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单颗星下点高度计卫星可进行一维海面高度测量，但时空分辨率较低，对涡旋的探测能力不足。梳状高度计卫星编队可提升海面高度时空分辨率，增强对涡旋的识别探测能力。为定量分析高度计编队下的涡旋探测能力，本文在黑潮延伸体海域开展观测仿真实验，对海平面高度进行沿轨采样，经优化插值算法处理后得到逐天海面高度异常数据场并进行涡旋识别与统计分析。此外，本文还同步开展了单颗星下点高度计和成像高度计卫星涡旋探测仿真实验及对比分析。结果表明，梳状高度计卫星编队在涡旋数量、极性、半径及振幅等方面识别效果较好，与成像高度计探测结果相近。 相似文献
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为弥补测高数据在近海区域因为编辑准则被剔除而导致近海测量数据质量不高的缺点,利用5参数模型的两种形式和Ice-2模型对Jason-2卫星在中国南海部分海域的海洋回波波形进行了波形重跟踪的研究,并选择20个海洋回波波形,依据最小二乘原理进行计算、分析、对比,发现5参数模型的指数形式的结果和Ice-2模型结果非常接近。研究结果表明,在开阔的海域,对Jason-2波形进行3种方法波形重跟踪时,可以优先考虑Ice-2模型。波形重跟踪技术能够提高卫星测高数据利用率,为科学研究提供可靠的数据保障。 相似文献
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HY-2A卫星雷达高度计海面高度测量分析与评估 总被引：1，自引：0，他引：1
HY-2A卫星是我国首颗自主海洋动力环境卫星，已连续运行6年多。卫星上搭载的主载荷雷达高度计能够实现全天候、全天时全球海面高度、有效波高和海面风速的观测，这些观测数据已经广泛用于海洋防灾减灾、资源开发和海上安全等领域。为了全面了解HY-2A卫星雷达高度计多年来的整体观测性能，本文选取了2012年10月26日至2017年8月27日间的全部观测数据IGDR产品进行综合评价。通过自交叉和与Jason-2互交叉两种手段对HY-2A卫星雷达高度计测高能力进行评估。计算HY-2A升降轨自交叉点的测高不符值，发现HY-2A卫星雷达高度计在近全球海域内、升降轨高度异常差小于30cm的限制条件下，平均绝对高度误差为5.81cm，高度异常标准差为7.76cm；限制观测区域为南北纬60°范围内、海面高度异常升降轨交叉点处的差小于10cm的情况下，平均绝对误差可达3.95cm，海面高度异常标准差达4.76cm。通过和Jason-2卫星的互交叉，发现在南北纬66°范围内，交叉点高度异常差小于30cm的情况下，HY-2A和Jason-2的海面高度异常平均绝对误差为5.86cm，标准差为7.52cm，如果在该海域内将海面高度异常差限制在10cm内，平均绝对误差和标准差分别达到4.19cm和4.98cm。HY-2A卫星雷达高度计已经达到国际同类卫星雷达高度计测高水平，可以满足海洋科学研究、海洋环流反演等的需求。 相似文献
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神舟四号高度计波形数据预处理和信息提取 总被引：1，自引：0，他引：1
神舟四号(SZ-4)高度计在国内首次提供了星载雷达高度计回波波形数据.本文中作者分析了SZ-4高度计回波波形的特点,完成波形数据的预处理,并在此基础上完成初步的信息提取.在数据预处理方面,通过SZ-4高度计水陆边界处波形的特点,提出了波形最大幅度控制的方法,筛选回波波形.在波形归一化处理过程中,发现SZ-4高度计波形中存在双峰现象,并指出第二个峰为异常波形区.在波形信息提取方面,利用波形重新跟踪得到的半功率点计算出SZ-4高度计高度跟踪补偿误差,并根据高度计天线指向角和回波波形下降沿斜率之间的关系,从波形后沿提取天线指向角信息.分析结果表明,SZ-4高度计天线指向比较平稳,而跟踪补偿由于变化较大,在计算海面高度时,应作为一项误差源被考虑到. 相似文献
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中国近海海面高度异常资料再处理 总被引：1，自引：0，他引：1
卫星海面高度异常产品再处理的研究多集中在欧洲和美国近海,中国近海尚未有过。在产生AVISO(Archiving Validation and Interpolation of Satellite Oceanographic Data)全球0.25°多颗卫星海面高度异常产品时,只用了1/3~1/2的部分沿轨资料,给区域海洋动力学研究造成了一定的限制。本研究尝试利用多颗卫星的所有沿轨资料及25个测潮站的观测资料,通过最优插值方法产生一份新的中国近海海面高度异常资料。新资料的空间分辨率仍为0.25°,但使用了来自3颗卫星(Jason-1、Jason-2、Cryo Sat-2)的所有沿轨资料及25个测潮站的观测资料。新资料的范围为10°S~50°N、90°~160°E。新资料与AVISO资料的对比分析表明新资料更接近沿轨海面高度异常观测,同时也更接近测潮站资料。与AVISO资料相比,新资料与沿轨海面高度异常观测的均方根误差降低了10.03%,与测潮站资料的均方根误差降低了9.6%。 相似文献
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HY-2A卫星雷达高度计数据的全球统计评价及质量分析 总被引：6，自引：4，他引：2
自HY-2A卫星发射以来,针对HY-2A卫星雷达高度计产品的交叉定标、真实性检验及质量评估工作一直在持续开展。本文主要以HY-2A卫星高度计第44周期的IGDR产品数据为例,通过使用全球分布图、二维直方图和每日均值统计的方法完成了与Jason-2IGDR产品的比对验证,同时对主要环境校正参数及地球物理产品的数据质量稳定性进行了分析,结果显示高度计产品数据质量较稳定,此外利用HY-2A卫星升降轨交叉点海面高度差、与Jason-2卫星交叉点海面高度差以及沿轨海平面异常数据分析的方法进行了HY-2A卫星高度计观测系统的性能评估,结果显示,HY-2A卫星海面高度精度约为7.48cm,精度接近Jason-2,能满足海洋应用与科学研究的需要。 相似文献
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论文首先从理论上简要阐述了星载海洋高度计海面回波的散射机理和回波信号后向散射模型;其后,利用Matlab数学工具,通过对我国＂神州四号＂飞船下传的大量高度计观测数据进行IQ采样数据提取、数据处理以及统计分析,进行了星载海洋高度计海面回波信号的统计特性分析与研究. 相似文献
