Comparison between Plane and Stereo Block Adjustment for ZY-3 Satellite Images

Block adjustment for satellite images cannot be solved with weak convergence geometric conditions,therefore a plane block adjustment method to improve the targeting precision of images is proposed utilizing DEM as height constraint plane block adjustment method.First,a rational function model with affine transformation is selected as the mathematical model of the satellite image plane block adjustment.Second,to update the ground coordinates of tie points(TPs),the plane coordinates of TPs are only solved in the adjustment process.Elevation values are obtained by using DEM interpolation.Finally,the plane coordinates of all TPs and orientation parameters of all satellite images are solved through plane block adjustment with a few ground control points ZY-3 nadir images for two regions are tested for plane block adjustment while ZY-3 forward-nadir-back images of the same two regions are tested for stereo block adjustment.A comparison indicates that almost the same accuracy can be obtained with plane block adjustment support using a 1∶50 000 DEM and stereo block adjustment for ZY-3 images.For ZY-3 nadir images,almost no loss of plane block adjustment accuracy occurred when global DEM with 1 km grid and SRTM with 90 m grid replaced the 1∶50 000 DEM as elevation control,.Test results demonstrate the effectiveness and feasibility of the plane block adjustment method.

A New Generation of Intelligent Mapping and Remote Sensing Scientific Test Satellite Luojia-301

With the continuous improvement of the performance and the increasing variety of optical mapping and remote sensing satellites,they have become an important support for obtaining global accurate surveying and mapping remote sensing information.At present,optical mapping and remote sensing satellites already have sub-meter spatial resolution capabilities,but there is a serious lag problem in mapping and remote sensing information services.It is urgent to develop intelligent mapping and remote sensing satellites to promote the transformation and upgrading to real-time intelligent services.Firstly,based on the three imaging systems of the optical mapping and remote sensing satellites and their realization methods and application characteristics,this paper analyzes the applicable system of the intelligent mapping and remote sensing satellites.Further,according to the application requirements of real-time,intelligence,and popularization,puts forward the design concept of integrated intelligent remote sensing satellite integrating communication,navigation,and remote sensing and focuses on the service mode and integrated function composition of intelligent remote sensing satellite.Then expounds on the performance and characteristics of the Luojia-301 satellite,a new generation of intelligent surveying and mapping remote sensing scientific test satellite.And finally summarizes and prospects the development and mission of intelligent mapping remote sensing satellites.Luojia-301 satellite integrates remote sensing and communication functions.It explores an efficient and intelligent service mode of mapping and remote sensing information from data acquisition to the application terminal and provides a real service verification platform for on-orbit processing and real-time transmission of remote sensing data based on space-ground internet,which is of great significance to the construction of China’s spatial information network.

Identification of Xunxi Shujin Decoction by TLC

[Objectives]To establish a TLC qualitative method for the determination of Radix Aconiti,Radix Aconiti Kusnezoffii,Caesalpinia sappan L.and Radix zanthoxyli.[Methods]TLC was used to study the quality of Radix Aconiti,Radix Aconiti Kusnezoffii and C.sappan L.in Xunxi Shujin Decoction,and the influencing factors were investigated to optimize the TLC conditions.[Results]In the TLC identification test of Radix Aconiti,Radix Aconiti Kusnezoffii,C.sappan L.and R.zanthoxyli in Xunxi Shujin Decoction,the spots were clear,the resolution was good,the specific value was moderate,the negative control was not disturbed,and the specificity was strong.[Conclusions]The established TLC method was simple,specific and reproducible,and could be used for the quality control of Xunxi Shujin Decoction.

