Latest Progress of the Chinese Meteorological Satellite Program and Core Data Processing Technologies

In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satellites(FY-2H,FY-3D,and FY-4A)and their primary objectives are introduced Second,the core image navigation techniques and accuracies of the FY meteorological satellites are elaborated,including the latest geostationary(FY-2/4)and polar-orbit(FY-3)satellites.Third,the radiometric calibration techniques and accuracies of reflective solar bands,thermal infrared bands,and passive microwave bands for FY meteorological satellites are discussed.It also illustrates the latest progress of real-time calibration with the onboard calibration system and validation with different methods,including the vicarious China radiance calibration site calibration,pseudo invariant calibration site calibration,deep convective clouds calibration,and lunar calibration.Fourth,recent progress of meteorological satellite data assimilation applications and quantitative science produce are summarized at length.The main progress is in meteorological satellite data assimilation by using microwave and hyper-spectral infrared sensors in global and regional numerical weather prediction models.Lastly,the latest progress in radiative transfer,absorption and scattering calculations for satellite remote sensing is summarized,and some important research using a new radiative transfer model are illustrated.

FY-3E:The First Operational Meteorological Satellite Mission in an Early Morning Orbit

Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.

Growing Operational Use of FY-3 Data in the ECMWF System

This paper reviews the data quality and impact of observations from the FY-3 satellite series used operationally in the ECMWF system. This includes data from the passive microwave radiometers MWHS-1, MWHS-2 and MWRI, as well as observations from the radio occultation receiver GNOS. Evaluations against background equivalents show that the quality of the observations is broadly comparable to that of similar instruments on other polar-orbiting satellites, even though biases for the passive microwave observations can be somewhat larger and more complex for some channels. An observing system experiment shows that the FY-3 instruments jointly contribute significantly to the forecast skill in the ECMWF system. Positive impact of up to 2% is seen for most variables out to the day-2 forecasts over hemispheric scales, with significant benefits for total column water vapor or for temperature and wind in the stratosphere out to day 4.

Insights into the Microwave Instruments Onboard the Fengyun 3D Satellite:Data Quality and Assimilation in the Met Office NWP System

This paper evaluates the microwave instruments onboard the latest Chinese polar-orbiting satellite, Fengyun 3D (FY- 3D). Comparing three months of observations from the Microwave Temperature Sounder 2 (MWTS-2), the Microwave Humidity Sounder 2 (MWHS-2), and the Microwave Radiation Imager (MWRI) to Met Office short-range forecasts, we characterize the instrumental biases, show how those biases have changed with respect to their predecessors onboard FY- 3C, and how they compare to the Advanced Technology Microwave Sounder (ATMS) onboard NOAA-20 and the Global Precipitation Measurement Microwave Imager (GMI). The MWTS-2 global bias is much reduced with respect to its predecessor and compares well to ATMS at equivalent channel frequencies, differing only by 0.36 ± 0.28 K (1σ) on average. A suboptimal averaging of raw digital counts is found to cause an increase in striping noise and an ascending- descending bias. MWHS-2 benefits from a new calibration method improving the 183-GHz humidity channels with respect to its predecessor and biases for these channels are within ± 1.9 K to ATMS. MWRI presents the largest improvements, with reduced global bias and standard deviation with respect to FY-3C;although, spurious, seemingly transient, brightness temperatures have been detected in the observations at 36.5 GHz (vertical polarization). The strong solar-dependent bias that affects the instrument on FY-3C has been reduced to less than 0.2 K on average for FY-3D MWRI. Experiments where radiances from these instruments were assimilated on top of a full global system demonstrated a neutral to positive impact on the forecasts, as well as on the fit to the background of independent instruments.

Impact of assimilating FY-3C MWHS2 data in the RMAPS-ST forecast system on its rainfall forecasts

In order to evaluate the impact of assimilating FY-3C satellite Microwave Humidity Sounder(MWHS2)data on rainfall forecasts in the new-generation Rapid-refresh Multi-scale Analysis and Prediction System–Short Term(RMAPS-ST)operational system,which is developed by the Institute of Urban Meteorology of the China Meteorological Administration,four experiments were carried out in this study:(i)Coldstart(no observations assimilated);(ii)CON(assimilation of conventional observations);(iii)FY3(assimilation of FY-3C MWHS2 only);and(iv)FY3+CON(simultaneous assimilation of FY-3C MWHS2 and conventional observations).A precipitation process that took place in central-eastern China during 4–6 June 2019 was selected as a case study.When the authors assimilated the FY-3C MWHS2 data in the RMAPS-ST operational system,data quality control and bias correction were performed so that the O-B(observation minus background)values of the five humidity channels of MWHS2 became closer to a normal distribution,and the data basically satisfied the unbiased assumption.The results showed that,in this case,the predictions of both precipitation location and intensity were improved in the FY3+CON experiment compared with the other three experiments.Meanwhile,the prediction of atmospheric parameters for the mesoscale field was also improved,and the RMSE of the specific humidity forecast at the 850–400 hPa height was reduced.This study implies that FY-3C MWHS2 data can be successfully assimilated in a regional numerical model and has the potential to improve the forecasting of rainfall.

