2023年7月11日至2023年7月20日,第28届国际大地测量学和地球物理学联合会(The International Union of Geodesy and Geophysics,IUGG)大会在德国柏林举行。按照IUGG传统,国际大地测量协会中国委员会(CNC-IAG)组织国内十余家单位编写了...2023年7月11日至2023年7月20日,第28届国际大地测量学和地球物理学联合会(The International Union of Geodesy and Geophysics,IUGG)大会在德国柏林举行。按照IUGG传统,国际大地测量协会中国委员会(CNC-IAG)组织国内十余家单位编写了“中国大地测量国家报告(2019—2023)”,分别总结了2019至2023年4年期间的中国大地测量各分支学科研究进展。本文主要归纳和总结了中国大地测量学科近几年的整体进展,侧重各领域代表性研究进展,主要内容包括基准框架、综合PNT与弹性PNT、重力场与垂直基准、GNSS精密产品、多源传感器组合导航和海洋大地测量6个研究方向。此外,结合国际大地测量及相关交叉学科的发展趋势,对我国大地测量学科未来发展提出了几点建议。展开更多
Qinghai-Tibet Plateau is the most complex region for crustal thickness inversion, while high-resolu- tion earth gravity model （EGM） makes it possible to obtain high precision gravity anomaly, which is a key pa- rame...Qinghai-Tibet Plateau is the most complex region for crustal thickness inversion, while high-resolu- tion earth gravity model （EGM） makes it possible to obtain high precision gravity anomaly, which is a key pa- rameter to depict the Earth＇ s inner structure in geodesy domain. On the basis of this principle, we calculated the Bouguer gravity anomalies in Qinghai-Tibet Plateau with EGM2008 and SRTM6.0 by efficient high-degree spherical harmonic synthesis algorithm. In order to obtain the gravity anomaly caused by Moho density mutant, the noises caused by the topography was removed by wavelet details. Then, the crustal thickness was corrected on the basis of CRUST 2.0 with the deep-large-scale single density interface formula. The inversion result indi- cates that the crustal thickness in Qinghai-Tibet Plateau is between 50 km and 75 kin, which is in correspon- dence with the recent science research result. Compared with the 2 degree CRUST 2.0 model, the spatial resolution of crustal thickness in our research can reach 40 arc minutes. In addition, there is a positive relationship between the inversed crustal thickness and topography, which can prove the effectiveness of Airy-Heiskanen isostatic model in gravity reduction.展开更多
Taking China as the region for test, the potential of the new satellite gravity technique, satelliteto-satellite tracking for improving the accuracy of regional gravity field model is studied. With WDM94 as referenee,...Taking China as the region for test, the potential of the new satellite gravity technique, satelliteto-satellite tracking for improving the accuracy of regional gravity field model is studied. With WDM94 as referenee, the gravity anomaly residuals of three models, the latest two GRACE global gravity field model （EIGEN_GRACE02S, GGM02S） and EGM96, are computed and compared. The causes for the differences among the residuals of the three models are discussed. The comparison between the residuals shows that in the selected region, EIGEN_GRACE02S or GGM02S is better than EGM96 in lower degree part （less than 110 degree）. Additionally, through the analysis of the model gravity anomaly residuals, it is found that some systematic errors with periodical properties exist in the higher degree part of EIGEN and GGM models, the results can also be taken as references in the validation of the SST gravity data.展开更多
A new temporal gravity field model called WHU-Grace01s solely recovered from Gravity Recovery and Climate Experiment （GRACE） K-Band Range Rate （KBRR） data based on dynamic integral approach is presented in this pa...A new temporal gravity field model called WHU-Grace01s solely recovered from Gravity Recovery and Climate Experiment （GRACE） K-Band Range Rate （KBRR） data based on dynamic integral approach is presented in this paper. After meticulously preprocessing of the GRACE KBRR data, the root mean square of its post residuals is about 0.2 micrometers per second, and seventy-two monthly temporal solutions truncated to degree and order 60 are computed for the period from January 2003 to December 2008. After applying the combi- nation filter in WHU-Grace01s, the global temporal signals show obvious periodical change rules in the large-scale fiver basins. In terms of the degree variance, our solution is smaller at high degrees, and shows a good consistency at the rest of degrees with the Release 05 models from Center for Space Research （CSR）, GeoForschungsZentrum Potsdam （GFZ） and Jet Pro- pulsion Laboratory 0PL）. Compared with other published models in terms of equivalent water height distribution, our solution is consistent with those published by CSR, GFZ, JPL, Delft institute of Earth Observation and Space system （DEOS）, Tongji University （Tongji）, Institute of Theoretical Geodesy （ITG）, Astronomical Institute in University of Bern （AIUB） and Groupe de Recherche de Geodesie Spatiale （GRGS}, which indicates that the accuracy of WHU-Grace01s has a good consistency with the previously published GRACE solutions.展开更多
