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1.
Improving the accuracy of GRACE Earth's gravitational field using the combination of different inclinations 总被引:5,自引:0,他引:5
In this paper,the GRACE Earth's gravitational field complete up to degree and order 120 is recovered based on the combination of different inclinations using the energy conservation principle.The results show that because different inclinations of satellite are sensitive to the geopotential coefficients with different degrees/and orders m.the design of GRACE exploiting 89° inclination can effectively improve the accuracy of geopotential zonal harmonic coefficients.However,it is less sensitive to the geopotential tesseral harmonic coefficients.Accordingly.the second group of GRACE exploiting lower inclination is required to determine high-accurately the geopotential tesseral harmonic coefficients and cover the shortage of the single group of GRACE exploiting 89° inclination.Two groups of GRACE individually exploiting 89° (82°-84°)inclinations are the optimal combination of the Earth'S gravitational field recovery complete up to degree and order 120.In the degree 120,the joint accuracy of cumulative geoid height based on two groups of GRACE individually exploiting 89° and 83° inclinations is averagely two times higher than the accuracy of a group of GRACE exploiting 89° inclination. 相似文献
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冰后回弹对南极地区冰盖质量变化影响的研究 总被引:3,自引:3,他引:0
全球海平面变化关系着人类的生存和发展,一直以来就是科学界重点关注的问题;而南极地区存储的冰是影响海平面变化最主要的因素。主要详细地阐述了冰后回弹的基本理论,以及利用GRACE重力数据计算冰后回弹的基本理论;并推导了相关的计算公式。最后,利用GRACE月重力场数据对冰后回弹和南极地区质量变化进行了试算。实验结果表明:南极地区冰后回弹效应范围为-0.987~20.3 mm/a;其中在极点附近的冰后回弹效应较强。 相似文献
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现有重力卫星任务存在时空分辨率不足、时空混频以及重力场信号各向异性等局限性.分别对重力卫星串联编队的轨道高度、轨道倾角、星间距离等指标进行仿真分析,就重力卫星串联编队星座模式对重力场时空分辨率的影响进行了数值分析.结果表明,卫星轨道高度的选择需要兼顾重力场信号衰减和卫星寿命等因素,以维持在300~400 km为优;轨道倾角选择应充分考虑极空白问题的影响,极空白区大小不宜超过6°;星间距离大于250 km时,重力场精度的提升并不明显,重力卫星串联编队星间距离设为50~100 km为优.重力卫星串联编队星座模式可同时有效提升地球重力场时空分辨率,实现时变重力场的各向同性探测. 相似文献
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In this paper, the GRACE Earth's gravitational field complete up to degree and order 120 is recovered based on the combination of different inclinations using the energy conservation principle. The results show that because different inclinations of satellite are sensitive to the geopotential coefficients with different degrees l and orders m, the design of GRACE exploiting 89° inclination can effectively improve the accuracy of geopotential zonal harmonic coefficients. However, it is less sensitive to the geopotential tesseral harmonic coef- ficients. Accordingly, the second group of GRACE exploiting lower inclination is required to determine high-accurately the geopotential tesseral harmonic coefficients and cover the shortage of the single group of GRACE exploiting 89° inclination. Two groups of GRACE individually exploiting 89° + (82°-84°) inclinations are the optimal combination of the Earth's gravitational field recovery complete up to degree and order 120. In the degree 120, the joint accuracy of cumulative geoid height based on two groups of GRACE individually exoloiting 89° and 83° inclinations is averagely two times higher than the accuracy of a group of GRACE exploiting 89~ inclination. 相似文献
7.
Simulation of the Earth''s gravitational field recovery from GRACE using the energy balance approach 总被引:1,自引:0,他引:1
ZHENG Wei LU Xiaolei HSU Houtse SHAO Chenggang LUO Jun WANG Nengchao 《自然科学进展(英文版)》2005,15(7):596-601
Based on the measurement principles of GRACE satellites, the observation equations are set up using the energy balance approach. The Earth's gravitational field complete up to degree and order 120 is recovered applying the preconditioning conjugate gradient iterative approach by numerical simulation. Assuming an accuracy of 1 μms in range-rate measurements of the K-band microwave ranging system, the matching relationships of accuracies of K-band microwave ranging system, SuperSTAR Accelerometer, position vector and velocity vector measurements are investigated. 相似文献
8.
Trend of China land water storage redistribution at medi- and large-spatial scales in recent five years by satellite gravity observations 总被引:4,自引:0,他引:4
The GRACE (Gravity Recovery and Climate Experiment) satellite gravity mission has provided a new method to study land water
mass redistribution at medi- and long-spatial scales in recent years. We estimate continental water mass redistribution in
China using GRACE observations during 2003 to 2007. The results show some large regions with increase or decrease of land
water mass storage in the central northern region, Tibetan Plateau, the Three Gorges region, the place where Qinghai, Sichuan
and Gansu provinces meet, and the Altun Mountains region in the Xinjiang Uygur Autonomous Region. In the first two regions,
it is obvious that water (ice) mass storages are decreasing. Water mass in the central northern region decreases at a linear
rate of 2.4 cm/a equivalent water height, equal to 5.2 billion cubic meters per year during the five years’ period, and water
mass depletion in Hebei Province is ∼ 4.5 billion cubic meters per year in the same period, which is consistent with the average
water mass depletion of 4.0 billion cubic meters per year of overused underground water in the recent 30 years estimated by
Hebei Province Water Resources Bureau. Furthermore, GRACE can detect the water mass accumulation of ∼ 5 cm equivalent water
height within the region spreading over about 0.12 million square kilometers due to the Three Gorges dam construction in June
2003. We also find a water mass gain of ∼ 1.1 cm/a in the areas where Qinghai, Sichuan and Gansu provinces meet. This indicates
that the climate of these regions has been becoming gradually humid in recent years.
Supported by Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-202), National Natural Science
Foundation of China (Grant No. 40674038), and Program of Key Laboratory of Space Environment and Geodesy of Ministry of Education
of China 相似文献
9.
The long-term continuous gravity observations obtained by the superconducting gravimeters (SG) at seven globally-distributed stations are comprehensively analyzed. After removing the signals related to the Earth’s tides and variations in the Earth’s rotation, the gravity residuals are used to describe the seasonal fluctuations in gravity field. Meanwhile, the gravity changes due to the air pressure loading are theoretically modeled from the measurements of the local air pressure, and those due to land water... 相似文献
10.
针对GRACE(gravity recovery and climate experiment)时变重力场模型中因高阶项误差引起的南北条带误差,分析利用滤波算法消除该条带误差的基本原理,着重研究Fan滤波和高斯滤波的理论差异,最后利用CSR(center for space research of texas university in austin)提供的Level-2 RL05版本时GRACE重力场数据对2010年全球陆地水储量月变化进行了数值计算,并分别利用Fan滤波和高斯滤波对相关误差进行了处理,并将计算结果与GLDAS(global land data assimilation system)水文模型的结果进行了验证分析。比较结果表明:Fan滤波相对于高斯滤波,能够有效地消除模型高阶项误差引起的条带误差。 相似文献