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

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8 views

Morphometric analysis tutorial [closed]

I want to analyze morphometric parameters such as drainage density,stream order,bifurcation ratio etc of a small basin area. Here I want to use SRTM dem and arcgis tool. Please share if any one have ...
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20 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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15 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, ...
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1answer
45 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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27 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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19 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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1answer
40 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? ...
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1answer
34 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
53 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 ...
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20 views

DEM data for Borneo island (higher resolution data than SRTM/ASTER GDEM for South East Asia?)

I am looking for high resolution DEM data for Borneo island and am especially interested in Sarawak. Currently I only found SRTM and ASTER GDEM data (normal products from NASA REVERB ...
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1answer
38 views

SRTM DEM with 16 bit signed pixel type changes to 32 bit float when creating slope/aspect/curvature

I have mosaiced 8 SRTM DEM tiles in order to get one raster layer of elevation. When I use "Mosaic to New Raster" tool I set as a pixel type format "16 bit signed" because this is the format that SRTM ...
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1answer
32 views

QGIS 2.6.1: “no enhancement” option not working on DEMs

When I import DEM raster layers and try to change the contrast to "no enhancement" I get a blank white image in the map window. Changing "black to white" to "white to black", the map remains a blank ...
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22 views

Displaying a Digitial Elevation Model using GRASS GIS draped by an RGB Raster

I have the following: Digital Elevation Model from SRTM LANDSAT Imagery from the same area I wish to display the DEM draped with the raster band combination (3,2,1) using GRASS GIS. My ...
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1answer
39 views

What is a DTM in Grid format?

A client asked us for a group of files of DTM in Grid Format. And my question is, what is this DTM in Grid format? O maybe its same of DEM? Is it possible to convert from DEM gray scale format to ...
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1answer
26 views

Changing the Axis on a Profile Graph

I'm working on a map with forest trails and I want to get an elevation profile of them all individually. I have gone through and interpolated the trail layer with a DEM so that I can use the 3D ...
3
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1answer
67 views

DEM creation with C++ application

I am implementing a C++ application that must produce DEMs from LIDAR data. I am following the next workflow: Write .las files from lidar data. Use PCL algorithms to transform/filter the point ...
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1answer
75 views

Which method is better for display terrain in OpenLayers?

I want to display terrain in OpenLayers. So, I tried to use dem(.img) and convert it to dem(.jpg) on QGIS. But, the effect is very bad. My expected effect is (This picture is captured from google ...
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1answer
57 views

Correcting for local topography in calculating TRI from DEM in ArcGIS

I'm currently investigating the use of different equipment in calculating TRI from elevation data using ArcGIS. From the methods available ...
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1answer
66 views

How to add image(.jpg) to OpenLayers?

This is my website for test: http://www.cv.nctu.edu.tw/shapefile-js-openlayers/ol_simple.html My dem data is (.jpg). var inProj = new OpenLayers.Projection('EPSG:3826'); var outProj = ...
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1answer
23 views

gdal_grid - fails to find layer and field

I'm using gdal_grid for the first time and get this issue: gdal_grid -zfield field_3 -l layer0 OLEX-LAT-190952014.vrt OLEX-LAT-190952014.tiff ERROR 1: Failed to find layer 'layer0' on datasource ...
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0answers
20 views

How to resample a DEM from GCS to UTM with respect to reprojection bounds parameter?

When reprojecting a DEM (e.g., SRTM-derived 1-arc DEM) using PCI Geomatica for example, to constrain pixel size and maintain a square pixel you can either change the image extent or the number of ...
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44 views

How to do a flood simulation without flooding the whole area and covering surface structures (with DEM)?

I have a high resolution DEM and want to do a flood simulation starting at a river. My hope is that the water runs into historical (now dry) river channels (in which I'm interested in) at first and ...
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1answer
39 views

GeoserverTerrainProvider plugin displays faults in elevation tiles

I try to display elevation data using the triple Geoserver/Openlayer3/Cesium. It seems I have the same problem than http://stackoverflow.com/questions/25936968 and for now, I can not get a working ...
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3answers
54 views

How to resample a 30m DEM to a 100m slope raster properly?

I need to resample a 30m DEM to a 100m slope raster. Do I just resample the 30m DEM directly to the 100m slope raster? or, do I convert the 30m DEM to a 100m DEM and then create a 100m slope raster ...
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4answers
66 views

How to calculate RMSE, skewness, and kurtosis of raster image?