Dynamic characteristics of large structures,such as tall buildings,long_span suspension,cable_stayed bridges and tall chimneys,are key to assess their drift and stress conditions.The dynamic characteristics of large s...Dynamic characteristics of large structures,such as tall buildings,long_span suspension,cable_stayed bridges and tall chimneys,are key to assess their drift and stress conditions.The dynamic characteristics of large structures are difficult to measure directly under the condition of earthquakes or strong winds using traditional techniques such as laser collimator,total station and accelerometers.Therefore there is a great need for developing new method or technique for this purpose.Recent advances in Global Positioning System (GPS) technology provide a great opportunity to monitor long_period changes of structures reliably.GPS receivers capable to gauge the motion at the centimeter or sub_centimeter level with sampling frequency 10Hz or even 20 Hz are now available from several manufacturers.To the authors’ knowledge,the capability of identifying dynamic characteristics from GPS observations has not been widely verified.For the feasibility study on using kinematic GPS technology to identify the dynamic characteristics of tall buildings,some experiments were conducted in a simulative environment.This paper discusses in detail the experiment device,and the ways through them GPS data are recorded,processed and analyzed.With post_processing version of NovAtel’s Softsurv software and auto_regressive (AR) spectral analysis method,relative displacements and corresponding vibrating frequencies have been derived from GPS observations.The results indicate that the dynamic characteristics can be identified accurately by kinematic GPS technology.展开更多
Four wetland maps for all China have been produced,based on Landsat and CBERS-02B remote sensing data between 1978 and 2008 (1978,1990,2000 and 2008).These maps were mainly developed by manual interpretation and valid...Four wetland maps for all China have been produced,based on Landsat and CBERS-02B remote sensing data between 1978 and 2008 (1978,1990,2000 and 2008).These maps were mainly developed by manual interpretation and validated by substantial field investigation in 2009.Based on these maps,we analyzed the 2008 wetland distribution in China and discussed wetland changes and their drivers over the past 30 years.(i) There were about 324097 km 2 of wetlands in 2008,for which inland marshes or swamps were the most common wetland type (35%),with lakes (26%) second.Most of the wetlands were in Heilongjiang,Inner Mongolia,Qinghai and Tibet,occupying about 55% of the national wetland area.(ii) From 1978 to 2008,China's wetland area continually and significantly decreased,by about 33% based on changes in the wetland map.This was in sharp contrast to the increase in artificial wetlands,which increased by about 122%.Inland marshes accounted for the main loss of total wetlands from 1978 to 2000.From 2000 through 2008,riverine and lacustrine wetlands constituted the main wetland loss.Fortunately however,the rate of wetland loss decreased from 5523 to 831 km 2 /a.(iii) The change ratio of lost natural wetlands (including inland and coastal wetlands) to non-wetlands has decreased slightly over the past 30 years.From 1978 to 1990,nearly all natural wetlands (98%) lost were transformed into non-wetlands.However,the ratio declined to 86% from 1990 to 2000,and to 77% from 2000 to 2008.(iv) All Chinese provinces were divided into three groups according to patterns of wetland changes,which could relate to the driving forces of such changes.Tibet was completely different from other provinces,as it was one representative example in which there was a net wetland increase,because of global warming and decreased human activity since 1990.Increased economic development caused considerable wetland loss in most eastern provinces,and artificial wetlands increased.展开更多