极小种群濒危植物广西火桐、丹霞梧桐的叶绿体基因组特征

广西火桐(Firmiana kwangsiensis)和丹霞梧桐(F.danxiaensis)是我国南方特有物种,其分布范围狭窄,种群数量少。为了解其叶绿体基因组结构及系统发生关系,本文通过高通量测序方法获得广西火桐和丹霞梧桐的浅层基因组数据,通过生物信息学方法对叶绿体全基因组进行组装,并对其结构特征进行分析。结果表明:广西火桐和丹霞梧桐的叶绿体基因组大小分别为160,836 bp和161,253 bp,具有典型被子植物叶绿体基因组环状四分体结构,包含长度分别为89,700 bp、90,142 bp的大单拷贝区(large single copy,LSC),长度分别为19,970 bp、20,067 bp的小单拷贝区(small single copy,SSC)及长度分别为25,583 bp、25,522 bp的2个反向重复序列区(inverted repeat sequence,IR)。两个物种的叶绿体基因组共注释得到131个基因,包括86个蛋白编码基因、37个tRNA基因和8个rRNA基因。广西火桐的叶绿体基因组中共检测出26个正向重复序列、2个反向重复序列、21个回文重复序列、21个串联重复序列和98个简单重复序列;丹霞梧桐叶绿体基因组中共检测出23个正向重复序列、5个反向重复序列、21个回文重复序列、30个串联重复序列和107个简单重复序列。系统发生分析结果表明5种梧桐属(Firmiana)植物构成两个强烈支持的分支(支持率100%),一个分支为广西火桐、美丽火桐(F.pulcherrima)和火桐(F.colorata),其中广西火桐与美丽火桐构成姐妹群;另一分支是互为姐妹群的丹霞梧桐和云南梧桐(F.major)。综上所述,广西火桐和丹霞梧桐的叶绿体基因组结构、基因排列及重复序列具有较高的相似性,系统进化树将5种梧桐属物种分为两个分支,其中广西火桐和美丽火桐最近;而丹霞梧桐与云南梧桐关系最近。本研究鉴定的SSR位点可为梧桐属物种系统发生、进化关系的研究提供遗传信息。

沙漠地区1月份微波地表发射率的线性反演

基于多元函数泰勒公式和最优控制原理,首先,在塔克拉玛干沙漠部分中心区域(反演区域),利用2014年1月FY-3C微波成像仪10.65 GHz垂直极化的观测亮温、辐射传输模式(CRTM)的模拟亮温等资料,在原有地表发射率与2个影响因子的函数关系基础之上,构建了该区域1月份微波地表发射率与2、4个影响因子之间的线性反演模型。其次,以观测亮温为参考,分别将两种线性反演模型所得的地表发射率提供给CRTM模拟亮温,发现此时模拟亮温的平均偏差分别减少到原地表发射率模拟亮温平均偏差的56.36%和49.37%。最后,在整个塔克拉玛干沙漠地区(检验区域),选取用于反演日期中的1月18日、未用于反演日期中的1月29日,对两种线性反演模型进行了时间和空间上的独立性检验,结果表明,利用两种线性反演模型所得的地表发射率模拟亮温仍比原模拟亮温更接近观测,平均偏差也明显减小;两种线性反演模型对沙漠地区1月份地表发射率的反演具有一定的合理性和普适性,且4个因子的线性反演模型优于2个因子。

Hes1 Knockdown Exacerbates Ischemic Stroke Following tMCAO by Increasing ER Stress-Dependent Apoptosis via the PERK/ eIF2a/ATF4/CHOP Signaling Pathway

