电离层及热层空间天气研究微小卫星

Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,*,I-SWEAT Micro-Satellite Mission:,Ionospheric Space Weather Effects in Auroral Thermosphere,Andrew Yau, D.D. Wallis,University of Calgary,Yunlong Lin, J. McConnell, M. Shepherd, B. Solheim,York University,P. Harrison,1, R.B. Langley,2,，,W. Lunscher,3, J.M. Noel,4,1,Magellan Bristol,2,UNB,3,COM DEV,4,RMC,Supported by,Canadian Space Agency,电离层及热层空间天气研究微小卫星：,I-SWEAT,1,Outline,报告内容,Focus of talk: Science,报告焦点,: 科学,Scientific Motivation,科学动机,Scientific Objective,科学目标,Mission Concept,科学任务的概念研究,Results from Mission Concept Study,初步结果和结论,我的国语不太行, 用英语作这个报告, 希望各位多多原谅, ,2,Scientific Motivation,科学动机,(1),Understand,physics of ionosphere-thermosphere response,to,space weather: magnetic storms and substorms,研究空间天气(磁暴,和亚暴,),对电离层以及热层的影响,Advance,prediction capability of space weather effects,改进有关空间天气影响电离层以及热层的预测,预报,监测和预警,Ionosphere,: Total Electron Content (TEC) increase at mid/high latitude,电离层：在中，高纬区域“电子浓度总含量”的增长,Scintillation: disrupt radio communications and GPS navigation,对无线电信号闪烁的影响： 扰乱无线电通讯和,GPS,导航,Thermosphere,: Heating, density increase, expansion at high latitude,热层： 加热过程，密度增长，在高纬的扩张,Anomalous orbit drag to low-Earth-orbit (LEO) satellites,对低地球轨道卫星轨道保持的影响：产生不规则轨道拖曳,3,Space Weather Effects in Ionosphere,磁暴期间电子浓度总含量,(TEC) 增加,及 GPS 信号闪烁,TEC increase and GPS signal scintillation in magnetic storm,Storm electron density (SED) increase,over North America in Oct. 2003 “super-storm” Foster 2005,2003,年,10,月北美地区磁暴期间电子密度增长,GPS scintillation,at Ithaca, NY, in minor magnetic storm Kintner 2007,2001,年,9,月小磁暴期间同样也有,GPS,信号闪烁,4,Scientific Motivation,科学动机,(,2,),Understand,physics of ionosphere-thermosphere response,to,space weather: magnetic storms and substorms,研究空间天气(磁暴,和亚暴,),对电离层以及热层的影响,Advance,prediction capability of space weather effects,改进有关空间天气影响电离层以及热层的预测,预报,监测和预警,Ionosphere,: Total Electron Content (TEC) increase at mid/high latitude,电离层：在中，高纬区域“电子浓度总含量”的增长,Scintillation: disrupt radio communications and GPS navigation,对无线电信号闪烁的影响： 扰乱无线电通讯和,GPS,导航,Thermosphere,: Heating, density increase, expansion at high latitude,热层： 加热过程，密度增长，在高纬的扩张,Anomalous orbit drag to low-Earth-orbit (LEO) satellites,对低地球轨道卫星轨道保持的影响：产生不正常轨道拖曳下降,5,Space Weather Effects in Thermosphere,磁暴期间高层大气扩张,导致低地球轨道卫星不正常轨道下降,Atmospheric expansion & anomalous orbit drag in magnetic storm,Anomalous drag of CHAMP orbit by,500 m,(,SMA),in Oct. 2003 storm at,410 km altitude,2003,年,10,月的磁暴对,410,公里高度的,CHAMP,卫星产生,500,米的轨道下降,2,increase in atmospheric mass density,at 410 km,inferred on CHAMP Sutton 2005,2003,年超过,2,倍的大气密度增长对,410,公里高度的,CHAMP,卫星的影响,6,Space Weather & Anomalous Orbit Drag,空间天气对人造卫星轨道的影响,Spacecraft collision avoidance:,Effective avoidance strategy requires orbit prediction to within ,3-5 km,“State-of-the-art” orbit prediction:,Ap and F,10.7,based (e.g. STK),Has large uncertainty: up to,20 km,Orbit Error Simulation/Analysis:,Storm/substorm related anomalous orbit drag contributes significantly to errors in orbit prediction.,避免卫星在轨碰撞；,提高轨道预报能力；,轨道预报偏差的模拟和分析；,磁暴和亚暴对低地球轨道卫星的轨道预报的正确性具有重要影响,February 11, 2009,U.S. And Russian Satellites Collide,“Two communications satellites one Russian, one American cracked up in silent destruction The American