China’s high-resolution optical remote sensing satellites and their mapping applications

Since the beginning of the twenty-first century,several countries have made great efforts to develop space remote sensing for building a high-resolution earth observation system.Under the great attention of the government and the guidance of the major scientific and technological project of the high-resolution earth observation system,China has made continuous breakthroughs and progress in high-resolution remote sensing imaging technology.The development of domestic high-resolution remote sensing satellites shows a vigorous trend,and consequently,a relatively stable and perfect high-resolution earth observation system has been formed.The development of high-resolution remote sensing satellites has greatly promoted and enriched modern mapping technologies and methods.In this paper,the development status,along with mapping modes and applications of China’s high-resolution remote sensing satellites are reviewed,and the development trend in high-resolution earth observation system for global and ground control-free mapping is discussed,providing a reference for the subsequent development of high-resolution remote sensing satellites in China.

Earth Observation Brain(EOB):an intelligent earth observation system

Since the twenty-first century,with the rapid development of high-resolution earth observation satellites,the earth observation satellite system has developed from the initial single satellite observation model to the current satellite constellation formed by light and small satellites observation model.All-weather and all-directional fine earth observation can now be realized.In the future,the satellite constellation,communication satellites,navigation satellites,and aircrafts are linked through dynamic linking network to form an air-space information network to realize real-time services of intelligent air-space information.To further enhance the perception,cognition,and quick response ability of the network,we propose the concept and model of the Earth Observation Brain(EOB)−the intelligent earth system based on events perception in this paper.Then,some key technologies needed to be solved in the EOB are also described.An application example is illustrated to show the process of perception and cognition in the primary stage of the EOB.In the future,EOB can observe what change of what object,the when and where to push these right information to mobile terminal of right people at the right time and right place.Global users can obtain any data,information,and knowledge in real-time through the EOB.

Remote sensing of human beings-a perspective from nighttime light

City lights,fishing boats,and oil fields are the major sources of nighttime lights,therefore the nighttime light images provide a unique source to map human beings and their activities from outer space.While most of the scholars focused on application of nighttime light remote sensing in urbanization and regional development,the actual fields are much wider.This paper summarized the applications of nighttime light remote sensing into fields such as the estimation of socioeconomic parameters,monitoring urbanization,evaluation of important events,analyzing light pollution,fishery,etc.For estimation of socioeconomic parameters,the most promising progress is that Gross Domestic Product and its growth rate have been estimated with statistical data and nighttime light data using econometric models.For monitoring urbanization,urban area and its dynamics can be extracted using different classification methods,and spatial analysis has been employed to map urban agglomeration.As sharp changes of nighttime light are associated with important socioeconomic events,the images have been used to evaluate humanitarian disasters,especially in the current Syrian and Iraqi wars.Light pollution is another hotspot of nighttime light application,as the night light is related to some diseases and abnormal behavior of animals,and the nighttime light images can provide light pollution information on large scales so that it is much easier to analyze the effects of light pollutions.In each field,we listed typical cases of the applications.At last,future studies of nighttime light remote sensing have been predicted.

Advances of geo-spatial intelligence at LIESMARS

The enhancement of computing power,the maturity of learning algorithms,and the richness of application scenarios make Artificial Intelligence(AI)solution increasingly attractive when solving Geo-spatial Information Science(GSIS)problems.These include image matching,image target detection,change detection,image retrieval,and for generating data models of various types.This paper discusses the connection and synthesis between AI and GSIS in block adjustment,image search and discovery in big databases,automatic change detection,and detection of abnormalities,demonstrating that AI can integrate GSIS.Moreover,the concept of Earth Observation Brain and Smart Geo-spatial Service(SGSS)is introduced in the end,and it is expected to promote the development of GSIS into broadening applications.

Internet intelligent remote sensing scientific experimental satellite LuoJia3-01

With the development of new technologies such as 5G/6G,cloud computing,the Internet of Things,and artificial intelligence,humanity has entered the era of the interconnection of everything.The traditional remote sensing satellite data acquisition,processing,and application models have been unable to meet the popular and real-time application needs.In order to meet the service needs of the geospatial information industry in the era of the Internet of Things,it has become an inevitable trend to move from isolated remote sensing satellites to space-based information networks.