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三维成像雷达高度计(China Imaging Altimeter,CIALT)是中科院空间中心在传统高度计的基础上,结合偏离天底点观测技术与高度跟踪测量技术、合成孔径技术和干涉技术发展起来的新型雷达高度计.其中,偏离天底点技术是为了增大刈幅宽度,高度跟踪技术是为了兼容海陆信息的观测,合成孔径技术是为了增加方位向分辨率,干涉技术是为了测量像素点的高程值.CIALT相当于是一部Ku波段、小于5°入射角的SAR,它的成像机理与SAR和InSAR基本相似,同时也能够达到传统高度计那样的厘米量级的精确度.但是,CIALT的入射角小于5°,它发射的电磁波不满足发生Bragg散射和二尺度散射的条件,只能发生准镜面散射.因此,CIALT不能完全应用SAR的一些遥感机理和研究算法,但是可以在SAR的研究基础上发展自己的遥感机理和研究算法.CIALT技术主要是解决增加有效测量点和减小时间间隔的问题,它满足了现代海洋研究与应用对于海洋参数采样空间间隔和时间间隔的要求.它在海洋三维立体成像、海洋大地水准面、洋流、中尺度涡、海面风场、海浪和潮汐等方面有良好的应用前景. 相似文献
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验潮站资料为评定卫星测高海面高度观测值的精度提供了有效途径。基于数据编辑准则筛选出HY-2A数据，通过引入NCEP实时大气压模型，解决了HY-2A卫星任务后期测高数据产品中部分干对流层延迟项和大气逆压校正项不可用的问题。在此基础上，将HY-2A海面高观测值与验潮站数据进行时空匹配，在选取的9个站点上进行了相关系数和标准差计算。结果表明，两者相关系数平均约为0.676 9，最优可达0.898 7，平均标准差为0.089 5 m。整体验证结果表明，HY-2A卫星测高数据质量符合设计指标，达到预期水平，为海洋重力场反演等应用研究提供了新的可靠数据源。 相似文献
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AbstractThe ocean mass variability inferred from Gravity Recovery and Climate Experiment (GRACE) satellites mission is challenged by the stripes and the leakage across land-ocean boundary. The recently released GRACE mascons solutions are advanced by applying constraints that remove efficiently the stripes and dual leakage correction that restores the coastal ocean mass variability. Here we quantitatively evaluate the improvement in the Arctic Ocean mass variability by GRACE mascons. To do so, we compare the combination of GRACE solutions (including the mascons solutions and traditional spherical harmonic coefficients (SHCs) solutions) and the steric estimates against the altimeter observations. Our results suggest that mascons solutions produce stronger correlations compared to SHCs solutions, especially along the coastal zone, indicating the importance of the dual leakage correction. Stronger correlation is produced by the mascons over a small basin in the interior of the Arctic Ocean, suggesting that mascons solutions deliver better ocean mass variability than the SHCs solutions. Since the comparisons are carried out over two sub-basins, we conclude that mascons are able to provide better regional ocean mass variability that may have implications for regional sea level budget, in particular over the coastal zone. 相似文献
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针对海洋测高卫星未来发展趋势,提出了Ku/Ka/C三频高度计进行组合测距的设想。给出了高度计相位中心至海面距离的随机误差模型,分析表明电离层延迟改正是影响海面高测量分辨率和精度的重要因素。其次利用典型电离层参数计算表明电离层2阶以上项对高度计测距的影响在毫米级以下,可忽略其影响。通过计算分析,在1Hz采样且不滤波条件下,Ka/C组合改正电离层1阶项精度可优于3mm,基本消除电离层的影响,测距总精度达到3.5cm。通过Ku/C/Ka三频组合测距误差分析,三频电离层改正残余误差比双频改正更大,因此如果采用三频组合测距体制,则建议在数据处理中采取Ku/C、Ka/C组合形式改正电离层,这种体制可充分利用各频段特点,进一步提高宽阔海域、冰区、近海区域的海面测量精度和有效数据比例。 相似文献
