well for the agile Earth-observing satellite scheduling problem.

2012–2014 China's Earth Observation and Earth Science Development

Human beings are now facing global and regional sustainable development challenges.In China, Earth observation data play a fundamental role in Earth system science research. The support given by Earth observation data is required by many studies, including those on Earth's limited natural resources, the rapid development of economic and social needs, global change, extreme events, food security, water resources, sustainable economic and urban development, and emergency response. Application operation systems in many ministries and departments in China have entered a stage of sustainable development, and the State Key Project of High-Resolution Earth Observation Systems has been progressing since 2006. Earth observation technology in China has entered a period of rapid development.

Monitoring Wildfires in Thailand: A Case Study of the ECSTAR-TeroSpace’s Earth Observation Project

The primary objective of this paper is to present a comprehensive case study on monitoring wildfires in Nakhon Nayok, Thailand, utilizing Earth observation platforms. This initiative project has been undertaken by the Excellence Center of Space Technology and Research (ECSTAR), in partnership with its spin-off startup, TeroSpace. The study aims to provide an in-depth analysis of the wildfire incidents in the region, utilizing advanced technologies such as satellite imagery and data analytics, and to identify ways to improve future wildfire management. In particular, the paper focuses on the wildfires including thermal area comparison that ravaged the land in Nakhon Nayok Province in central Thailand from March to April 18th, 2023. To conduct this study, the ECSTAR-TeroSpace analytic team utilized satellite images from Earth observation platforms: MODIS and Sentinel-2A. By presenting this case study, this paper contributes to the broader understanding of how to monitor and manage wildfires in a changing climate. The findings of this study underscore the importance of proactive and collaborative efforts in mitigating the negative impacts of wildfires in Nakhon Nayok and other regions in Thailand.

GEOSatDB:global civil earth observation satellite semantic database

Satellite remote sensing,characterized by extensive coverage,fre-quent revisits,and continuous monitoring,provides essential data support for addressing global challenges.Over the past six decades,thousands of Earth observation satellites and sensors have been deployed worldwide.These valuable Earth observation assets are contributed independently by various nations and organizations employing diverse methodologies.This poses a significant challenge in effectively discovering global Earth observation resources and realizing their full potential.In this paper,we describe the develop-ment of GEOSatDB,the most complete semantic database of civil Earth observation satellites developed based on a unified ontology model.A similarity matching method is used to integrate satellite information and a prompt strategy is used to extract unstructured sensor information.The resulting semantic database contains 127,949 semantic statements for 2,340 remote sensing satellites and 1,021 observation sensors.The global Earth observation capabil-ities of 195 countries worldwide have been analyzed in detail,and a concrete use case along with an associated query demonstration is presented.This database provides significant value in effectively facilitating the semantic understanding and sharing of Earth observa-tion resources.

Distributed cooperative task planning algorithm for multiple satellites in delayed communication environment

Multiple earth observing satellites need to communicate with each other to observe plenty of targets on the Earth together. The factors, such as external interference, result in satellite information interaction delays, which is unable to ensure the integrity and timeliness of the information on decision making for satellites. And the optimization of the planning result is affected. Therefore, the effect of communication delay is considered during the multi-satel ite coordinating process. For this problem, firstly, a distributed cooperative optimization problem for multiple satellites in the delayed communication environment is formulized. Secondly, based on both the analysis of the temporal sequence of tasks in a single satellite and the dynamically decoupled characteristics of the multi-satellite system, the environment information of multi-satellite distributed cooperative optimization is constructed on the basis of the directed acyclic graph（DAG）. Then, both a cooperative optimization decision making framework and a model are built according to the decentralized partial observable Markov decision process（DEC-POMDP）. After that, a satellite coordinating strategy aimed at different conditions of communication delay is mainly analyzed, and a unified processing strategy on communication delay is designed. An approximate cooperative optimization algorithm based on simulated annealing is proposed. Finally, the effectiveness and robustness of the method presented in this paper are verified via the simulation.

Capability of Fengyun-3D Satellite in Earth System Observation

From the viewpoint of earth system science,this paper discusses the observation capability of the second-generation of Chinese polar-orbiting,sun-synchronous operational meteorological satellite observation systems,Fengyun-3(FY-3),based on the function and performance test results from the FY-3 D satellite observation system in orbit.The FY-3 series of satellites have numerous remote sensing instruments and a wide range of imaging and sounding electromagnetic spectrometers onboard.These instruments can obtain reflectivity data for land surface,soil,vegetation,water body,snow cover,ocean color,and sea ice on earth’s surface over a wide spectral range,as well as information on the absorption and scattering radiative transfer of molecules and particles(clouds and aerosols)in earth’s atmosphere.All of these data can be used to retrieve physical and chemical information about the land,ocean,and atmosphere of the earth system.Comprehensive observation of the earth system by the FY-3 meteorological satellites is preliminarily realized.