VNLSTM-PoseNet: A novel deep ConvNet for real-time 6-DOF camera relocalization in urban streets

Image-based relocalization is a renewed interest in outdoor environments,because it is an important problem with many applications.PoseNet introduces Convolutional Neural Network(CNN)for the first time to realize the real-time camera pose solution based on a single image.In order to solve the problem of precision and robustness of PoseNet and its improved algorithms in complex environment,this paper proposes and implements a new visual relocation method based on deep convolutional neural networks(VNLSTM-PoseNet).Firstly,this method directly resizes the input image without cropping to increase the receptive field of the training image.Then,the image and the corresponding pose labels are put into the improved Long Short-Term Memory based(LSTM-based)PoseNet network for training and the network is optimized by the Nadam optimizer.Finally,the trained network is used for image localization to obtain the camera pose.Experimental results on outdoor public datasets show our VNLSTM-PoseNet can lead to drastic improvements in relocalization performance compared to existing state-of-theart CNN-based methods.

Large-scale automatic block adjustment from satellite to indoor photogrammetry

Block Adjustment(BA)is a critical procedure in the geometric processing of satellite images,responsible for compensating and correcting the geometric positioning errors of the images.The accuracy of the photogrammetric products,including Digital Orthophoto Map(DOM),Digital Elevation Model(DEM),Digital Line Graphic(DLG),and Digital Raster Graphic(DRG),directly depends on the accuracy of BA results.In recent years,the rapid development of related technologies such as Artificial Intelligence(AI),Computer Vision(CV),Unmanned Aerial Vehicles(UAVs)and big data has greatly facilitated and transformed the classical BA in photogrammetry.This paper first reviews the current status of BA and then looks into the future.First,this paper provides a brief review of the key technologies involved in BA,including image matching,the establishment of adjustment model,the determination of the parameters and the detection of gross error.Then,taking the intercross and fusion of current technologies such as AI,cloud computing and big data with photogrammetry into account,this paper explores the future trends of photogrammetry.Finally,four typical cases of large-scale adjustment are introduced,including large-scale BA without Ground Control Points(GCPs)for optical stereo satellite images,large-scale BA with laser altimetry data for optical stereo satellite images,large-scale BA for UAV oblique photogrammetry,and large-scale BA for indoor photogrammetry in caves with a large number of close-range images.

过渡金属(TM=V,Cr,Mn,Fe,Co,Ni)掺杂GeSe的高温铁磁半导体薄膜

具有高温铁磁性的IV族金属硫族化物磁性半导体薄膜是半导体自旋电子器件所需要的重要材料.本文采用固体源化学气相沉积法制备了一系列过渡金属元素(TM=V,Cr,Mn,Fe,Co和Ni)掺杂GeSe的多晶半导体薄膜样品.磁性测量表明,Mn,Fe和Co掺杂的GeSe薄膜表现出较强的铁磁性,居里温度(TC)分别高达277,255和243 K,而V,Cr和Ni掺杂GeSe的多晶薄膜表现出较弱的铁磁性.磁电输运测量表明,Mn,Fe和Co掺杂GeSe的多晶薄膜具有相对较高的空穴浓度,在300 K下高达~1020cm^(-3).基于实验和计算结果的进一步分析表明,Mn,Fe和Co掺杂GeSe的多晶薄膜中的强铁磁性归因于载流子增强的Ruderman-KittelKasuya-Yosida相互作用.我们的研究结果展示了过渡金属掺杂GeSe的磁性半导体薄膜的丰富多样性,并为相关基础研究和器件应用提供了一个新平台.

From digital Earth to smart Earth

This article will analyze the achievements of the digital Earth concept and further introduce two key technologies,the internet of things and cloud computing.Both these technologies are accelerating the development of digital Earth toward a new concept—smart Earth.The objective of this article is to discuss the architecture,infrastructure,and typical applications for smart Earth and to elaborate on trends of the movement from digital Earth to smart Earth.

