Digital Elevation Model (DEM), which could be a Digital Terrain Model (DTM) or a Digital Surface Model (DSM).

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36 views

Why QGIS Raster clipper does not work on reprojected layers?

I try to clip a hillshade raster and I get this error. The hillshade was the result of a reprojected DEM from WGS84 to WGS84UTM. When I to clip the hillshade or even the reprojected DEM, I get the ...
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1answer
35 views

What exactly does hill shade or Shaded relief , if performed on SRTM DEM will output?

Two questions actually. Does shaded relief or hill shade outputs mean "expelling of shadows"? For a vast country like India, how to prepare a map from SRTM DEM, which does not have any shadow ...
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1answer
17 views

DTM posting and resolution

When speaking about a DMS or a DTM, what is posting? And what is the difference between posting and horizontal resolution?
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2answers
91 views

How to properly get the slope from an ASTER DEM in QGIS?

I have inserter a raster dem layer from ASTER satellite and I want to get a raster that has the slope of the area. I use terrain analysis > slope but the output is so wrong. Why is that? here is the ...
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5answers
2k views

Definitive source for downloading DEM data

USGS has been moving towards serving data through The National Map Viewer. They have several WMServices through their website that serve elevation data to the public (hillshade & DEM). The ...
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1answer
40 views

Depressions in Texas DEM

I am working with the 10m DEMs and see some round depressions in Texas. I found this in two areas of about 12 sq km but do not have the tiles for the areas in between, so the area where I see this ...
3
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2answers
220 views

GDAL rotate DEM

Is it possible using any of the command line GDL tools such as gdalwarp, etc to perform a rotation of DEM data - a GeoTiff for example? Anyone know how to do this? UPDATE1 After clearing out ...
3
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1answer
3k views

Convert DEM to STL (3D Printer Format)

I have a DEM in ArcGIS 10.1 that I would like to get into STL format for a 3D printer. Does anyone know some software that will allow me to make this conversion? I have to use the STL format because ...
3
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1answer
181 views

Integrating DEM within kriging and other interpolation methods?

I would like to see the difference of including DEM in interpolation from without. Some studies on climate data interpolation suggest that interpolation performs better with DEM. How do I do this in ...
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13 views

DEM and r2stl() distorted models?

If I import a dem file into R and then call as.matrix() on it, I can access z values. I want to create a 3D model, but I'm getting strange results. Most of my dems are spiky and if they are smooth I ...
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1answer
63 views

QGIS Interpolation on Curved Grid (River DEMs)

Hi QGIS experts out there, I have an very hard task I want to do in QGIS (or another open source GIS program). I have point data for river bathymetry (depth). I have been creating digital elevation ...
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1answer
38 views

DEM files and r2stl()

In R The Volcano dataset has elevation values, but is not a DEM file. How can I convert my DEM files (from earthexplorer.usgs.gov) so that the I can access all the elevation values in a matrix (what ...
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58 views

Problem with Flow Direction in DEM

I have the following problem with Flow Direction Tool in my DEM and with such wrong calculated flow direction in the centre of DEM I am unable to delineate any watershed. What can I do?
4
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1answer
190 views

Flow direction generated for river is incorrect

I am trying to generate a hydrologic model and I can not really proceed on the next processes. I have this problem on generating flow direction. I have already executed fill sinks and the next is flow ...
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1answer
42 views

raster topo map with gaps to DEM

I'm trying to create a DEM from this raster map: I managed to clean all the shapes and text. I tried to write a program which finds the curve pieces and connects them. But, I realized that it is ...
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0answers
45 views

Managing or Reducing noise in a mosaic raster

I have created a raster with the Mosaic to New Raster tool from 3 separate rasters. However in my mosaic I have some consecutive pixels which seem to be the noise of the previous procedure. Is there ...
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1answer
44 views

Proof low deviations in DEM compared to point dataset

I am not sure how to achieve the following consistently: I have a regular distributed point dataset (surface elevations). From this I derived several DEM using QGIS IDW Interpolation method. Now I ...
3
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1answer
136 views

Creating constant slope DEM using ArcGIS Desktop?

