Landsat GLS Panchromatic

This layer includes Landsat GLS panchromatic imagery for use in visualization and analysis. This layer is time enabled and includes a number of panchromatic renderings on demand. The layer includes Landsat 7 ETM+, Landsat 5 TM, and Landsat 4 imagery at 15m. Geographic Coverage World-wide imagery coverage. Temporal Coverage This imagery layer includes data from epochs 2010, 2005 and 2000. Analysis Ready This imagery layer is analysis ready with Top of Atmosphere (TOA) correction applied. The TOA reflectance values (ranging 0 – 1 by default) are scaled using a range of 0 – 10,000. The scale is equivalent to other TOA reflectance products, including those provided by the USGS. Image Selection/Filtering Newer images are displayed by default on top. The entire archive is accessible via custom filtering. A number of fields are available for filtering, including Acquisition Date, Estimated Cloud Cover, and Product ID. By setting the filter to Best is lesser than QQQQ one can control to see the best N scenes, where QQQQ=N*1million. NOTE: Turning off all filters, and loading the entire archive, may affect performance. Visual Rendering Default layer is Panchromatic with Dynamic Range Adjustment (DRA). The DRA version of each layer enables visualization of the full dynamic range of the images. Rendering (or display) of band combinations and calculated indices is done on-the-fly from the source images via Raster Functions. Various pre-defined Raster Functions can be selected or custom functions can be created. Other Layer Usage Notes... Overviews exist with a spatial resolution of 300m and are updated weekly based on the best and latest imagery available at that time. To work with individual source images at all scales, either use the ‘Lock Raster’ functionality or add a query filter to restrict the display to a specified image or group of images. NOTE: ‘Lock Raster’ should only be used on the layer for short periods of time, as the imagery and associated record Object IDs may change daily. Images can be exported up to a maximum of 2,000 columns x 2,000 rows per request. This ArcGIS Server dynamic Imagery Layer can be used in Web Maps and ArcGIS Desktop as well as Web and Mobile applications using the REST based Image Services API. WCS and WMS compatibility means this imagery can be consumed as WCS or WMS services. Landsat Web App via Unlock Earth's Secrets. Data Source Landsat imagery is sourced from the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA). Data is hosted by the Amazon Web Services as part of their Public Data Sets program. Users can access full scenes from Landsat on AWS, or alternatively access LandsatLook to review and download full scenes from the complete USGS archive. The Global Land Survey includes images from Landsat 1 through Landsat 7. Band numbers and band combinations differ from those of Landsat 8, but have been mapped to the most appropriate band as in the above table. For more information about the Global Land Survey, visit GLS.本图层包含Landsat GLS全色影像，可用于可视化与分析工作。本图层支持时间维度检索，同时包含多种按需生成的全色渲染成果。 本图层包含分辨率为15米的Landsat 7 ETM+、Landsat 5 TM及Landsat 4影像数据。地理覆盖范围：全球全域影像覆盖。时间覆盖范围：本影像图层涵盖2010年、2005年与2000年三个时期的影像数据。 分析就绪性：本影像图层已完成大气顶部（Top of Atmosphere, TOA）校正，可直接用于分析。其TOA反射率数值默认范围为0至1，现通过0至10000的区间进行缩放，该缩放标准与美国地质调查局（USGS）提供的同类TOA反射率产品保持一致。 影像选择与过滤：默认情况下，较新的影像会置于图层顶部显示。用户可通过自定义过滤条件访问完整档案库，支持的过滤字段包括获取日期、估计云量及产品ID等。通过设置过滤条件为「最佳值小于QQQQ」，可控制仅显示最佳的N景影像，其中QQQQ等于N乘以1000000。注意：关闭所有过滤条件并加载完整档案库可能会影响系统性能。 可视化渲染：默认图层为应用了动态范围调整（Dynamic Range Adjustment, DRA）的全色影像。各图层的DRA版本可实现影像全动态范围的可视化展示。波段组合与计算指数的渲染（或显示）可通过栅格函数（Raster Function）从源影像实时生成，用户可选择多种预定义栅格函数，或自行创建自定义函数。 其他图层使用注意事项：本图层已生成空间分辨率为300米的概览图，每周会根据当时可获取的最优最新影像进行更新。若需在任意缩放级别下查看单个源影像，可使用「锁定栅格（Lock Raster）」功能，或添加查询过滤器将显示范围限制为指定单景或一组影像。注意：「锁定栅格」功能仅可短期使用，因为影像及关联记录的对象ID可能每日都会发生变化。单次请求导出的影像最大尺寸为2000列×2000行。本ArcGIS Server动态影像图层可应用于Web地图、ArcGIS Desktop，以及基于REST影像服务API开发的Web与移动应用程序。该图层支持WCS与WMS协议，可通过WCS或WMS服务进行影像消费。可通过「Unlock Earth's Secrets」平台访问Landsat Web应用。 数据源：本Landsat影像数据来源于美国地质调查局（U.S. Geological Survey，简称USGS）与美国国家航空航天局（National Aeronautics and Space Administration，简称NASA），由亚马逊云服务（Amazon Web Services，简称AWS）作为其公共数据集计划的一部分进行托管。用户可从AWS上获取完整的Landsat景数据，或通过LandsatLook平台查看并下载USGS完整档案库中的全景影像。全球土地调查（Global Land Survey，简称GLS）数据集包含Landsat 1至Landsat 7的影像数据。其波段编号与波段组合与Landsat 8存在差异，但已映射至上表中最适配的波段。如需了解全球土地调查的更多信息，请访问GLS官网。