Current issues in high-resolution earth observation technology

This paper reviewed the developments of the last ten years in the field of international high-resolution earth observation, and introduced the developmental status and plans for China's high-resolution earth observation program. In addition, this paper expounded the transformation mechanism and procedure from earth observation data to geospatial information and geographical knowledge, and examined the key scientific and technological issues, including earth observation networks, high-precision image positioning, image understanding, automatic spatial information extraction, and focus services. These analyses provide a new impetus for pushing the application of China's high-resolution earth observation system from a "quantity" to "quality" change, from China to the world, from providing products to providing online service.

General modeling and optimization technique for real-world earth observation satellite scheduling

Over the last two decades,many modeling and optimization techniques have been developed for earth observation satellite(EOS)scheduling problems,but few of them show good generality to be engineered in realworld applications.This study proposes a general modeling and optimization technique for common and real-world EOS scheduling cases;it includes a decoupled framework,a general modeling method,and an easy-to-use algorithm library.In this technique,a framework that decouples the modeling,constraints,and optimization of EOS scheduling problems is built.With this framework,the EOS scheduling problems are appropriately modeled in a general manner,where the executable opportunity,another format of the well-known visible time window per EOS operation,is viewed as a selectable resource to be optimized.On this basis,10 types of optimization algorithms,such as Tabu search and genetic algorithm,and a parallel competitive memetic algorithm,are developed.For simplified EOS scheduling problems,the proposed technique shows better performance in applicability and effectiveness than the state-of-the-art algorithms.In addition,a complicatedly constrained real-world benchmark exampled by a four-EOS Chinese commercial constellation is provided,and the technique is qualified and outperforms the in-use scheduling system by more than 50%.

Agile Earth Observation Satellite Scheduling Algorithm for Emergency Tasks Based on Multiple Strategies

During the execution of imaging tasks,satellites are often required to observe natural disasters,local wars,and other emergencies,which regularly interferes with the execution of existing schemes.Thus,rapid satellite scheduling is urgently needed.As a new generation of three degree-of-freedom(roll,pitch,and yaw)satellites,agile earth observation satellites(AEOSs)have longer variable-pitch visible time windows for ground targets and are capable of observing at any time within the time windows.Thus,they are very suitable for emergency tasks.However,current task scheduling models and algorithms ignore the time,storage and energy consumed by pitch.Thus,these cannot make full use of the AEOS capabilities to optimize the scheduling for emergency tasks.In this study,we present a fine scheduling model and algorithm to realize the AEOS scheduling for emergency tasks.First,a novel time window division method is proposed to convert a variable-pitch visible time window to multiple fixed-pitch visible time windows.Second,a model that considers flexible pitch and roll capabilities is designed.Finally,a scheduling algorithm based on merging insertion,direct insertion,shifting insertion,deleting insertion,and reinsertion strategies is proposed to solve conflicting problems quickly.To verify the effectiveness of the algorithm,48 groups of comparative experiments are carried out.The experimental results show that the model and algorithm can improve the emergency task completion efficiency of AEOSs and reduce the disturbance measure of the scheme.Furthermore,the proposed method can support hybrid satellite resource scheduling for emergency tasks.

Solving the Observing and Downloading Integrated Scheduling Problem of Earth Observation Satellite with a Quantum Genetic Algorithm

This paper addresses the integrated Earth observation satellite scheduling problem. It is a complicated problem because observing and downloading operations are both involved. We use an acyclic directed graph model to describe the observing and downloading integrated scheduling problem.Based on the model which considering energy constraints and storage capacity constraints, we develop an efficient solving method using a novel quantum genetic algorithm. We design a new encoding and decoding scheme that can generate feasible solution and increase the diversity of the population.The results of the simulation experiments show that the proposed method solves the integrated Earth observation satellite scheduling problem with good performance and outperforms the genetic algorithm and greedy algorithm on all instances.

Optimization of earth observation satellite system based on parallel systems and computational experiments

Earth observation satellite system （EOSS） is the main space platform to collect ground information. Op- timization of EOSS is still a difficult problem, as it is a complex system concerning a great deal of design variables and uncertain factors. To solve the problem, an optimization framework based on parallel system and computational experi- ments is proposed. An artificial system for EOSS is firstly constructed, which is the integration of resource data, task data, environment data and related operation rules. Real EOSS together with artificial EOSS constitute the parallel systems for EOSS. Based on the parallel systems, concept of computational experiments is detailed. Moreover, surrogate models are built to approximate real EOSS. Genetic algorithm and improved general pattern search method are adopted to optimize the model. According to the framework, a case study is carried out. Through the results, we illustrated the proposed framework to be useful and effective for EOSS optimization problem.