I wanted to create a DEM of constant slope say 1/3000. How can I proceed in ArcGIS Desktop 9.3? The area may be 1000m x 1000m or any other as per convenience.
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0answers
37 views

How do I make a constant slope elevation model in arcMap? [duplicate]

I am currently working with ArcMap to develop an elevation model of a quarry showing how the terrain at the quarry site would look post-closure. One of the requirements is that the slopes placed along ...
0
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1answer
59 views

DEM data processing

I downloaded ASTER GDEM Tiles and mosacked them in ENVI. After that I exported the Mosaic in tiff format and I opening it in Arcgis, the image is gray all through but the pixels are showing correctly. ...
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4answers
1k views

Are there any open source tools to detect and fill sinks on a DEM?

Are there any open source or inexpensive tools to detect and fill sinks on a DEM? ArcGIS Spatial Analyst is just out of my price range.
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2answers
684 views

min and max values are not correctly calculated for DEM

I'm working with DEM in QGIS and need to know the min and max values of my data. In the Properties window, under the Metadata tab, the statistics section shows such values. However, I usually find ...
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2answers
60 views

Where do I get Elevation Data for Scotland?

So I am new here and I arrived here because I have been searching for quality elevation data for the entire Scotland but I have not succeeded yet. Kindly help if you know where to get the data Raster ...
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2answers
73 views

Simulate sun movement

Are there any software packages/solutions that allow me to simulate the movement of sun or direction of sunlight over a period of time (e.g. 24 hours)? My purpose is to determine the regions cast in ...
2
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1answer
69 views

Unable to Produce Hillshade

I have been trying to create a hillshade using DEM data, however, regardless of the scale and z values I use the output is all black. I accessed the DEM data from a government source and clipped it ...
2
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1answer
80 views

How to calculate point(or XY) for Start point of Slope and Endpoint of Slope along the Section line on DTM

How to calculate point(or XY) for Start point of Slope and Endpoint of Slope along the Section line on DTM. for instance
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0answers
15 views

edit tif from dem by polygon selected in arcmap

i need to edit the tif of dem generated from agisoft photoscan using the arcmap to do a slope map from area. how to select the pixels and change their altimetry information mainly in trees locations ...
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1answer
7k views

Which is better, DEM or Triangles (TIN/Terrain)

Which is better DEM or TIN? What are the benefits/negatives of each?
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41 views

Surface Volume 3D Analyst tools

I'm using Surface Volume tool (ArcGIS 10.3) to calculate volume of air from a valley. I delimited my DEM (clip tool) and choose Below as plane reference with 603 m as height. The DEM is projected in ...
2
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1answer
35 views

How do I count the number of cells which can see each cell in QGIS

For each cell in a DEM I'd like to count the number of cells which can see it (i.e. direct line of sight) - Can anyone explain how to do this in QGIS? Thanks,
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5answers
2k views

How to aquire a topographical map of Britain?

First of all, let me say that I know next to nothing about GISs. I'm trying to find / make / aquire a topographical map of britain. I want to use it as a height map in Dwarf Fortress so it needs to ...
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0answers
18 views

What is the best option for web elevation profile using in-house DEM?

ArcGIS Server requires the advanced license for the 3D analysts extension. Are there any open source options? Thanks
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1answer
138 views

Create a DEM with 1 foot contours

I have Lidar data which contains multiple .las files for an entire quad. I have figured out which .las is the area I am looking for. I was told the data is in 1.4 meter resolution and would work to ...
2
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1answer
68 views

Make a ground mask raster with the Greater Than tool

I'm trying to see if I can replicate the Esri solar suitability site example from this article. I fail on the creation of the binary ground raster. I have made a Bare Earth raster from LiDAR ground ...
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0answers
75 views

Mosaic to New Raster: Problem with min and max values

I have to combine several DEM rasters into one from this source: http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp, so I use Mosaic to New Raster tool. I set up the tool: 1) I input the rasters (all ...
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1answer
3k views

Download new SRTM 30 meters

I read about the new version of the digital elevation model at 30 meters (SRTM 30 meters), but I can not find from were I can download it. some sources: ...
4
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2answers
289 views

What is the source of horizontal and vertical striping in USGS DEMs?