satellite was an Iridium, ”,纽约时报（,2009,年,2,月,11,日）对美苏卫星相撞的报道：美国卫星是提供,卫星电话,服务的铱星,7,Scientific Objective,科学目标,Scientific Objective,科学目标,Measurements,探测需求,Instruments,测仪器,Investigation Objectives,研究目标,8,Mission Concept,卫星计划和概念,Micro-satellite:,3 instruments on “QuickSat” Bus,Orbit:,Polar LEO: 300-700 km,Sun- or non-Sun-sync,Science operations:,Operation in selected orbits / orbit segments,卫星,: “快捷”,微小卫星,仪器: 中性粒子质量及速度分析器, 双频GPS接收,机, 磁,强计,轨道: 高倾角轨道,，或者极轨；高度,: 300-700 公里,9,System Architecture,卫星,系统和空间任构成,Instrument Payload:,ANA: Atmospheric Neutral Analyzer,DGR: Dual-frequency GPS Receiver,FMG: Fluxgate Magnetometer,中性粒子质量及速度分析器,双频GPS接收,机,磁,强计,Ground System:,Amateur-radio type ground station,Mission Operations Center,Multi Science Operation Center (SOC),多元化分布式地面站,Uplink/downlink:,VHF/UHF,VHF/UHF,通讯,10,I-SWEAT QuickSat Spacecraft,加拿大,“快捷”微小卫星平台,FMG deployed,on boom,磁,强计,DGR side-facing antenna,双频GPS接收,机,VHF Uplink Antenna,X (ram),Z (nadir),ANA ram-facing entrance slit,中性粒分析,仪,Solar panels deployment,11,Atmospheric Neutral Analyzer (ANA),中性粒子质量及速度分析,仪探测原理,1. Entrance aperture,accepts neutrals; deflects ions,2. Electron beam,ionizes a fraction,of neutral;,retains incident velocity,3.,Accelerate ions,to same perpendicular energy/charge,6. CCD,images ion positions,(,hence,neutral velocities),5.,Accept only,resonant ions,4. RF Analyzer,energizes ions,of “resonant” velocity,(,M,/,q,),12,Dual-Frequency GPS Receiver (DGR),双频,GPS,接收机设计,Heritage,Simplified version of e-POP GAP,GAP co-developed by UNB and Magellan Bristol,GAP has array of 5 GPS receivers networked to 4 patch antennas and 1 occultation antenna,Design,2 GPS receivers networked to 2 antennas,Re-use GAP interface, power, GPS cards,Modified GAP implementation,CASSIOPE/e-POP GAP electronics,CASSIOPE/e-POP GAP electronics,13,Fluxgate Magnetometer (FMG),磁通门磁强计的设计,Measurement Goal: field-aligned currents 1,A/m,2,along 1 km path,Sampling: 32 samples/sec ,500 m/sample; resolution: 1 nT,Fluxgate magnetometer: measures magnetic field vector components by modulating permeability of ferro-magnetic rings inside detection coils,Non-zero magnetic flux inside coils induces voltage at 2 modulation freq.,Low-freq. feedback current through coil, ambient magnetic flux component,Design:,Based on CASSIOPE/e-POP Magnetic,Field Instrument (MGF),Resolution: 1/16 nT; Range: 65,536 nT,CASSIOPE/e-POP MGF sensor assembly,14,I-SWEAT Summary,初步研究结果和结论,Mission Concept:,QuickSat bus in low-Earth polar orbit,Instruments: Atmospheric Neutral Analyzer, Dual-frequency GPS Receivers, Fluxgate Magnetometer,Low-cost science operations; multiple ground stations,Scientific Objective:,Study space weather effects in ionosphere-thermosphere,TEC enhancement; Thermosphere expansion; anomalous orbit drag,经过二年的初步论证和概念设计，我们提出利用加拿大的,“快捷”,微小卫星平台在高倾角低地球轨道（轨道,高度: 300-700 公里,）上对电离层及热层的中性粒子，磁场和电子密度总含量进行探测，确切掌握空间天气在磁暴和亚暴期间的变化对电离层和热层的影响，进而深入了解其对卫星的影响。 这些影响至少包括：电子密度总含量增长，,GPS,信号闪烁，热层扩张和异常轨道下降。进一步改进空间天气影响电离层及热成层的预测和预报方法将直接有利于卫星轨道设计和轨道操作。,这颗电离层及热层空间天气研究微小卫星（,I-SWEAT,）将至少携带,3,种探测仪器（中性粒子质量速度分析仪, 双频,GPS 接收,机, 磁,强计），利用多元化分布式地面站独立完成低成本、高效率的长期科学探测任务。与其他空间天气研究卫星同步进行集群式组网探测，将进一步深化我们对空间天气物理过程的理解，扩大,I-SWEAT,对空间天气研究的意义。,卡尔加里大学和约克大学将汇同其他加拿大大学和研究部门进行科学载荷和卫星平台的研制，我们欢迎各种形式的合作研究和联合探测。,15,