ALOS World 3D - 30m Ellipsoidal

<h3>Note: This version of the ALOS World 3D dataset is provided in a WGS84 ellipsoidal vertical datum. This is a non-standard version of the AW3D30 dataset that is often used for InSAR analysis. This dataset was converted from the orthometric version using the EGM96 geoid model available <a href=\"http://download.osgeo.org/proj/vdatum/egm96_15/\">here</a>. For additional conversion details feel free to <a href=\"http://www.opentopography.org/contact\">contact us</a>.</h3><br> <br> The <a href=\"http://www.eorc.jaxa.jp/ALOS/en/aw3d30/\">ALOS Global Digital Surface Model (AW3D30)</a> is a global dataset generated from images collected using the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) aboard the Advanced Land Observing Satellite (ALOS) from 2006 to 2011. As described by the <a href=\"http://global.jaxa.jp/\">Japan Aerospace Exploration Agency</a>: The Japan Aerospace Exploration Agency (JAXA) releases the global digital surface model (DSM) dataset with a horizontal resolution of approx. 30-meter mesh (1 arcsec) free of charge. The dataset has been compiled with images acquired by the Advanced Land Observing Satellite \"DAICHI\" (ALOS). The dataset is published based on the DSM dataset (5-meter mesh version) of the \"World 3D Topographic Data\", which is the most precise global-scale elevation data at this time, and its elevation precision is also at a world-leading level as a 30-meter mesh version. This dataset is expected to be useful for scientific research, education, as well as the private service sector that uses geospatial information.<br><br> <b>Version: </b>As of May 24th 2021 OpenTopography is supplying V3.2 (Jan 2021) from:<br /> <i>ftp://ftp.eorc.jaxa.jp//pub/ALOS/ext1/AW3D30/release_v2012_single_format/</i> <br />Data downloaded prior to May 24th 2021 was in format: May 2016: Global terrestrial region (within approx. 82 deg. of N/S latitudes) of Version 1 released (approx. 22,100 tiles) <br><br><b>Note:</b> JAXA provides two versions of AW3D30 created from the original 5-meter mesh using different downsampling methods: average (provided here) and median (not available from OpenTopography).

<h3>备注：</h3><br> <br> 本版本的ALOS World 3D数据集采用WGS84椭球垂直基准面。这是常被用于合成孔径雷达干涉测量（InSAR）分析的非标准AW3D30数据集。该数据集由正高版本通过EGM96大地水准面模型转换所得，转换相关资源可从<a href="http://download.osgeo.org/proj/vdatum/egm96_15/">此处</a>获取。如需了解更多转换细节，可<a href="http://www.opentopography.org/contact">联系我们</a>。<br><br> <a href="http://www.eorc.jaxa.jp/ALOS/en/aw3d30/">ALOS全球数字地表模型（AW3D30）</a>是一套全球数据集，其数据来源于2006年至2011年间搭载于先进陆地观测卫星（ALOS）上的全色立体测绘遥感仪器（PRISM）所采集的影像。据日本宇宙航空研究开发机构（JAXA）介绍：日本宇宙航空研究开发机构（JAXA）免费发布该水平分辨率约为30米网格（1角秒）的全球数字地表模型（DSM）数据集。该数据集由“大地”号（ALOS）先进陆地观测卫星采集的影像编制而成。本数据集基于当前最精确的全球尺度高程数据——“世界3D地形数据”的5米网格版本DSM数据集发布，作为30米网格版本，其高程精度同样处于全球领先水平。该数据集有望在科学研究、教育以及使用地理空间信息的私营服务领域发挥应用价值。<br><br> <b>版本： </b>截至2021年5月24日，OpenTopography提供的为V3.2（2021年1月发布）版本，数据来源地址为：<br /> <i>ftp://ftp.eorc.jaxa.jp//pub/ALOS/ext1/AW3D30/release_v2012_single_format/</i> <br />2021年5月24日前下载的数据格式为：2016年5月发布的第1版全球陆地区域（南北纬度约±82°范围内）数据集，包含约22100幅瓦片 <br><br><b>备注：</b> JAXA提供了两种基于原始5米网格生成的AW3D30版本，二者采用了不同的下采样方法：平均值法版本（本次由OpenTopography提供）与中值法版本（暂未在OpenTopography平台上架）。