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The ocean signal for this study is the sea surface height due to the slowly varying (greater than 5-day) ocean processes, which are predominantly the deep ocean mesoscale. These processes are the focus of present assimilation systems for monitoring and predicting ocean circulation due to ocean fronts and eddies and the associated environmental changes that impact real time activities in areas with depths greater than about 200 m. By this definition, signal-to-noise may be estimated directly from altimeter data sets through a crossover point analysis. The RMS variability in crossover differences is due to instrument noise, errors in environmental corrections to the satellite observation, and short time period oceanic variations. The signal-to-noise ratio indicates that shallow areas are typically not well observed due to the high frequency fluctuations. Many deep ocean areas also contain significant high frequency variability such as the subpolar latitudes, which have large atmospheric pressure systems moving through, and these in turn generate large errors in the inverse barometer correction. Understanding the spatial variations of signal to noise is a necessary prerequisite for correct assimilation of the data into operational systems. 相似文献
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The ocean signal for this study is the sea surface height due to the slowly varying (greater than 5-day) ocean processes, which are predominantly the deep ocean mesoscale. These processes are the focus of present assimilation systems for monitoring and predicting ocean circulation due to ocean fronts and eddies and the associated environmental changes that impact real time activities in areas with depths greater than about 200 m. By this definition, signal-to-noise may be estimated directly from altimeter data sets through a crossover point analysis. The RMS variability in crossover differences is due to instrument noise, errors in environmental corrections to the satellite observation, and short time period oceanic variations. The signal-to-noise ratio indicates that shallow areas are typically not well observed due to the high frequency fluctuations. Many deep ocean areas also contain significant high frequency variability such as the subpolar latitudes, which have large atmospheric pressure systems moving through, and these in turn generate large errors in the inverse barometer correction. Understanding the spatial variations of signal to noise is a necessary prerequisite for correct assimilation of the data into operational systems. 相似文献
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The primary experiment on the Geodynamics Experimental Ocean Satellite‐3 (GEOS‐3) is the radar altimeter. This experiment's major objective is to demonstrate the utility of measuring the geometry of the ocean surface, i.e., the geoid. Results obtained from this experiment so far indicate that the planned objectives of measuring the topography of the ocean surface with an absolute accuracy of ±5 m can be met and perhaps exceeded. The GEOS‐3 satellite altimeter measurements have an instrument precision in the range of ±25 cm to ±50 cm when the altimeter is operating in the “short pulse”; mode. After one year's operations of