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31.
对比研究了Shepard方法和连续曲率张力样条法及Kriging法在高程观测值稀疏和空缺区域中的插值效果,然后基于精化的ICESat数据集,利用连续曲率张力样条法建立了两极冰盖的格网时间序列模型,给出了极地冰盖高程的变化速率分布,并与卫星交叉点差值方法得到的相应值进行了对比分析。 相似文献
32.
针对青藏高原山地冰川区早期DEM数据缺乏、精度低、覆盖范围小等问题,以普若岗日冰川和雅弄冰川为例,利用解密的早期高分辨率间谍卫星KH-9立体像对,建立了基于KH-9数据的山地冰川DEM提取技术流程,并以ICESat GLAS高程数据为基准对提取的DEM进行了精度评价和精度影响分析。结果表明：无论是在普若岗日冰川区还是雅弄冰川区,所获取的DEM精度均完全满足估算山地冰川长时间尺度物质平衡的精度要求。KH-9数据具有空间分辨率高,地面覆盖范围广,成像时间较早（1971-1980年）等特点,可为山地冰川物质平衡研究提供很好的基础数据源。 相似文献
33.
概述了GLAS高度计的在轨性能，分析了其数据产品的精度。利用高精度的ICESat卫星测高数据，以及第21次中国南极科学考察内陆冰盖考察GPS的实测资料，验证了此次考察中南极内陆冰盖Dome A最高点可能区域选取的正确性，并分析了Dome A最高点位置测定的准确性。 相似文献
34.
High-accuracy topographical information extraction based on fusion of ASTER stereo-data and ICESat/GLAS data in Antarctica 总被引：1，自引：0，他引：1
In order to better support Antarctic inland ice sheet expedition from Zhongshan Station to Dome A, the topographic data are
necessary. At present, although the entire Antarctic DEM provided by RAMP (Radarsat Antarctic Mapping Project) was estimated
at the highest horizontal (spatial) resolution of about 200 m, the real horizontal resolution of the DEM varies from place
to place depending on the density and scale of the original source data. For ice shelves and the inland ice sheet, the horizontal
resolution is about 5 km; the vertical accuracy is estimated to be ±50 m in interior East Antarctic ice sheet and away from
the mountain ranges. Therefore, more accurate topographic data are unavailable in Antarctica. In order to meet the requirements
of high-accuracy topographic information for further researches, this paper mainly addresses a fusion study of ASTER stereo
pairs and ICESat/GLAS altimetry data for extraction of high-accuracy DEM in East Antarctica, based on the high horizontal
resolution (15 m) of ASTER and vertical accuracy (13.8 cm) of ICESat/GLAS. First, some altimetry data were selected as vertical
control points to reduce errors of image correlation matching during the extraction of ASTER-based DEM. Second, ice sheet
altimetry data derived from ICESat were used to generate DEM ranging from 75° to 81°S because existing ASTER data do not cover
this area and high density of the coverage of ICESat altimetry data. Finally, the DEM in coverage of the expedition route
was produced. The analysis of result reveals that the DEM accuracy is improved significantly. The absolute vertical accuracy
of DEM is higher than 15 m in some cases and higher than 30 m for all the areas along the expedition route except from the
009-001 scene; the interior accuracy is higher than 15 m and higher than 7 m in some cases. It can meet the requirements of
topographic map at 1:50000 scale, which is an economic and advantageous method to produce the topographic products.
Supported by National Natural Science Foundation (Grant No. 40606002), Surveying and Mapping in Chinese Antarctic Expedition
Area (Grant No. 1469990711109-1), National Key Technology R & D Program (Grant No. 2006BAD18B01), and GLA12 dataset of ICESat/GLAS
in National Snow and Ice Data Center (NSIDC) 相似文献
35.
Arcsecond-level accuracy of NASA's ICESat (Ice, Cloud, and land Elevation Satellite) satellite laser altimeter beam pointing
angle is required to satisfy the scientific goal of detecting centimeter-level elevation changes, over time, in the Greenland
and Antarctic ice sheets. Two different approaches, termed “topographic inferred” and “direct detection”, were examined for
calibrating the laser pointing angle (that is, detecting and removing pointing determination bias) at the 1.5-arcsec level,
using information independent of the onboard pointing instrumentation. Both approaches entail estimating the beam pointing
by differencing the three-dimensional position of the altimeter instrument and the laser-beam spot (or “footprint”) location
on the ground. Analytical assessments of the two approaches are discussed, along with recommendations for the ICESat pointing
determination calibration strategy.
