KEYNOTES

Research on Space-based Polar Integrated Information System

 Prof. Hui Wang

 Abstract

The polar issue is not a local national or regional issue. It involves the overall interests of the international community and is related to the common destiny of human survival and development. It has global significance and international influence. With the continuous expansion of China's overseas interests and the gradual improvement of its international status, China's diplomatic strategy increasingly presents a global cause and pattern, pays more and more attention to the struggle and maintenance of polar interests, and has always made contributions to the peaceful use of the polar regions and the protection of the global environment. However, China's current polar communication support capacity is relatively backward, and there is a comprehensive lack of meteorological and hydrological information; Moreover, space-based sea ice observation means are blank, which is difficult to meet the needs of China's effective Arctic shipping, polar scientific research, emergency rescue, submarine passage support and so on. In view of the incomplete status of polar infrastructure and support system in China, the concept of polar space-based integrated information support system based on "remote sensing mapping + meteorology + communication + navigation" architecture is proposed. It aims to improve China's polar infrastructure and security system and establish the necessary polar emergency rescue capacity; Unified deployment of specialized polar integrated information support system to provide support for large-scale and long-term scientific research activities in the polar region; Provide data, technology and equipment support and guarantee for polar activities such as polar regional waterway development and scientific investigation and research, and support the deepening of China's strategic layout in the polar region.

Reporter introduction

Coming soon........

Models for PolSAR Data: An Overview and New Ones

  Prof. Alejandro C Frery

 Abstract

Data obtained from Synthetic Aperture Radar exhibit a noise-like interference pattern known as speckle. Speckle makes it challenging to extract visual and automatic information from these images. Therefore, the first step in handling speckle is understanding the available models, their underlying hypotheses and limitations, and how they arose. First, we will see the building of the Wishart model. Then, we will see ways of extending it and distributions that arise. Finally, we will discuss the minimal contents, from a statistical viewpoint, an applied scientist should know to perform solid research involving SAR imagery.

Reporter introduction

Coming soon........

 Radar Signal Processing Methods for Target Feature Extractions: from uDoppler through SAR/ISAR imaging

Prof. Piotr Samczynski

Abstract

Historically radar has been developed as a sensor using electromagnetic waves to measure the distance of detected moving or stationary targets. The acronym of RADAR comes from RAdio Detection And Ranging. The acronym had been for the first time introduced in 1941. At that time, radar technology was used only in military applications. This technology has been vastly developing, and new applications for radars through the next decades have been proposed as radar imaging using synthetic aperture radar (SAR) and inverse SAR techniques. The main advantage of those technologies is the possibility to create the image of the target independently of the weather condition. The radar can operate during the day and night in most weather conditions such as rain, snow, or fog. Moreover, using lower bands of radio frequencies (RF), it is possible to penetrate through different obstacles, which gives us an additional possibility to penetrate the ground or make through the wall imaging, identifying new applications of radar technology. Additionally, the vast development of computers and rapidly increasing computational power gave the additional possibility to implement and add different signal processing techniques in radar. These techniques are, e.g., analyzes of the micro-Doppler (uDoppler) features of moving targets, allowing to easily classify different targets, such as humans, cyclists, animals, birds, and drones. These additional methods are starting nowadays to be widely used in many areas of our everyday life. Besides the implementation of these techniques in military and security systems, we can also find many implementations of these techniques in the civilian market: starting from automotive applications through applications in everyday use electronics hardware, like microwaves or washing machines, smartphones, or smartwatches, where radar technology also entered last years. The new applications also caused huge demand for developing signal processing methods to identify different and unique features of the targets using uDoppler techniques or imaging radars. This presentation overviews recently developed signal processing methods used in radar technology for target feature extraction, which is the first step of preparing the radar data for further target classification or recognition.

Reporter introduction

Prof. Piotr Samczynski received his B.Sc. and M.Sc. degrees in electronics and Ph.D. and D.Sc. degrees in telecommunications, all from the Warsaw University of Technology (WUT), Warsaw, Poland in 2004, 2005, 2010 and 2013 respectively. Since 2018, he has been the Associate Professor at the WUT; and since 2014 – a member of the WUT’s Faculty of Electronics and Information Technology Council. Prior to this, he was Assistant Profesor at WUT (2018-2010), a research assistant at the Przemyslowy Instytut Telekomunikacji S.A. (PIT S.A.) (2010-2005), and the head of PIT’s Radar Signal Processing Department (2010-2009). He is theFounder of XY-Sensing Ltd., where from 2018, he is held the CEO position.Prof. Samczynski’s research interests are in the areas of radar signal processing, passive radar, synthetic aperture radar, and digital signal processing. He is the author of over 200 scientific papers.  