Apoptosis induced by endoplasmic reticulum(ER)stress plays a crucial role in mediating brain damage after ischemic stroke.Recently,Hes1(hairy and enhancer of split 1)has been implicated in the regulation of ER stress,but whether it plays a functional role after ischemic stroke and the underlying mechanism remain unclear.In this study,using a mouse model of ischemic stroke via transient middle cerebral artery occlusion(tMCAO),we found that Hes1 was induced following brain injury,and that siRNA-mediated knockdown of Hes1 increased the cerebral infarction and worsened the neurological outcome,suggesting that Hes1 knockdown exacerbates ischemic stroke.In addition,mechanistically,Hes1 knockdown promoted apoptosis and activated the PERK/eIF2a/ATF4/CHOP signaling pathway after tMCAO.These results suggest that Hes1 knockdown promotes ER stress-induced apoptosis.Furthermore,inhibition of PERK with the specific inhibitor GSK2606414 markedly attenuated the Hes1 knockdown-induced apoptosis and the increased cerebral infarction as well as the worsened neurological outcome following tMCAO,implying that the protection of Hes1 against ischemic stroke is associated with the amelioration of ER stress via modulating the PERK/eIF2a/ATF4/CHOP signaling pathway.Taken together,these results unveil the detrimental role of Hes1 knockdown after ischemic stroke and further relate it to the regulation of ER stress-induced apoptosis,thus highlighting the importance of targeting ER stress in the treatment of ischemic stroke.

Highly Selective Biomimetic Flexible Tactile Sensor for Neuroprosthetics

Biomimetic flexible tactile sensors endow prosthetics with the ability to manipulate objects,similar to human hands.However,it is still a great challenge to selectively respond to static and sliding friction forces,which is crucial tactile information relevant to the perception of weight and slippage during grasps.Here,inspired by the structure of fingerprints and the selective response of Ruffini endings to friction forces,we developed a biomimetic flexible capacitive sensor to selectively detect static and sliding friction forces.The sensor is designed as a novel plane-parallel capacitor,in which silver nanowire-3D polydimethylsiloxane(PDMS)electrodes are placed in a spiral configuration and set perpendicular to the substrate.Silver nanowires are uniformly distributed on the surfaces of 3D polydimethylsiloxane microcolumns,and silicon rubber(Ecoflex^(■))acts as the dielectric material.The capacitance of the sensor remains nearly constant under different applied normal forces but increases with the static friction force and decreases when sliding occurs.Furthermore,aiming at the slippage perception of neuroprosthetics,a custom-designed signal encoding circuit was designed to transform the capacitance signal into a bionic pulsed signal modulated by the applied sliding friction force.Test results demonstrate the great potential of the novel biomimetic flexible sensors with directional and dynamic sensitivity of haptic force for smart neuroprosthetics.

Multifunctional biomimetic tactile system via a stick-slip sensing strategy for human–machine interactions

A tactile sensor system enables natural interaction between humans and machines;this interaction is crucial for dexterous robotic hands,interactive entertainment,and other smart scenarios.However,the lack of sliding friction detection significantly limits the accuracy and scope of interactions due to the absence of sophisticated information,such as slippage,material and roughness of held objects.Here,inspired by the stick-slip phenomena in the sliding process,we have developed a multifunctional biomimetic tactile system based on the stick-slip sensing strategy,which is a universal method to detect slippage and estimate the surface properties of objects by sliding.This system consists of a flexible fingertip-inspired tactile sensor,a read-out circuit and a machinelearning module.Based on the stick-slip sensing strategy,our system was endowed with high recognition rates for slippage detection(100.0%),material classification(93.3%)and roughness discrimination(92.8%).Moreover,robotic hand manipulation,interactive games and object classification are demonstrated with this multifunctional system for comprehensive and promising human-machine interactions.

Biological receptor-inspired flexible artificial synapse based on ionic dynamics

The memristor has been regarded as a promising candidate for constructing a neuromorphic computing platform that is capable of confronting the bottleneck of the traditional von Neumann architecture.Here,inspired by the working mechanism of the G-protein-linked receptor of biological cells,a novel double-layer memristive device with reduced graphene oxide(rGO)nanosheets covered by chitosan(an ionic conductive polymer)as the channel material is constructed.The protons in chitosan and the functional groups in rGO nanosheets imitate the functions of the ligands and receptors of biological cells,respectively.Smooth changes in the response current depending on the historical applied voltages are observed,offering a promising pathway toward biorealistic synaptic emulation.The memristive behavior is mainly a result of the interaction between protons provided by chitosan and the defects and functional groups in the rGO nanosheets.The channel current is due to the hopping of protons through functional groups and is limited by the traps in the rGO nanosheets.The transition from short-term to long-term potentiation is achieved,and learning-forgetting behaviors of the memristor mimicking those of the human brain are demonstrated.Overall,the bioinspired memristor-type artificial synaptic device shows great potential in neuromorphic networks.