When processing 30m and 10m DEM data downloaded through the National Map Viewer from the National Elevation Dataset, we noticed horizontal and vertical striping not only in the produced results, but ...
5
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2answers
109 views

Retrieving heights of buildings using remotely sensed data (except lidar)

How can I get the height values of buildings from a certain sector a city without going into the field to collect data? Is there anyway to do via satellite imagery, SRTM, ASTER GDEM or any DEM for ...
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0answers
167 views

Assessing Flood Hazard Risk Zones using DEM

My Question: What is the best effective way to quickly estimate flood hazard risk areas using DEM data? Ideally I am looking for guidance to move forward and perform this process over large areas ...
8
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2answers
956 views

What is the smallest contour interval possible when derived from a DTM?

I am converting a 2m DTM to contours, and would like to have the smallest interval possible. Is there a theoretical limit, or even a rule of thumb for defining contour intervals based on the ...
0
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1answer
59 views

Is there a difference between the two sets of QGIS terrain analysis tools?

Is there a difference between Raster/Terrain Anaylsis and the same features in Raster/Analysis/DEM (Terrain Analysis)? The two appear to do the same types of computations; are they the same or is ...
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0answers
36 views

How to ignore certain values when creating profile graph in ArcGIS for Desktop?

I have a statewide DEM I am trying to create a profile of, however the DEM has some areas of widely varying size (bodies of water) where data was not collected and these areas were all filled by my ...
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0answers
25 views

automatic extraction of dtm using grass gis

i have generated dsm using erdas lps tool which is in img format. i want to import this file in grass gis and extract dtm. can you please tell me how to input the data , in which format it should be, ...
8
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4answers
6k views

How to use SRTM Global DEM for Slope calculation?

I have downloaded SRTM GDEM (~90 km resolution). I am using ArcGIS 10. I have tried to use spatial analyst to compute for slope. However, I can not compute for the slope. The output values has only ...
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0answers
44 views

How to show elevation on mouse hover in QGIS?

I've got a DEM layer and would like to have the status panel in the bottom display the elevation in addition to the mouse coordinate. Can that be done? Using QGIS 2.6.1
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0answers
34 views

Library to render 3D DEM?

I am implementing a C++ application to generate DEMs from LAS files, and I want to show a 3D visualization of the DEM (show the terrain model, height differences using colors, contour curves...) Is ...
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2answers
71 views

Building DEM of large areas

I am putting together a compilation of 1/3 arc second, and 1/9 arc second DEM data for essentially all of southeastern Oregon in ArcGIS. This surface would be used for geomorphological and geological ...
1
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1answer
68 views

Displaying DEM with real elevation values in ArcGIS Desktop?

I am trying to create a DEM with hillshading map in ArcGIS Desktop 10, but I'm getting the result with scale values between 0 and 254. How can I display the scale with the real elevation values? ...
4
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1answer
60 views

Calculation of surface derivatives at the edge of the raster

I was wondering how does ArcMap10.2 calculate surface derivatives (slope, aspect) at the edge of the raster, since the Horn algorithm is used and uses the 8 neighboring pixels around each pixel. When ...
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2answers
36 views

Not able to load a DEM raster into Spatialite

I am using Spatialite to store a DEM raster with terrain values (GMTED2010 from Nasa). To be more precise, I am using the version: spatialite_gui-1.7.1-win-x86.zip plus rasterlite_load ...