In this case changing the z factor to 2 will multiply the input dem by 2 before computing hillshade. The zfactor adjusts the units of measure for the z units when they are different from the x,y units of the input surface. Then i open the dem terrain models dialog and select this raster layer, choose an output file and fill in values for scale and z. When we download digital elevation models dems in raster format, the. The existing arcgis tools typically do not work well with data in a geographic coordinate system i.
If double clicking on the msp file does not start the service pack installation, you can start the service pack installation manually by using the following command. The spatial analyst toolbar is added to your arcmap session. For example, if both elevation and dataset coordinates are meters and you want to exaggerate by a multiple of 10, the scaling factor would be the unit conversion factor 1. Doubleclick the msp file to start the install process.
Click customize toolbars spatial analyst on the main menu. In the symbology panel, next to render type, choose hillshade. The z factor is used to exagerate or reduce the altitude effect. The input dem is multiplied by the z factor before calculating shadows. We set the zfactor parameter based on latitude angular distance north or south of the equator. Right click on your hillshade layer and go to layer properties display and set transparency to 30%. However, the resultant hillshade seems to be vertically exaggerated. Focal statistics and the swiss hillshade spatial analyst. This is designed to be used as a backdrop for topographical, soil, hydro, land cover, or other outdoor recreational maps. After the hillshade is created, open its layer properties dialogue. Change the altitude to 35 degrees, azimuth to 300 degrees and z factor of 1. It is a qualitative method for visualizing topography. We need to enter a scale correction factor of 111120 in the scale ratio vert.
By default, a grayscale color ramp is used to display a hillshaded elevation model. Hillshade output example using hillshade for display. 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 example below has an azimuth of 315 degrees and an altitude of 45 degrees.
Add a point scene layer add an integrated mesh layer arcgis map image layer arcgis raster function service arcgis tiled layer arcgis vector tiled layer url blend renderer browse wfs layers change feature layer renderer change sublayer renderer colormap renderer control annotation sublayer visibility create a feature collection layer from a. A tinted hillshade is a combination of a hillshade applied to the terrain, fused to a colormap applied to the same terrain to represent elevation. Not setting the z factor correctly makes the hillshades look heavy or leaden. The hillshade result is scaled dynamically by adjusting the z factor using one of two options. Load the geotiff file into qgis raster load and rename the layer hillshade. If the x,y units and z units are in the same units of measure, the zfactor is 1. To apply vertical exaggeration, you must multiply the conversion factor by the exaggeration factor. The hillshade tool creates a shaded relief raster from a raster. The z factor parameter is in many spatial analyst and 3d analyst tools. This zfactor adjustment method is cumbersome to implement with. Ensure the zfactor is 1 because our x,y and z values are all in meters. By placing an elevation raster on top of a hillshade raster and adjusting the transparency of the elevation raster, you can easily create a visually appealing relief map of a landscape. Activity constant to store a zfactor conversion constant applied to the hillshade. Create great looking hillshaded maps in qgis ieqgis.
Right click the layer to open the layer properties window. This article points to a file gallery where the files are available for download. The surface area and ratio arcgis extension enables you to generate raster datasets of surface. I am having problems creating a hillshade from a mosaic dem i made with 10m usgs seamless data dems. The hillshade were created from these dems using the hillshade function in arcgis 9. You can either make a temporary hillshade for display only or you can make the output permanent for use in the future. When entering a file name for the output raster, the file extension determines what format the raster will be saved as. And if you increase the z factor, youll essentially be creating a display that exaggerates the heights of the surface. Light characteristics, verticalgeographical source will be determinant for the hillshade. Hillshade coming out totally wrong geonet, the esri. Not setting the zfactor correctly makes the hillshades look heavy or.
The simplest and most interactive is to use the image analysis window. In this tutorial, we are going to learn about how to create hillshade raster from srtm on arcgis 10. This extension offers some advantages over these existing tools in that. The input dem is multiplied by the z factor before calculating shadows, so a zfactor of 2 will give shadows as if the mountains were twice as high. And then the default z factor value that it has of one.
Using arcmap hillshade command to simulate 3 dimensional images. If the x,y units and z units are in the same units of measure, the z factor is 1. When performing a hillshade or slope function in arcgis, the z units are presumed to be the same as the horizontal x,y units. Hillshade renderers can adjust a grayscale raster usually of terrain according to a hypothetical sun position azimuth and altitude. I used an srtm dem to create a hillshade in qgis 2.
Altitude angle above ground and angle directionaspect of lightsource can. We set the z factor parameter based on latitude angular distance north or south of the equator. The scaleadjusted hillshade raster function template applies hillshading on the input elevation raster with a nonlinearly adjusted zfactor. It was fun and before i knew it i had prepared elevation models for seven more countries. Using the knowledge youve learned about arcgis, complete technical tasks such raster calculations and suitability analysis. If your xy units are in meters and z units are in feet, the zfactor would be 0. If the data is in a geographic coordinate system, change the z factor.