Piotr Samczynski was involved in several projects for the European Research Agency (EDA), Polish National Centre for Research and Development (NCBiR), and Polish Ministry of Science and Higher Education (MiNSW), including the projects on SAR, ISAR, and passive radars. For his work, he was honored in 2020 with the Bronze Cross of Merit awarded by the President of the Republic of Poland. 

Since 2009 he has been a member of several research task groups under the NATO Science and Technology Organization (STO). He supports the research work and significantly contributed to numerous Sensors and Electronics Technology (SET) activities, particularly those related to the fields of radar signal processing, modern passive and active radars architectures, and noise radars. Since 2018 he is a Chair of the NATO SET-258 research task group (RTG) on Deployable Multiband Passive/Active Radar (DMPAR) deployment and assessment in military scenarios. In recognition of his pivotal role in enhancing the SET Programme of Work, Dr. Piotr Samczynski was presented in 2020 with the NATO STO SET Panel Early Career Award. 

Prof. Samczynski is an IEEE member since 2003 and IEEE Senior member since 2016. He is a member of IEEE AES, SP, and GRS Societies, and during 2017-2019 Prof. Samczynski was a Chair of the Polish Chapter of the IEEE Signal Processing Society. Since 2019 he is handling the position of Vice-Chairman (AES) of the IEEE Poland APS/AESS/MTTS Joint Chapter. He received IEEE Fred Nathanson Memorial Award for outstanding contribution to the field of passive radar imaging, including systems design, experimentation, and algorithm development, in 2017.

 The Next Generation of Spaceborne Synthetic Aperture Radars

Prof. Alberto Moreira

Abstract

In a changing and dynamic world, high-resolution and timely geospatial information with global coverage and access is becoming increasingly important. Spaceborne radar plays an essential role in this task, as it is the only sensor technology which provides high-resolution imagery on a global scale independent of the weather conditions and sunlight illumination.

This talk will first provide an overview on the state of the art in spaceborne synthetic aperture radar (SAR). One prominent example is the TanDEM-X mission, the first bistatic radar in space consisting of two satellites in close formation flight. TanDEM-X has already generated a global digital elevation model (DEM) of the Earth with unparalleled quality and resolution. A second edition of a global DEM, called “Change DEM” is being generated and will become available by the end of 2022. All topographic changes occurred between the two DEM acquisitions will become available for the first time on a global scale.

The second part of this talk describes the paradigm shift that is taking place in spaceborne SAR systems using multi-channel concepts with digital beamforming. The rapidly growing user community poses demanding requirements for data with higher resolution, larger coverage and higher timeliness. This is driving the development of new technologies for achieving high-resolution wide-swath (HRWS) imagery. The mission proposal Tandem-L is a prominent example of a highly innovative satellite mission for the global observation of dynamic processes on the Earth’s surface with hitherto unknown quality and resolution. Beside the scientific component, the distinguishing feature of Tandem-L is the high degree of innovation with respect to the methodology and technology. Examples are polarimetric SAR interferometry for measuring forest height, multiple-pass coherence tomography for determining the vertical structure of vegetation and ice, utilization of the latest digital beamforming techniques in combination with a large deployable reflector for increasing the swath width and imaging resolution and the close formation flying of two cooperative radar satellites with adjustable spacing.Complementary to complex SAR missions with global coverage, low-cost, lightweight systems based on NewSpace concepts are being implemented with the objective to image small areas with a very short revisit time. The combination of full-fledged SAR systems with disruptive NewSpace SAR concepts offers a wealth of new system approaches for multistatic SAR missions with enhanced imaging capabilities. One example is the HRWS mission with the MirrorSAR concept which consists of a main X-band satellite and three small receive-only satellites using the MirrorSAR concept of a space transponder. Further opportunities arise for distributed SAR system concepts using a multistatic configuration.

The ultimate goal for spaceborne SAR remote sensing is the deployment of a space-based sensor web consisting of a radar observatory with a constellation of satellites which is able to provide real-time geospatial information as an essential contribution to solving societal challenges of global dimension related to climate change, sustainable development, resource scarcity, land use, food security, environmental protection, disaster monitoring and management as well as civil security.

