共查询到20条相似文献,搜索用时 31 毫秒
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《The Photogrammetric Record》2003,18(103):190-190
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随着数字摄影测量技术、LiDAR和InSAR等测绘高新技术的发展,数字高程模型在数据获取、生产技术和工艺等方面较以往发生了很大变化。2001年首次发布的行业标准《基础地理信息数字产品1:100001:50000数字高程模型》在很大程度上已经不能反映当前我国DEM生产的实际状况,有必要对该标准进行修订。深入分析和研究美国、英国、加拿大等国DEM相关标准,并充分考虑我国测绘生产的实际状况,对该标准的相关内容和技术指标进行修订,提高标准的现势性,保证相关标准之间的协调性和完整性,能更好地满足测绘生产和用户的实际需要。 相似文献
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Since its introduction in 1993, the LAMBDA method has found widespread use across the world. The method has been employed
in many geodetic and navigation applications, with lots of satisfied users. Independent tests show that it is considered the
best method for integer carrier phase ambiguity resolution available. But every now and then we still notice some misunderstandings
concerning the principles and potential of the method. In this contribution we will briefly summarize the principles underlying
the LAMBDA method, go into some of the frequently asked questions on the LAMBDA method and try to clarify some of the existing
misunderstandings.
Electronic Publication 相似文献
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康贵祥 《测绘与空间地理信息》2018,(7):201-204
随着社会不断发展,新生事物不断增多,针对目前执行的《1∶5 000 1∶10 000地形图图式》地形图符号缺失、原有地图符号的设计与计算机制图相矛盾的事实,本文将地形图图式、符号与计算机制图的特点相结合,对地形图图式、符号的修改及创新发展,提出了一些个人见解。这些建议增大了地形图表示的信息量,增强了地形图表示的形象性、准确性、实用性。 相似文献
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ETWatch中的参数标定方法 总被引:3,自引:2,他引:1
使用遥感手段估算区域范围的蒸散量一直是热红外定量遥感的研究热点。ETWatch是用于流域蒸散遥感监测、针对遥感应用而设计的集成框架。方法集成了具有不同应用优势的遥感蒸散模型,并以Penman-Monteith方法为基础建立时间扩展方法,利用气象数据与晴好日的通量遥感估算结果,获得逐日连续的蒸散分布图。所生成的从流域级到地块级的数据产品能动态反映区域蒸散发的时空变化规律。为深入了解遥感蒸散量估算中的不确定因素,本文将其通量计算过程分为地表参数获取(以地表温度为主)、日净辐射、蒸发比等环节与地面数据进行对比和逐项的标定。并分别采用地表阻抗扩展法和蒸发比不变法进行了时间插补的对比研究。利用站点地面观测资料对蒸散遥感监测产品的验证表明,在全年内模型蒸发比结果与实测的时段平均蒸发比的相关系数可达到0.7左右,在更长的时间尺度上(月、季、年)平均百分比误差可以减小到10%以下。 相似文献
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Edinburgh Castle is an ancient monument situated on a basalt crag which has steep cliffs falling away on three of its sides. Periodically, remedial measures have to be carried out on these cliffs by engineering geologists in order to stabilise loosened parts of the surface and thus prevent rock falls occurring. The rock structure on the sheer north-facing cliff is currently being studied to determine the extent of work required to ensure its stability. Before such a study could proceed satisfactorily it was necessary to obtain a large scale, contoured survey of the face and this has been achieved by terrestrial photogrammetric methods. Stereoscopic photography was taken with a Wild RC5A wide angle camera pointing horizontally, being specially mounted on its side in the elevated bucket of a Simon hydraulic platform, positioned 17 metres above ground level at a distance of 100 metres from the rock face and at eight successive locations in West Princes Street Gardens. The elevation was plotted with a Zeiss Stereoplanigraph C8 at a scale of 1 : 50 with contours (with respect to a vertical datum) at horizontal intervals of 250 mm. 相似文献