Home creating 3d visualizations in arcmap using hillshade. How to create hillshade from dem on qgis gis tutorial. For all the hillshades, the altitude was set at 45, the z factor at 1 and the output cell size at 10. Using arcmap or arccatalog your preference, load a base digital elevation model. Higher zvalues will result in a more exaggerated relief surface and, thus, in a more extreme shading. The zvalues of the input surface are multiplied by the zfactor when calculating the final output surface. Creating a hillshade a hillshade is a shaded relief raster created by using an elevation raster and setting an illumination source typically the sun at a userspecified azimuth the angular direction of the illumination source, in positive. These tools correctly handle latitude longitude data. Also, changing the settings for scale and zfactor does not have any effect on the resultant hillshade. Create a hillshade or slope using data in geographic coordinates summary.
A hillshade is a grayscale 3d representation of the surface, with the suns relative position taken into account for shading the image. The zfactor parameter is in many spatial analyst and 3d analyst tools. The z factor is varied based on scale so that a suitable hillshade is visible at all scales. For another example, if your vertical zunits are feet and your horizontal x,y units are meters, you would use a zfactor of 0. This function uses the altitude and azimuth properties to specify the suns position. If the vertical units are not corrected to the horizontal units, the results of. Generating a hillshade may take up to a minute depending on the size of your dem. Hillshade is a shaded relief from a surface layer considering the illumination source angle and shadows. Usgs hill shade base map service from the national map.
Create a hillshade raster of the base dem dem03, in this example using the spatial. Nonethis applies a linear adjustment by modifying the z factor according to the cell size, thereby accounting for altitude changes scale as the viewer zooms in and out. Displaying a dem with hillshadinghelp arcgis for desktop. The z factor adjusts the units of measure for the z units when they are different from the x,y units of the input surface. And what im going to do here is im going to rightclick on focal statistics and have it run that. When the dem or srtm data is rendered using hillshade, we will get the following. Creating a hillshade from mosaic dem geonet, the esri. We can display this data in qgis in various mode such as hillshade, multiband, singleband etc. 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. We can easily generate hillshade from srtm data in few clicks.
Function to calculate hillshade for a digital elevation model. Some years ago i prepared a hillshade model for tanzania. The hillshade function produces a grayscale 3d representation of the terrain surface, with the suns relative position taken into account for shading the image. I feel like it has something to do with the zfactor field in the hillshade dialog, but i have no idea what to set that to so i leave it as the default value of 1. The z values of the input surface are multiplied by the z factor when calculating the final output surface. When working with data in geographic coordinates, this is a problem because the linear distance of a degree of latitude varies. Learn a new method for displaying hillshades and elevation.
Arcgis has many useful tools for calculating slope, aspect, hillshade and curvature from dem rasters. University library, university of illinois at urbanachampaign. The hillshading is based on a solar altitude angle of 45 degrees, and solar aspect angle of 315 degrees. If the x, y, and zunits are all the same in feet, for example, the zfactor is 1. Not setting the zfactor correctly makes the hillshades look heavy or leaden. Setting the z factor parameter correctly arcgis blog.
Based on this other thread i used the equations to calculate for my area. Arcgis raster function service arcgis for developers. Dems for use in arcmap and other gis programs shows how to download. Dem or srtm data is a topography model with elevation information in it. Scale and z factor have no effect on hillshade analysis in.
Here, you can adjust the illumination with the altitude, azimuth, and zfactor through the. How to create hillshade raster from srtm on arcgis 10. Also the hillshade itself does not look right, it appears very grainy and small. The usgs shaded relief base map service from the national map was created with data from the 3d elevation program 3dep for large and medium scales 1. The hillshade for hawaii big island is in utm zone 5n, and the hillshades for the. Individual dem quads were first converted to a common datum, and vertical unit, and subsequently mosaicked in arcgis 9. I go to the spatial analyst tool hillshade and create the new hillshade layer, but the output is a grey screen in which you can view lines where the individual usgs dems boundaries were, not a hillshade. Refer to the esri mapping center blog setting the z factor parameter correctly for a list of z factor values. Learn more about how the hillshade algorithm works here. With a factor of 1 the default, a meter horizontal is the same as a meter vertical. If you did not select a hillshade in the previous step, rightclick dem insert hillshade. Derives slope and aspect in radias to calculate shading value between 0 and 255 using a given lighting angle and altitude. I have tried both options in qgis, analysis dem terrain models and terrain analysis hillshade.
Hillshading is a technique for visualizing terrain determined by a light source and the slope and aspect of the elevation surface. This value is often overlooked, but it is important to consider when creating a hillshade, because it has a significant impact on the appearance of the output. The zfactor is a conversion factor that adjusts the units of measure for the. This map portrays elevation as an artistic hillshade. It is not uncommon to perceive the output from hillshade as looking peculiar if the. In this article, we are going to focus on the hillshade. The z factor is a scaling factor used to convert the elevation values. The hillshade raster will be automatically added to arcmap. It is the number of ground x,y units in one surface z unit.
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