An artificial neuromorphic somatosensory system with spatio-temporal tactile perception and feedback functions

The advancement in flexible electronics and neuromorphic electronics has opened up opportunities to construct artificial perception systems to emulate biological functions which are of great importance for intelligent robotics and human-machine interactions.However,artificial systems that can mimic the somatosensory feedback functions have not been demonstrated yet despite the great achievement in this area.In this work,inspired by human somatosensory feedback pathways,an artificial somatosensory system with both perception and feedback functions was designed and constructed by integrating the flexible tactile sensors,synaptic transistor,artificial muscle,and the coupling circuit.Also,benefiting from the synaptic characteristics of the designed artificial synapse,the system shows spatio-temporal information-processing ability,which can further enhance the efficiency of the system.This research outcome has a potential contribution to the development of sensor technology from signal sensing to perception and cognition,which can provide a special paradigm for the next generation of bionic tactile perception systems towards e-skin,neurorobotics,and advanced bio-robots.

Bio-inspired flexible artificial synapses for pain perception and nerve injuries

Imitation of the perception system of living creatures is of great importance for the construction of artificial nerves and intelligent human-machine interfaces.However,a prominent challenge is to emulate the functions of the biological synapse,which is the basic building block of the neural system.Here,inspired by the pain perception mechanism of the living creatures,a flexible double-layer memristor was constructed,with 90%semiconducting single-wall carbon nanotubes(s-SWCNTs)covered by LiClO4 doped polyoxyethylene oxide(PEO:LiClO4)as the channel materials.The carriers(protons and Li+)from PEO:LiClO4 imitated the functions of Na+and K+in biological systems.A potentiation of the post-synaptic signal was observed with mild stimuli,while the post-synaptic signal was inhibited with severe stimuli with a pulse voltage larger than 1.4 V in this research.These behaviors resemble the sensation of pain,neuroprotection,and possible injuries to the neural system.To explore the underlying mechanism of the phenomenon,the fourier-transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),Raman spectrum,and current(IV)sweep were carried out.It was inferred that the observed results are attributable to the interaction between carriers in PEO:LiClO4 and functional groups and defects in the s-SWCNTs.The enhanced channel current results from the fulfillment of the traps by the carriers,and the suppression of the current is due to the intercalation of Li+in the s-SWCNTs.This flexible artificial synapse opens a new avenue for the construction of biocompatible electronic devices towards artificial intelligence systems.

A hybrid flexible gas sensory system with perceptual learning

Imbuing artificial sensory system with intelligence of the biological counterpart is limited by challenges in emulating perceptual learning ability at the device level.In biological systems,stimuli from the surrounding environment are detected,transmitted,and processed by receptor,afferent nerve,and brain,respectively.This process allows the living creatures to identify the potential hazards and improve their adaptability in various environments.Here,inspired by the biological olfaction system,a gas sensory system with perceptual learning is developed.As a proof-of-concept,H2S gas with various concentrations is used as the stimulation and the stimuli will be converted to pulse-like physiological signals in the designed system,which consists of a gas sensor,a flexible oscillator,and a memristor-type artificial synapse.Furthermore,the learning ability is implemented using a supervised learning method based on k-nearest neighbors(KNN)algorithm.The recognition accuracy can be enhanced by repeating training,illustrating a great potential to be used as the neuromorphic sensory system with a learning ability for the applications in robotics.

Stable epidermal electronic device with strain isolation induced by in situ Joule heating

Epidermal electronics play increasingly important roles in human-machine intetfaces.However,their efficient fabrication while maintaining device stability and reliability remains an unresolved challenge.Here,a facile in situ Joule heating method is proposed for fabricating stable epidermal electronics on a polyvinyl alcohol(PVA)substrate.Benefiting from the precise control of heating locations,the crystallization and enhanced rigidity of PVA are restricted to desired areas,leading to strain isolation of the active regions.As a result,the electronic device can be conformably attached to skin while showing negligible degradation in device performance during deformation.Based on this method,a flexible surface electromyography(sEMG)sensor with outstanding stability and highly comfortable wearability is demonstrated,showing high accuracy(91.83%)for human hand gesture recognition.These results imply that the fabrication method proposed in this research is a facile and reliable approach for the fabrication of epidermal electronics.