the altimeter, data from over 5,000 altimeter passes have been collected. With the mathematical models developed and the altimeter data presently available, mapping of local areas of ocean topography has been realized to the planned accuracy levels and better. This paper presents the basic data processing methods employed and some interesting results achieved with the early data. Plots of mean sea surface heights as inferred by the altimeter measurements are compared with a detailed 1o × 1° gravimetric geoid. 相似文献
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Abstract The SEASAT Geophysical Data Record (GDR) file includes a number of corrections for instruments, atmospheric effects, coastal effects, and geophysical effects. However, the transient sea surface variation due to the ocean circulation and wind surge is not implemented. In this research an interactive numerical scheme, based on the vertically integrated hydrodynamic equations, is developed to make this correction. Since the exactness of the transient sea surface depends upon the exactness of the input meteorological data, a method is also developed for extracting surface wind speed and direction from weather charts for the interactive hydrodynamic numerical algorithm. The application of the algorithm over the Hudson Bay of Canada demonstrates that this technique can easily be applied to any regional altimeter data over a water‐covered area. The resulting transient sea surface profiles and the comparisons between wind fields derived from the weather charts and altimeter inferred wind fields over Hudson Bay for revolution numbers 559, 564, and 574 are presented. 相似文献
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Study on wave energy resource assessing method based on altimeter data——A case study in Northwest Pacific 总被引：1，自引：0，他引：1
波浪能是一种重要的海洋可再生能源,在开发波浪能之前需要对波浪能的时空分布状况进行可靠的评估。高度计可以提供比海浪模式更为准确的海浪现场观测结果,可以作为波浪能资源评估的一种新的手段。高度计数据的优势在于对海浪有效波高的观测具有较高的精度。为了发挥高度计数据的特点和优势,实现高度计数据在波浪能资源评估研究中的应用,本文建立了一种适合于高度计数据的局部海域波浪能资源的评估方法,主要包括数据的选择和处理;评价指标体系的建立;区域等级划分标准的建立。然后,以西北太平洋为例论述了该方法的具体应用。研究表明:本文建立的评估方法可以有效的评估研究海域波浪能资源的储量和时空分布状况,可为波能电站的建站选址和波能转换装置的设计和运行提供科学的参考依据。 相似文献
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The Seasat altimeter is designed to measure three parameters important to oceanography: height of the spacecraft above the ocean surface (h ), significant wave height (H_{1/3} ), and ocean backscatter coefficient (sigmadeg ) from which surface winds may be inferred. Since the measurement process is indirect, and the measurement environment is complicated by many factors affecting the instrument readings, corrections to the raw data are needed before they are used to compute geophysical parameters. These corrections are accomplished by the Seasat altimeter sensor file algorithms. The purpose of this paper is to describe these algorithms, why they are needed, how they are implemented, and their evaluation using in-flight data. 相似文献