The zfactor is a conversion factor that adjusts the units of measure for the. Create a hillshade raster of the base dem dem03, in this example using the spatial analyst tools. If the z units of the data being used are feet, first use the raster calculator to multiply the raster by the conversion factor 0. The zfactor is a conversion factor that adjusts the units of measure for the vertical or elevation units when they are different from the horizontal coordinate x,y units of the input surface. The hillshade tool creates a shaded relief raster from a raster. The hillshade raster has an integer value range of 0 to 255. Configure the options for rendering, then click apply hillshade. The zvalues of the input surface are multiplied by the zfactor when calculating the final output surface. Arcgis has many useful tools for calculating slope, aspect, hillshade and curvature from dem rasters. The surface area and ratio arcgis extension enables you to generate raster datasets of surface. Open hillshade, hillshade window is appears select elevation layer and output layer, output format default is geotiff is ok, type z factor 300. Hello, i have a question about z factors and how to use them within a slope analysis and hillshade function.
It is the number of ground x,y units in one surface zunit. In this case changing the z factor to 2 will multiply the input dem by 2. I understand that the z value has to be converted to degrees using a z factor of. The zfactor parameter is in many spatial analyst and 3d analyst tools. Not setting the zfactor correctly makes the hillshades look heavy or leaden. Here we present several techniques which combine hillshade with other relief data layers derived from dem and. Relief visualization techniques using free and open source gis tools.
Basic visualization of lidar digital elevation models using arcgis. The zfactor is a scaling factor used to convert the elevation values for two purposes. The input dem is multiplied by the z factor before calculating shadows. These values will be processed with calculations for slope and aspect to determine the final hillshade value for each cell in the output raster. Hillshade one direction 315 degrees top and hillshade one direction 45 degrees bottom comparison of popular gis software by availability of blending modes colour hypsometric tint with two. It is not uncommon to perceive the output from hillshade as looking peculiar if the. Pdf relief visualization techniques using free and open. Setting the z factor parameter correctly arcgis blog. Convert the elevation units such as meters or feet to the horizontal coordinate units of the dataset, which may be feet, meters, or degrees. The arcgis software suite has many useful capabilities for handling geospatial data including. Ensure the zfactor is 1 because our x,y and z values are all in meters. Home creating 3d visualizations in arcmap using hillshade. This zfactor adjustment method is cumbersome to implement with latitude longitude. Generally, hillshade dems are clearer if the basic elevation layer is multiplied by 2 or 3.
If the x,y units and zunits are in the same units of measure, the zfactor is 1. Determine what the middle latitude of the area of interest is. The standard format for elevation data in gis is a digital elevation model dem in raster format. If the model shadows option is disabled unchecked, the output raster only considers local illumination angle. Using arcmap hillshade command to simulate 3 dimensional images. This zfactor adjustment method is cumbersome to implement with latitudelongitude. If you add appropriate or correct zfactor to your dem while creating hillshade, you can avoid too much contrast in the hillshade and too much bumpy in the flat areas. The illumination source is considered to be at infinity. The zfactor adjusts the units of measure for the zunits when they are different from the x,y units of the input surface. By default, a grayscale color ramp is used to display a hillshaded elevation model. Specific azimuth and altitude angles are set and a zfactor to convert z units in feet to meters. To calculate the shade value, first the altitude and azimuth of the illumination source are needed. Hillshadeslope analysis and z factors geonet, the esri.1424 5 192 1155 320 754 782 183 956 368 164 473 990 845 794 668 118 251 1663 336 696 1563 711 1455 840 1112 139 616 688 767 377 1031 1186 1029 560 1092 659 405 1436 1287 827 899 1306 134 829 843