It is important to quantify mass variations in the Antarctic ice sheet hybrid filtering scheme employing a combination of the decorrelated to study the global sea-level rise and climate change. A filter P3M6 and 300 k...It is important to quantify mass variations in the Antarctic ice sheet hybrid filtering scheme employing a combination of the decorrelated to study the global sea-level rise and climate change. A filter P3M6 and 300 km Fan filter was used, and the sur- face mass variations over the Antarctic are recovered from GRACE CSR RL04 monthly gravity field models from August 2002 to June 2010. After deduction of leakage errors using the GLDAS hydrological model and postglacial rebound effects using the glacial isostatic adjustment model IJ05, the variations in the ice sheet mass are obtained. The results reveal that the rate of melting of the Antarctic ice sheet is 80.0 Gt/a and increasing and contributes 0.22 mm/a to the global sea-level rise; the mass loss rate is 78.3 Gt/a in the West Antarctic and 1.6 Gt/a in the East Antarctic. The average mass loss rate increases from 39.3 Gt/a for the period 2002-2005 to 104.2 Gt/a for the period 2006-2010, and its corresponding contribution to the global sea-level rise increases from 0.11 to 0.29 mm/a, which indicates accelerated ice mass loss over the Antarctic since 2006. Moreover, the mass accumulation rates for Enderby Land and Wilkes Land along the coast of East Antarctica decrease for the period 2006-2008 but increase evidently after 2009.展开更多
The problems of the earth's gravity fields' visualization are both focus and puzzle currently. Aiming at multiresolution rendering, modeling of the Earth's gravity fields' data is discussed in the pape...The problems of the earth's gravity fields' visualization are both focus and puzzle currently. Aiming at multiresolution rendering, modeling of the Earth's gravity fields' data is discussed in the paper by using LOD algorithm based on Quad Tree. First, this paper employed the method of LOD based on Quad Tree to divide up the regional gravity anomaly data, introduced the combined node evaluation system that was composed of viewpoint related and roughness related systems, and then eliminated the T-cracks that appeared among the gravity anomaly data grids with different resolutions. The test results demonstrated that the gravity anomaly data grids' rendering effects were living, and the computational power was low. Therefore, the proposed algorithm was a suitable method for modeling the gravity anomaly data and has potential applications in visualization of the earth's gravity fields.展开更多
文摘2023年7月11日至2023年7月20日,第28届国际大地测量学和地球物理学联合会(The International Union of Geodesy and Geophysics,IUGG)大会在德国柏林举行。按照IUGG传统,国际大地测量协会中国委员会(CNC-IAG)组织国内十余家单位编写了“中国大地测量国家报告(2019—2023)”,分别总结了2019至2023年4年期间的中国大地测量各分支学科研究进展。本文主要归纳和总结了中国大地测量学科近几年的整体进展,侧重各领域代表性研究进展,主要内容包括基准框架、综合PNT与弹性PNT、重力场与垂直基准、GNSS精密产品、多源传感器组合导航和海洋大地测量6个研究方向。此外,结合国际大地测量及相关交叉学科的发展趋势,对我国大地测量学科未来发展提出了几点建议。
基金supported by the National 973 Program of China(2013CB733302)the National Natural Science Foundation of China(41131067,41174020,41374023)+2 种基金the open fund of State Key Laboratory of Geographic Information Engineering(SKLGIE2013-M-1-3)the open fund of Key Laboratory of Geospace Environment and Geodesy,Ministry of Education(13-02-05)the Fundamental Research Funds for the Central Universities(2014214020203)
文摘Qinghai-Tibet Plateau is the most complex region for crustal thickness inversion, while high-resolu- tion earth gravity model （EGM） makes it possible to obtain high precision gravity anomaly, which is a key pa- rameter to depict the Earth＇ s inner structure in geodesy domain. On the basis of this principle, we calculated the Bouguer gravity anomalies in Qinghai-Tibet Plateau with EGM2008 and SRTM6.0 by efficient high-degree spherical harmonic synthesis algorithm. In order to obtain the gravity anomaly caused by Moho density mutant, the noises caused by the topography was removed by wavelet details. Then, the crustal thickness was corrected on the basis of CRUST 2.0 with the deep-large-scale single density interface formula. The inversion result indi- cates that the crustal thickness in Qinghai-Tibet Plateau is between 50 km and 75 kin, which is in correspon- dence with the recent science research result. Compared with the 2 degree CRUST 2.0 model, the spatial resolution of crustal thickness in our research can reach 40 arc minutes. In addition, there is a positive relationship between the inversed crustal thickness and topography, which can prove the effectiveness of Airy-Heiskanen isostatic model in gravity reduction.