I'm doing a project to analyze the impact different interpolation techniques plays on DEM accuracy. In order to do so, I need to calculate the RMSE, skewness, and kurtosis. I have: an original ...
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2answers
111 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? Would I be better off converting (with gdal_translate) the ...
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1answer
30 views

How to decrease elevation values of DEM using open source GIS sotware? [closed]

I am newbie in QGIS, but I was wondering how to decrease elevation dem DEM using QGIS? Can QGIS do that? Or anyone of you can tell me any open source GIS software to perform that?
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29 views

aster georeference proplem

i have 2 dems raster layers and i want to georeferencer the first dem raster layer with the another(second) dem raster layer,because the first dem raster layer has wrong coordinates and the second dem ...
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33 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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3answers
47 views

Where can I download a free DEM for Scotland, UK?

I need a DEM file for Scotland, UK. Do you know where I can get it from for free? I need to create a watershed for an area of study. Thanks
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1answer
19 views

Raster Files Sizes from Point Data Extremely Different

Using ArcGIS 10.1. I created rasters from several groups of point rasters using the Point to Raster tool. All of the points groups are similar size and extents. The first group of points had a file ...
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2answers
212 views

Burning road network into DEM?

Does anyone have any suggestions for burning a road network into a DEM? I have a python script written up for this executing this in ArcMap, but I would love to hear if anyone knows of any freely ...
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2answers
32 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 ...
3
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1answer
40 views

Convert Whitebox .dep to ArcMap DEM .tiff?

I am having difficulty converting my whitebox raster float file to an ArcGIS raster file in ArcMap 10.2.1 I followed the protocol outlined at: ...
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0answers
72 views

How to extract elevation values at line start and end points from a DEM?

I am new to the whole gis-experience and need your help working with QGIS. I have: DEM raster with heights (3d) line-shapefile which contains the rivers (2d) I need: heights for "start" and "end" ...
2
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1answer
32 views

Disable Mosaic Overview Information When Using Identify Tool

I have a created mosaic datasets using elevation data. When I add this data to ArcMap and use the identify tool it brings up information about both the footprint and image. At full extent the ...
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2answers
80 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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2answers
65 views

ArcGIS, mosaic first or calculate first

I'm working a set of 30meter DEMs (~40 DEMs) for New England. I've seen a lot of debate on whether to work with (A) the individual DEMs first, and then mosaic the final raster calculations together, ...
3
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1answer
113 views

How to subtract out the slope (in general) of a DEM?

I'm searching for a solution process to subtract out the slope of a DEM like this: I have a high resolution DEM and want to reconstruct historical/old/not active parts of a river. The problem is ...
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1answer
66 views

mosaic dem with multiple coordinate systems

I'm sure this is a basic question, but I'm struggling to mosaic multiple DEMs (~40) into one large raster. The DEMs are 30m NED rasters from the NRCS data gateway, for the New England region. They are ...
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0answers
97 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 ...
3
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0answers
59 views

DEM from contours

I have problem to create a DEM from contours. I know it is very simple but I can not make it work. I tried everything but nothing has happended! The shapefiles I've got are a con_lin and a con_pol ...
5
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0answers
78 views

Extract DEM and DTM information from LIDAR image using E-Cognition

I´m trying to extract DEM and DTM from a LIDAR file. I just rasterize the image but then I don´t know which algorithm I need to apply to obtain the DEM and DTM information in different models to be ...
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0answers
21 views

findind depression in cloud point and dtm

I would like to find temporary moist areas based on terrain surface shape (depression) directly from cloud point data (ALS) and DTM. Could you help me to find some tools or algorithm to solve the ...
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3answers
87 views

Where can I find open source bulk US DEM or imagery?

I am looking to create terrain hillshading for my maps that contain a small region of the US. I intend to show about eight to ten states at a time (at about ~1:5,000,000 scale). It has been some ...
3
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1answer
79 views

how to extract elevation data using a DEM

I have digitized an LULC layer from satellite imagery, now I want to extract the elevation data from it. I have obtained DEM images from SRTM amd ASTER. How do I proceed?
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2answers
79 views

downloading DEM for free

I need to download a DEM in WGS format for Nepal ( around 86 degrees longitude and 27 degrees latitude), that can be exported to a GIS as raster for analysis. Does anyone know of any good, free data ...
3
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1answer
50 views

Relocating & resizing complex shapefile with OpenSource Software

(please excuse my poor english) I do have a polygone shapefile of an archaelogical site with elevation data of 10cm steps and I dont get hands on the raster data as it was collected by the drone. My ...
3
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2answers
105 views

How can I smooth or resample a DEM to find steep roads?

I am trying to find sections of road with steep gradients. My process is: pull a linestring from Openstreetmap data resample it to create a point every 10 metres look up the height data for each ...
2
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1answer
59 views

Problem or ERROR in converting from raster to vector!

I wonder if anyone could help me out, i am kind of a beginner at QGIS. I´ve built a DEM for a project that i am developing than i´ve made the slope raster with the terrain analysis,it seemed that ...