Reporter introduction

BIOGRAPHY – PROF. DR.‐ING. HABIL. ALBERTO MOREIRA

  Prof. Alberto Moreira is Director of the Microwaves and Radar Institute at the German Aerospace Center (DLR) and a Full Professor with the Karlsruhe Institute of Technology (KIT), Germany. His DLR’s Institute is a leading research center for SAR technologies and applications, and contributes to several scientific programs and international projects for spaceborne SAR missions. The mission TanDEM‐X, led by his Institute, has generated a global, high-resolution digital elevation model of the Earth with unprecedented accuracy. Prof. Moreira is the initiator and Principal Investigator for this mission.

Prof. Moreira is author or co‐author of more than 450 publications in international conferences and journals and is holder of more than 40 patents in the radar and antenna field. He is recipient of several international awards, including the IEEE Kiyo Tomiyasu Field Award (2007), IEEE W.R.G. Baker Award from the IEEE Board of Directors (2012), and the IEEE GRSS Distinguished Achievement Award (2014). He is an IEEE fellow and has served as President of the IEEE Geoscience and Remote Sensing Society (GRSS) in 2010.

 

Microwave Vision: Physics Driven Artificial Intelligence for SAR Image Interpretation

Prof. Feng Xu

 Abstract

In the big data era of earth observation, deep learning and other data mining technologies become critical to successful end applications. Deep learning technology has revolutionized the computer vision areas, and is gradually being applied in radar remote sensing. Over the past several years, there has been exponentially increasing interests related to deep learning techniques applied to synthetic aperture radar (SAR) imagery. However, there are issues that are specific to SAR image interpretation such as limited training samples, sensitivity to observation configuration, or weak generalization ability. There are some techniques that can be used to mitigate these issues such as fusing electromagnetic physics laws with deep neural networks, using prior constraints of physical laws to realize few-shot learning capability, etc. This talk reports the recent progresses of the author and collaborators in this area.

Reporter introduction

Coming soon........

Research on the Image-Domain Channel Mismatch Calibration Method for the Multiple azimuth channels SAR.

 Prof. Guangcai Sun

Abstract

This report introduces the research for image domain Multiple azimuth channels (MACs) synthetic aperture radar. The channel mismatch estimation is a key issue for MACs SAR. The traditional signal subspace (SSP) methods perform channel mismatch estimation in the azimuth frequency domain of the raw MACs SAR data and their estimation accuracy depends on the signal-to-noise ratio (SNR) of the raw data. In the image domain, the local maximum-likelihood weighted minimum entropy (LML-WME) algorithm is able to perform estimation by using the coarse focused SAR image with a higher SNR. But, since the closed solution of the LML-WME algorithm cannot be obtained, iterations are conducted to find the solution.

Taking advantages of the SSP and LML-WME approaches, we proposed a post-matched-filtering image-domain subspace (ISP) algorithm to estimate the channel phase error for MACs SAR. This article proposes a novel idea for estimating the channel mismatch of MACs SAR in the image domain. First, we found that the degree of freedom (DOF) of MACs signals doubles after signal reconstruction and imaging. As a result, when the channel number is not great enough, the subspace method for error estimation is unable to be implemented. To deal with this problem, we introduce a DOF compression method based on spectral filtering. This method can decrease the image-domain DOF. Finally, an image domain subspace method is proposed to estimate the channel phase error, using the focused data and selecting the high SNR region of SAR images. Compared with the conventional approaches in the signal domain, the ISP method can achieve the estimation after imaging. Since the SNR is improved after the focusing, the ISP algorithm can obtain a high level of the estimation accuracy compared with the signal domain methods. Additionally, in the estimation of the channel phase error, it is possible to select the high SNR regions in an image such that the accurate estimation can be obtainable.

Reporter introduction

Coming soon........

Ship target detection in wide ocean area based on Spaceborne SAR data

Prof. Wei Yang

 

Abstract

In the field of wide-area real-time ocean monitoring, SAR echo data are usually first processed to obtain a full-scene image, and then target detection is performed within the full-scene image. Due to the wide observation area and large amount of echo data, the traditional processing ideas need to consume a lot of computing resources and time, which has become a bottleneck restricting the wide-area ocean real-time monitoring. In order to meet the need of fast detection of spaceborne SAR wide area ocean targets, a novel detection method is proposed based on non-image domain, including the part of data generation, echo preprocessing and joint detection. In the data generation part, a decoupling method is proposed to restore the SAR image to the original echo, generating the echo data in different SCR and SNR. In the echo preprocessing part, echo is down-sampled and range compressed, which reduce data volume and improve the SCR. In the joint detection part, two hierarchical detection models, rough detection and fine detection, are used. The rough detection model uses the preprocessed data to filter out the suspected object area, and the fine detection model uses the original echo information in the range compression domain to further judge the suspected target area. This processing flow does not image the echo signal, significantly reducing the amount of data processing. Compared with the classical detection method, the efficiency is improved by tens of times, providing an idea to solve the bottleneck problem of rapid detection in wide ocean area.