Spatio-temporal-spectral observation model for urban remote sensing

Taking cities as objects being observed,urban remote sensing is an important branch of remote sensing.Given the complexity of the urban scenes,urban remote sensing observation requires data with a high temporal resolution,high spatial resolution,and high spectral resolution.To the best of our knowledge,however,no satellite owns all the above character-istics.Thus,it is necessary to coordinate data from existing remote sensing satellites to meet the needs of urban observation.In this study,we abstracted the urban remote sensing observation process and proposed an urban spatio-temporal-spectral observation model,filling the gap of no existing urban remote sensing framework.In this study,we present four applications to elaborate on the specific applications of the proposed model:1)a spatiotemporal fusion model for synthesizing ideal data,2)a spatio-spectral observation model for urban vegetation biomass estimation,3)a temporal-spectral observation model for urban flood mapping,and 4)a spatio-temporal-spectral model for impervious surface extraction.We believe that the proposed model,although in a conceptual stage,can largely benefit urban observation by providing a new data fusion paradigm.

A framework design for the Chinese National Disaster Reduction System of Systems(CNDRSS)

China is one of the most disaster-prone countries in the world.Currently,the disaster prevention and relief mechanism in China is mainly based on single disaster types and is implemented by different ministries and divisions in single administrative regions.Subsequently,the available resources,including data,services,materials,and human resources,cannot be shared and used effectively.Based on the idea of an observation system of systems and a business system of systems,this paper presents an integrated framework for a Chinese National Disaster Reduction System of Systems(CNDRSS)to address this issue.The CNDRSS framework aims to achieve data sharing and collaboration among different disaster-related ministries/institutions by providing one-stop services for all phases of disaster management and linking together existing and planned disaster-related business systems and observation systems.The key technologies use federated databases and a web service to integrate multiple disaster management systems among different ministries/institutions and a sensor web to integrate airborne,space-borne,and in-situ observations through the web service.These event-driven focused-services connecting the various observations,processing,and mapping processes can meet the requirements for complex disasterchain systems.

Spatio-temporal-spectral-angular observation model that integrates observations from UAV and mobile mapping vehicle for better urban mapping

In a complex urban scene,observation from a single sensor unavoidably leads to voids in observations,failing to describe urban objects in a comprehensive manner.In this paper,we propose a spatio-temporal-spectral-angular observation model to integrate observations from UAV and mobile mapping vehicle platform,realizing a joint,coordinated observation operation from both air and ground.We develop a multi-source remote sensing data acquisition system to effectively acquire multi-angle data of complex urban scenes.Multi-source data fusion solves the missing data problem caused by occlusion and achieves accurate,rapid,and complete collection of holographic spatial and temporal information in complex urban scenes.We carried out an experiment on Baisha Town,Chongqing,China and obtained multi-sensor,multi-angle data from UAV and mobile mapping vehicle.We first extracted the point cloud from UAV and then integrated the UAV and mobile mapping vehicle point cloud.The inte-grated results combined both the characteristics of UAV and mobile mapping vehicle point cloud,confirming the practicability of the proposed joint data acquisition platform and the effectiveness of spatio-temporal-spectral-angular observation model.Compared with the observation from UAV or mobile mapping vehicle alone,the integrated system provides an effective data acquisition solution toward comprehensive urban monitoring.

Signal acquisition of Luojia-1A low earth orbit navigation augmentation system with software defined receiver

Low Earth Orbit(LEO)satellite navigation signal can be used as an opportunity signal in the case of a Global Navigation Satellite System(GNSS)outage,or as an enhancement by means of traditional GNSS positioning algorithms.No matter which service mode is used,signal acquisition is a prerequisite for providing enhanced LEO navigation services.Compared with the medium orbit satellite,the transit time of the LEO satellite is shorter.Thus,it is of great significance to expand the successful acquisition time range of the LEO signal.Previous studies on LEO signal acquisition are based on simulation data.However,signal acquisition research based on real data is crucial.In this work,the signal characteristics of LEO satellites:power space density in free space and the Doppler shift of LEO satellites are individually studied.The unified symbolic definitions of several integration algorithms based on the parallel search signal acquisition algorithm are given.To verify these algorithms for LEO signal acquisition,a Software Defined Receiver(SDR)is developed.The performance of these integration algorithms on expanding the successful acquisition time range is verified by the real data collected from the Luojia-1A satellite.The experimental results show that the integration strategy can expand the successful acquisition time range,and it will not expand indefinitely with the integration duration.The performance of the coherent integration and differential integration algorithms is better than the other two integration algorithms,so the two algorithms are recommended for LEO signal acquisition and a 20 ms integration duration is preferred.The detection threshold of 2.5 is not suitable for all integration algorithms and various integration durations,especially for the Maximum-to-Mean Ratio indicator.