基金Project supported by the National Natural Science Foundation of China (No.40374006 No.40574005 +1 种基金 No.40304001 No.40234039) .
文摘Taking China as the region for test, the potential of the new satellite gravity technique, satelliteto-satellite tracking for improving the accuracy of regional gravity field model is studied. With WDM94 as referenee, the gravity anomaly residuals of three models, the latest two GRACE global gravity field model （EIGEN_GRACE02S, GGM02S） and EGM96, are computed and compared. The causes for the differences among the residuals of the three models are discussed. The comparison between the residuals shows that in the selected region, EIGEN_GRACE02S or GGM02S is better than EGM96 in lower degree part （less than 110 degree）. Additionally, through the analysis of the model gravity anomaly residuals, it is found that some systematic errors with periodical properties exist in the higher degree part of EIGEN and GGM models, the results can also be taken as references in the validation of the SST gravity data.
基金supported by the National 973Program of China(2013CB733302)the National Natural Science Foundation of China(41131067,41174020,41374023,41474019)+2 种基金the Open Research Fund Program of the State Key Laboratory of Geodesy and Earth's Dynamics(SKLGED2015-1-3-E)the open fund of State Key Laboratory of Geographic Information Engineering(SKLGIE2013-M-1-3)the open fund of Key Laboratory of Geospace Environment and Geodesy,Ministry of Education(13-02-05)
文摘A new temporal gravity field model called WHU-Grace01s solely recovered from Gravity Recovery and Climate Experiment （GRACE） K-Band Range Rate （KBRR） data based on dynamic integral approach is presented in this paper. After meticulously preprocessing of the GRACE KBRR data, the root mean square of its post residuals is about 0.2 micrometers per second, and seventy-two monthly temporal solutions truncated to degree and order 60 are computed for the period from January 2003 to December 2008. After applying the combi- nation filter in WHU-Grace01s, the global temporal signals show obvious periodical change rules in the large-scale fiver basins. In terms of the degree variance, our solution is smaller at high degrees, and shows a good consistency at the rest of degrees with the Release 05 models from Center for Space Research （CSR）, GeoForschungsZentrum Potsdam （GFZ） and Jet Pro- pulsion Laboratory 0PL）. Compared with other published models in terms of equivalent water height distribution, our solution is consistent with those published by CSR, GFZ, JPL, Delft institute of Earth Observation and Space system （DEOS）, Tongji University （Tongji）, Institute of Theoretical Geodesy （ITG）, Astronomical Institute in University of Bern （AIUB） and Groupe de Recherche de Geodesie Spatiale （GRGS}, which indicates that the accuracy of WHU-Grace01s has a good consistency with the previously published GRACE solutions.
文摘Dynamic characteristics of large structures,such as tall buildings,long_span suspension,cable_stayed bridges and tall chimneys,are key to assess their drift and stress conditions.The dynamic characteristics of large structures are difficult to measure directly under the condition of earthquakes or strong winds using traditional techniques such as laser collimator,total station and accelerometers.Therefore there is a great need for developing new method or technique for this purpose.Recent advances in Global Positioning System (GPS) technology provide a great opportunity to monitor long_period changes of structures reliably.GPS receivers capable to gauge the motion at the centimeter or sub_centimeter level with sampling frequency 10Hz or even 20 Hz are now available from several manufacturers.To the authors’ knowledge,the capability of identifying dynamic characteristics from GPS observations has not been widely verified.For the feasibility study on using kinematic GPS technology to identify the dynamic characteristics of tall buildings,some experiments were conducted in a simulative environment.This paper discusses in detail the experiment device,and the ways through them GPS data are recorded,processed and analyzed.With post_processing version of NovAtel’s Softsurv software and auto_regressive (AR) spectral analysis method,relative displacements and corresponding vibrating frequencies have been derived from GPS observations.The results indicate that the dynamic characteristics can be identified accurately by kinematic GPS technology.