An Effective Clutter Suppression Approach for the Space-borne Multi-channel in Azimuth High-resolution and Wide-swath SAR-GMTI System

Prof. Shuangxi Zhang

Abstract

An effective clutter suppression algorithm is presented for the space-borne azimuth multi-antenna high-resolution and wide-swath (HRWS) SAR system, which is based on the null-space technique. Firstly, the echo of azimuth multi-antenna HRWS SAR-GMTI system is utilized to deduce the coarse-focused image of moving targets and clutter, where the Chirp Fourier transform (CFT) in azimuth is involved. Then, the matrix form can be utilized to describe the coarse-focused image of the multi-antenna SAR system and the corresponding covariance matrix can be estimated. After that, the null-space is constructed using the covariance matrix corresponding to clutter, where at least a redundant channel freedom is required. Since the null-space vector is orthogonal to signal-space vector, it can be used to suppress the clutter. As an equivalent phase is brought by the slant-velocity, the moving targets' echo can be preserved during clutter suppression. Then, the optimization and sub-optimization vectors for clutter suppression are introduced. It is worth noting that the proposed clutter suppression algorithm is robust for the antenna mismatch, i.e., the antenna mismatch in phase and the corresponding position error. Finally, the theoretical investigations are validated using some simulation experiments, where the experiments for the azimuth multi-antenna HRWS SAR-GMTI system are included. In addition, the real measured single-platform azimuth multi-antenna HRWS SAR data experiments are also performed.

Reporter introduction

Prof. Zhang received the B.S. degree in technique of measuring control and instrument engineering from Xidian University in 2008. He received the Ph.D degree in Signal Processing at National Key Lab of Radar Signal Processing of Xidian University in 2014. He was a research fellow in National University of Singapore (NUS) during 2014-2016. Since 2016, has been a doctoral supervisor and distinguished fellow of Northwestern Polytechnical University, Shaanxi, China . He has long been engaged in the theoretical research of microwave remote sensing, the system design and signal processing of new system space-borne SAR, and space-borne radar early warning. He has presided over more than 20 projects, such as National Natural Science Foundation of China (General Program and Youth Program), and Shaanxi Provincial Innovation Capability Support Program. He has published more than 50 papers, among which he published more than 30 SCI papers. He has also applied for more than 15 patents. Among other honors, he was awarded the first prize of the “Excellent Achievement of Science and Technology Research of Shaanxi Universities”in 2022 as the leader He was selected as the "Youth Science and Technology Nova of Shaanxi Province" in 2020 and served as the editorial board of the 3rd issue of “Radar Journal”. His doctoral dissertation was awarded the excellent doctoral dissertation of China Education Society of Electronics（CESE）and the excellent doctoral dissertation of Shaanxi Province.

Satellite Observations for Global Water Cycle

 Jiancheng Shi

National Space Science Center, Chinese Academy of Sciences 

Abstract

The water cycle refers to movement and changes of water driving by solar radiation and gravity, including the water storage, phase transition and exchange between the atmosphere, oceans and land in the Earth system. Under the global trend of climate change, the water cycle is under changing that results in the significantly effects on water resource management, increased frequency and magnitude of extreme events, and food security. To understand the spatial-temporal distributions and change characteristics of water cycle at global and regional scales, a Global Water Cycle Observatory (GWCO) project will be presented. This study demonstrates the integrated global water cycle observations, not only from China’s satellites but also the other related international satellites through satellite constellations, to establish the capacity and a system for Global Water Cycle Observatory that includes the different aspects of the water cycle and links in the system mass balanced to support the water resource management under SDGs.

The scientific goal of this study is to establish the global water cycle observatory (GWCO), , to ad, vance our understanding of water cycle changes, its consequences and impacts for SDGs (UN sustainability development Goals) and stren, gthens the research efforts through international collaborations. GWCO will provide satellite observations and a new opportunity to support Earth-system and application models in verification and improvement, data assimilation, and SDGs. 

Reporter introduction

Dr. Jiancheng Shi is a senior research scientist at National Space Science Center, Chinese Academy of Sciences (CAS), Beijing, China. His research interests mainly include 1) remote sensing theory and techniques, 2) remote sensing of cryosphere components, water cycle components, and radiation energy balance, 3) development of new satellite missions, 4) synergy of remote sensing observations and Earth process models for hydrology and climatic change. He is the fellow of IEEE and SPIE, and has published more than 500 papers with nearly 16000 citations.