Received: 28 April 2000 / Accepted: 6 November 2000 相似文献
36.
Amery冰架DEM及其海洋冰分布研究 总被引：1，自引：0，他引：1
Amery冰架是东南极最大的冰架。利用克里格插值法对Amery冰架地区的ICESat激光高度计数据进行空间插值,建立该地区的DEM。依据流体静力学平衡原理构建Amery冰架的冰厚度图,结合冰雷达测厚数据,获得了海洋冰的空间分布。结果显示Amery冰架下的海洋冰主要位于西北部,体积为2.38×1012m3,约占冰架总体积的5.6%,冰架最大厚度为230 m。 相似文献
37.
根据1975年地形图、1970s末至2013年19期Landsat（MSS、TM、ETM+）陆地资源卫星和20032009年ICESat卫星数据,以及近40年气象资料,对西藏佩枯错湖泊面积变化进行分析.结果表明,湖泊面积、湖泊高度变化波动较大,均呈减少和退缩趋势.19752013年间湖泊面积减少10.68 km2,减幅为3.79%.从空间动态变化来看,变化较明显的区域位于该湖的南岸和东北岸,南岸、东北岸湖岸线分别向北、向西南萎缩.20032009年湖面高度和湖泊面积均呈现出下降趋势,分别下降了0.17 m和4.4 km2.19992013年之间对该流域湖泊有影响的冰川变化分析显示,冰川呈现出退缩、面积减少趋势.数据显示冰川面积总共减少了17.17 km2,减少率为7.91%.自1971年以来,流域气温总体呈上升趋势,2000年以后升温显著.佩枯错43 a来降水量年际变化波动较大,年降水量呈减少趋势,总的来说降水量每10 a减少6.99 mm.虽然佩枯错属于降水和冰雪融水补给湖泊,但该流域湖面增减与周围冰川变化的关系并不明显,与温度变化呈负相关,而与流域内降水量呈正相关.综合分析表明,佩枯错流域湖泊变化与冰川退缩关系不密切,降水量是湖泊变化的主要原因. 相似文献
38.
目前,ICESat/GLAS是大尺度SRTM DEM精度评价的主要数据源.然而,现有的精度评价方法均忽略了2组数据的有效配准.为此,本文分析了数据配准前、后SRTM DEM整体精度差异,以及不同地形因子和土地利用类型对SRTM DEM影响程度.在此基础上,充分考虑SRTM DEM精度影响因素,分别借助多元线性回归(ML... 相似文献
39.
利用卫星资料反演区域冰川冰量变化的尝试——以祁连山为例 总被引：4，自引：1，他引：3
物质平衡是衡量冰川“健康”状况的最好方式,由于野外工作开展难度大,物质平衡观测仅局限于少数几条冰川上,限制了区域冰川物质平衡和冰量变化的评估.通过卫星高程数据可以监测区域冰川高程变化,进而可估算其冰量变化.利用SRTM和ICESat激光测高数据反演了祁连山冰川冰量变化,结果表明:21世纪初祁连山冰川处于物质亏损状态,年平均高程减薄(0.345士0.258)m,相当于(0.293土0.219)m w.e.,估算祁连山冰川年均冰量损失为(534.2±399.5)×106 m3 W.e..由于祁连山各冰川区相对独立,相隔较远,冰川规模普遍不大,且ICESat地面轨迹在中低纬度分布稀疏,使得结果的不确定性还很大. 相似文献
40.
结合机载、星载激光雷达对GLAS(地球科学激光测高系统)光斑范围内的森林地上生物量进行估测,并利用MODIS植被产品以及MERIS土地覆盖产品进行了云南省森林地上生物量的连续制图。机载LiDAR扫描的260个训练样本用于构建星载GLAS的森林地上生物量估测模型,模型的决定系数(R2)为0.52,均方根误差(RMSE)为31Mg/ha。研究结果显示,云南省总森林地上生物量为12.72亿t,平均森林地上生物量为94Mg/ha。估测的森林地上生物量空间分布情况与实际情况相符,森林地上生物量总量与基于森林资源清查数据的估测结果相符,表明了利用机载LiDAR与星载ICESatGLAS结合进行大区域森林地上生物量估测的可靠性。 相似文献