基金supported by the National High-tech R&D Program of China(2009AA122003)
文摘Four wetland maps for all China have been produced,based on Landsat and CBERS-02B remote sensing data between 1978 and 2008 (1978,1990,2000 and 2008).These maps were mainly developed by manual interpretation and validated by substantial field investigation in 2009.Based on these maps,we analyzed the 2008 wetland distribution in China and discussed wetland changes and their drivers over the past 30 years.(i) There were about 324097 km 2 of wetlands in 2008,for which inland marshes or swamps were the most common wetland type (35%),with lakes (26%) second.Most of the wetlands were in Heilongjiang,Inner Mongolia,Qinghai and Tibet,occupying about 55% of the national wetland area.(ii) From 1978 to 2008,China's wetland area continually and significantly decreased,by about 33% based on changes in the wetland map.This was in sharp contrast to the increase in artificial wetlands,which increased by about 122%.Inland marshes accounted for the main loss of total wetlands from 1978 to 2000.From 2000 through 2008,riverine and lacustrine wetlands constituted the main wetland loss.Fortunately however,the rate of wetland loss decreased from 5523 to 831 km 2 /a.(iii) The change ratio of lost natural wetlands (including inland and coastal wetlands) to non-wetlands has decreased slightly over the past 30 years.From 1978 to 1990,nearly all natural wetlands (98%) lost were transformed into non-wetlands.However,the ratio declined to 86% from 1990 to 2000,and to 77% from 2000 to 2008.(iv) All Chinese provinces were divided into three groups according to patterns of wetland changes,which could relate to the driving forces of such changes.Tibet was completely different from other provinces,as it was one representative example in which there was a net wetland increase,because of global warming and decreased human activity since 1990.Increased economic development caused considerable wetland loss in most eastern provinces,and artificial wetlands increased.
基金supported by the National Basic Research Program of China (Grant No. 2007CB714405)the National Natural Science Foundation of China (Grant No. 40874002)the Program for New Century Excellent Talents in University (Grant No. NCET-07-0635)
文摘It is important to quantify mass variations in the Antarctic ice sheet hybrid filtering scheme employing a combination of the decorrelated to study the global sea-level rise and climate change. A filter P3M6 and 300 km Fan filter was used, and the sur- face mass variations over the Antarctic are recovered from GRACE CSR RL04 monthly gravity field models from August 2002 to June 2010. After deduction of leakage errors using the GLDAS hydrological model and postglacial rebound effects using the glacial isostatic adjustment model IJ05, the variations in the ice sheet mass are obtained. The results reveal that the rate of melting of the Antarctic ice sheet is 80.0 Gt/a and increasing and contributes 0.22 mm/a to the global sea-level rise; the mass loss rate is 78.3 Gt/a in the West Antarctic and 1.6 Gt/a in the East Antarctic. The average mass loss rate increases from 39.3 Gt/a for the period 2002-2005 to 104.2 Gt/a for the period 2006-2010, and its corresponding contribution to the global sea-level rise increases from 0.11 to 0.29 mm/a, which indicates accelerated ice mass loss over the Antarctic since 2006. Moreover, the mass accumulation rates for Enderby Land and Wilkes Land along the coast of East Antarctica decrease for the period 2006-2008 but increase evidently after 2009.
文摘The problems of the earth's gravity fields' visualization are both focus and puzzle currently. Aiming at multiresolution rendering, modeling of the Earth's gravity fields' data is discussed in the paper by using LOD algorithm based on Quad Tree. First, this paper employed the method of LOD based on Quad Tree to divide up the regional gravity anomaly data, introduced the combined node evaluation system that was composed of viewpoint related and roughness related systems, and then eliminated the T-cracks that appeared among the gravity anomaly data grids with different resolutions. The test results demonstrated that the gravity anomaly data grids' rendering effects were living, and the computational power was low. Therefore, the proposed algorithm was a suitable method for modeling the gravity anomaly data and has potential applications in visualization of the earth's gravity fields.
