R10-AK-Kenai-CanopyCoverPopUp

Terrain-related imagery are primarily derived
from Lidar, stereoscopic aerial imagery, or Interferometric Synthetic Aperture
Radar datasets. Consequently, these derivatives inherit the limitations and
uncertainties of the parent sensor and platform and the processing techniques
used to produce the imagery. The terrain images are orthographic; they have
been georeferenced and displacement due to sensor orientation and topography
have been removed, producing data that combines the characteristics of an image
with the geometric qualities of a map. The orthographic images show ground features such as roads, buildings,
and streams in their proper positions, without the distortion characteristic of
unrectified aerial or satellite imagery. Digital orthoimages produced and used
within the Forest Service are developed from imagery acquired through various
national and regional image acquisition programs. The resulting orthoimages can
be directly applied in remote sensing, GIS and mapping applications. They serve
a variety of purposes, from interim maps to references for earth science
investigations and analysis. Because of the orthographic property, an orthoimage
can be used like a map for measurement of distances, angles, and areas with
scale being constant everywhere. Also, they can be used as map layers in GIS or
other computer-based manipulation, overlaying, and analysis. An orthoimage
differs from a map in a manner of depiction of detail; on a map only selected
detail is shown by conventional symbols, whereas on an orthoimage all details
appear just as in original aerial or satellite imagery.This record was taken from the USDA Enterprise Data Inventory that feeds into the https://data.gov catalog. Data for this record includes the following resources: ISO-19139 metadata ArcGIS Hub Dataset ArcGIS GeoServiceFor complete information, please visit https://data.gov.

地形相关影像主要源自激光雷达、立体航空影像或干涉合成孔径雷达数据集。因此，这些派生数据继承了母传感器和平台及其生成影像所采用的处理技术的局限性和不确定性。地形影像为正射影像；它们已进行地理参照，并消除了由于传感器朝向和地形引起的位移，从而产生了结合图像特性与地图几何特征的综合性数据。正射影像展示了地面特征，如道路、建筑物和溪流等，处于其正确位置，避免了未正射的航空或卫星影像特有的畸变。美国林业局内部生产和使用的数字正射影像是由通过各种国家和区域影像获取计划获取的影像开发的。生成的正射影像可直接应用于遥感、GIS和制图应用。它们服务于多种目的，从临时地图到地球科学研究和分析的参考资料。由于正射性质，正射影像可以像地图一样用于测量距离、角度和面积，且比例尺在所有地方保持恒定。此外，它们还可以用作GIS或其他计算机基础上的地图层，进行叠加、操作和分析。正射影像在细节描绘方面与地图不同；在地图上，仅通过传统符号展示所选细节，而在正射影像上，所有细节均与原始航空或卫星影像一样呈现。此记录来自为 https://data.gov 目录提供数据的美国农业部企业数据目录。此记录的数据包括以下资源：ISO-19139元数据、ArcGIS Hub数据集和ArcGIS GeoService。欲获取完整信息，请访问 https://data.gov。