The application of China’s land observation satellites within the framework of Digital Earth and its key technologies

Digital Earth is an interdisciplinary field involving space technology,information technology,and geoscience.This article introduces the land observation satellite system of China and discusses the requirements for satellite payloads in terms of spatial,temporal,and spectral resolution to establish a Digital Earth.The applications of land satellites under the framework of Digital Earth are introduced from the perspectives of data support,special subject services,and integrated information services.It is concluded that China’s land observation satellites and ground processing systems will be fundamental components of the Digital Earth system,in which satellite data and their derived information will serve as the principal information source and greatly promote applications of Digital Earth.

基于效能评估的卫星资源调度方法

对地观测卫星作为国家基础性战略资源,在国民经济、社会发展和国家安全等方面发挥着关键作用;一直以来,如何通过调度手段,发挥对地观测卫星资源的应用效能,使其完成更多的观测任务,是航天领域的一个研究热点;通过卫星资源效能评估的方式,对卫星对地观测效能进行事前评估的定量分析,并将效能评估结果应用在对地观测卫星资源调度上,采用一种基于KM算法的卫星资源最优调度方法,实现卫星资源在执行多个对地观测任务过程中的整体效能最大化,可为卫星资源调度、优化建设提供参考和决策支撑。

对地观测卫星姿态控制系统效能评估方法

卫星系统效能评估问题,是卫星提高工作效率和卫星方案优化设计的基础。以对地观测卫星姿态控制系统作为效能评估的对象,通过对卫星的任务需求进行分析,建立对地观测卫星姿态控制系统效能评估指标体系;基于灰色关联分析相关理论,引入熵权法计算指标权重,建立效能评估模型,计算得到综合灰色关联度,实现卫星姿态控制系统效能评估;通过数据验证所建体系具有可实现性与实用性。

海洋一号卫星观测任务规划算法设计及系统应用

针对海洋一号卫星观测任务规划需求,提出并实现了基于遗传策略的任务规划框架,解决了卫星实际使用中成像任务受卫星其他业务影响的多类型约束成像规划问题。基于海洋一号卫星实际规划业务要求,对任务规划约束和优化目标建立数学模型,提出了由预处理、窗口约束处理和组合约束处理与优化组成的三阶段规划框架。设计了多约束任务规划优化目标函数,并利用交叉、变异和种群选择等遗传机制对优化问题进行了求解。基于海洋一号卫星实际观测需求数据,对提出的算法进行了有效性和性能验证,结果表明本算法能够给出满足多类型约束的观测规划方案,并在观测时间、观测覆盖率等方面较其他策略有显著提升。研究结果表明通过优化目标函数的设计遗传算法能够实现复杂约束条件的成像规划求解,算法框架可为与海洋卫星具有相似业务特点的对地观测规划系统设计提供借鉴。

A Fast Insertion Tabu Search with Conflict-Avoidance Heuristic for the Multisatellite Multimode Crosslink Scheduling Problem

An agile earth-observing satellite equipped with multimode cameras capable of transmitting observation data to other satellites is developed to rapidly respond to requests with multiple observation modes.This gives rise to the Multisatellite Multimode Crosslink Scheduling(MMCS)problem,which involves allocating observation requests to agile satellites,selecting appropriate timing and observation modes for the requests,and transmitting the data to the ground station via the satellite communication system.Herein,a mixed integer programming model is introduced to include all complex time and operation constraints.To solve the MMCS problem,a two-stage heuristic method,called Fast insertion Tabu Search with Conflict-avoidance(FTS-C)heuristic,is developed.In the first stage,a conflict-avoidance insertion algorithm is designed to generate a high-quality initial solution by considering the requests transmission and download.Further,the tabu search-based second stage optimizes the initial solution.Finally,an extensive empirical study based on a real-world situation demonstrates that FTS-C can generate a solution with higher quality in less time than other state-of-the-art algorithms and the CPLEX solver.

基于特征参数拟合的多地面目标双星星下点轨迹规划

为解决具有多次轨道机动能力、多探测目标、多探测器协同的对地观测任务的星下点轨迹规划优化问题,提出一种基于特征参数拟合的星下点轨迹快速计算方法,并采用基于数据库的星下点轨迹拼接方法建立优化模型。首先,对描述星下点轨迹的特征参数进行分析和提炼,采用多项式对特征参数进行拟合实现快速计算;然后,根据探测目标建立观测码数据库,再进一步整理成轨迹数据库;最后,建立基于轨迹数据库的优化模型,解决整个星下点轨迹规划问题。对第11届全国空间轨道设计竞赛的固定目标快速全覆盖任务进行仿真,能够在19.19 d内完成该任务,表明所提设计方法和方案,可用于各类近圆轨道的星下点轨迹设计。