Geoinformatics education in China

The paper gives an overview of the current status of education in geoinformatics in China.First,the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the scientific and technological development.It then presents how the development affects the education and training in China.In the paper,universities and institutes in China that can award academic degrees related to geoinformatics are summarized,and undergraduate majors are briefly introduced.Next,the paper reports the work having been done by the national expert group on Surveying and Mapping,including the revision of discipline catalog and guide for graduate education and requirements.A list of typical curricula in geoinformatics education is suggested.Activities on promoting the graduate student exchange platform are presented.Finally,a case study of geoinformatics education in Wuhan University is discussed.

Deep learning for change detection in remote sensing:a review

A large number of publications have incorporated deep learning in the process of remote sensing change detection.In these Deep Learning Change Detection(DLCD)publications,deep learning methods have demonstrated their superiority over conventional change detection methods.However,the theoretical underpinnings of why deep learning improves the performance of change detection remain unresolved.As of today,few in-depth reviews have investigated the mechanisms of DLCD.Without such a review,five critical questions remain unclear.Does DLCD provide improved information representation for change detection?If so,how?How to select an appropriate DLCD method and why?How much does each type of change benefits from DLCD in terms of its performance?What are the major limitations of existing DLCD methods and what are the prospects for DLCD?To address these five questions,we reviewed according to the following strategies.We grouped the DLCD information assemblages into the four unique dimensions of remote sensing:spectral,spatial,temporal,and multi-sensor.For the extraction of information in each dimension,the difference between DLCD and conventional change detection methods was compared.We proposed a taxonomy of existing DLCD methods by dividing them into two distinctive pools:separate and coupled models.Their advantages,limitations,applicability,and performance were thoroughly investigated and explicitly presented.We examined the variations in performance between DLCD and conventional change detection.We depicted two limitations of DLCD,i.e.training sample and hardware and software dilemmas.Based on these analyses,we identified directions for future developments.As a result of our review,we found that DLCD’s advantages over conventional change detection can be attributed to three factors:improved information representation;improved change detection methods;and performance enhancements.DLCD has to surpass the limitations with regard to training samples and computing infrastructure.We envision this review can boost developments of deep learning in change detection applications.

Challenges and opportunities for the development of MEGACITIES

Urbanization is one of the most important social and economic phenomena in the world today.This paper reviews the formation of megacities and summarizes the main problems,challenges and opportunities faced by the sustainable development of such large megacities.Issues discussed include the problems of land subsidence in megacities,environmental issues,traffic problems and energy supply aspects.The sustainable development of megacities in other parts of the world provided the references and experiences for the countermeasures of megacity planning and development in China.The vision of Digital Earth and Digital Cities can play a major role in the efficient management and sustainable growth of such megacities all around the world.

BOOK REVIEW

Remote sensing image fusion:a practical guide,by Christine Pohl and John van Genderen,Boca Raton,London,New York,CRC Press,Taylor and Francis Group,September,2016,266 pp.,£89.00(hardback),ISBN 9781498730020 Written by two of the best-known researchers in the field of remote sensing fusion,this book gives a good introduction to the subject of remote sensing image fusion.This textbook is relevant to newcomers and specialists alike because it provides in-depth explanations,as well as new insights on recent advances in the field.Readers will find this to be a very practical guide to enter this exciting technology.The book has seven chapters,which I’ll briefly introduce in the following paragraphs,before discussing the key features of this book.