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

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218 views

Error 5 Pixel type must be FLOAT32

I am trying to create a DEM from topographic contours vector. I have already sucessfully created a raster using the interpolation plugin. Firstly, I don't know why or how to ccontrol the output ...
2
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0answers
52 views

Extracting DEM from IFSAR

i have this IFSAR data (.img) and i dont know where to start. how do i extract DEM from this data? Do I need to go through a Remote Sensing software (ERDAS or ENVI) or i can simply use ArcGIS? and how ...
2
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1answer
48 views

Resolution of NED (National Elevation Dataset)

I downloaded some DEMs from the USGS with a resolution of 1/3 degrees for different areas in the US. Now I am looking at the files and saw that all DEMs have the same number of columns and rows. I ...
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0answers
40 views

How do I reduce contour intervals (i.e. from 50m contours to 10m contours) without using DEM?

I have shapefiles (lines) of contours having 50m intervals. How can I reduce the intervals to 10m without first converting the 50m contours to DEM?
2
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1answer
265 views

Gdal/QGIS resampling asc file

I have a DEM (.asc) file with a resolution of 1000 meters per pixel. Therefore the file has a lot of columns and rows. I would like to chance the resolution per pixel from 1000 to 3000 meters per ...
9
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2answers
157 views

Cleaning blocks pattern from urban LIDAR (blocks uplifted from streets)

We have a 1-meter LIDAR DEM from a city. A small subset can be downloaded from this link: This screenshot shows raw DEM with gray palette (darker belts are streets, and greyish and whitish ...
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0answers
137 views

Creating a 3d terrain model using a DEM raster file

i have a DEM Raster file and i would like to create a 3D Terrain Model using ArcScene. Is this possible, if yes, how? Thanks.
2
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1answer
69 views

las2dem issue - while generating a DEM raster cells with no data are being generated

Anyone has an idea where these lines (with no elevation data) come from? They are generated while using the las3dem tool from LAStools. What needs to be done to avoid this? The raw data (.las file) ...
2
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0answers
39 views

How can I manipulate the number of points visible according to scale?

I've gotten trillions of points extracted from a DEM and they are to be labelled. It's fine at scales such as 1:500 but it gets too cluttered especially if I need to make maps of this with scales up ...
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42 views

Extracted Contours from DEM translated in QGIS for certain intervals

I created a DEM from several point files in QGIS. Both of these line up well with the remaining data in my file (ie cadaster, aerial imagery, etc). I wanted to generate 2m contours from the DEM ...
4
votes
1answer
64 views

Curvature computation for different scales

I would like to assess terrain curvature, i.e. the 2nd derivative of a DEM, on different scales. The most common approach to curvature seems to be the one suggested by Zevenberg (1987) where a ...
2
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2answers
96 views

convert DTM txt file in geoTiff file

I have a DTM file, txt format, I would like to convert it into GeoTIFF, how can I do with the software grass? thanks ncols 1329 nrows 1152 xllcorner 1693884 yllcorner 5080341 ...
1
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1answer
109 views

Digital Elevation Model Resolution

While I creat flood areas using DEM in ArcGIS, Which parameters do I consider to determine DEM's pixel size and resolution?
7
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3answers
257 views

Handling mountain shadows when classifying Landsat 8

I'm trying to classify some area in northern Mongolia using Landsat 8 satellite images from 2013. Since the recordings were made in winter, the sun is very low at the acquisition time. Therefore there ...
4
votes
1answer
582 views

How to calculate and compare RMSE between two DEMs?

I'm doing a project based on using Lidar point cloud data and I have access to a DEM that cover all of Sweden. But my goal is to produce several DEMs covering a small area using different ...
1
vote
2answers
289 views

How to create DEM from Lidar point cloud data?

I'm using ArcMap and I want to create DEM(s) over an area to have different outputs depending on which settings/filters I put in. I have access to laser point cloud data as my input files. I've worked ...
1
vote
1answer
98 views

Creating Dem from cross sections

I have a question I appreciate that if someone can help me I have a DEM in arcmap and cross section of a river which flows on the Dem in Hecras. I now the cross sections are more accurate. I want to ...
4
votes
1answer
80 views

Problem of irregular contour from a DEM

I've created contour lines every 5 meters from a grid DEM with 5x5 meter of resolution. But strangely I've obtained that the contour lines are segmented and rich of lines that goes up and down, ...
11
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1answer
1k views

How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
5
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1answer
4k 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: ...
2
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1answer
128 views

How to convert different lidar data formats to raster DTM and measure its geographic position accuracy?

I'm trying to generate a DTM from lidar data and I'm new in the this field. I have different kind of files which describe the same area (different versions): *.dtm *.xyz *.xyz with variable grid ...
1
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2answers
72 views

Contour of single feature on QGIS

I'm trying to extract one single contour line at given elevation from a DEM. Taking into account that I want only one contour and not all contours with the given elevation, is there a way to do it in ...
1
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1answer
417 views

How to calculate the river slope for a lot of rivers automatically in ArcMap?

I'm working with ArcMap 10.2 and I'm pretty new in this area.. What I want to do is compute the river slope for a lot of rivers from a DTM...I know that there is a way to do it manually passing by ...
2
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0answers
32 views

infer the altitude from a DTM & finally provide it to point / evincere la altitudine da un DTM & finalmente fornirla a dei punti

I would like to complete a point vector's table with Z data. I am not able to take Z coordinate from a dtm (downloaded from ...
2
votes
2answers
371 views

automatically geo- and ortho- rectify raw Landsat data using DEM

I have a dataset of 20 Landsat scenes (MSS, TM, ETM+) for 20 years (one scene per year). Scenes are in WGS 84, EPSG 32634 coordinate system and I can easily project = geometrically correct them to ...
3
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2answers
65 views

Digital Elevation Model and Shapefile not aligned in openWind

I have a digital elevation model and a shapefile containing point features for the location of wind turbines. These two layers appear to be aligned in QGIS but when I open them in openWind, they are ...
3
votes
1answer
279 views

How can I create an DEM from Point-Data

my boss gave me a small 3D-point-shape-file and asked me to make an DEM from it, wich I should put together with an older DEM of the same site, wich was made with Surfer. I created a raster-layer from ...
2
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0answers
157 views

Command line tools to generate elevation profile from DEM + GPX/GeoJSON

I'm looking to generate elevation profiles from a number of GPX traces (which I also have GeoJSON conversions of). I have 20m resolution DEMs of the area, in GeoTIFF format. Ultimately I want to ...
4
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1answer
158 views

Highest resolution Digital Elevation Model for the UK?

I need the most precise and highest resolution free digital elevation model for the UK. Would OS terrain 50 or ASTER GDEM be more suitable for view shed analysis?
2
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2answers
188 views

How to Clip a DEM and retain DEM format?

I have a DEM file that I downloaded from the internet. I am trying to clip it to reduce the file size. So far I have tried two different methods, but neither of them produces a clipped file in DEM ...
2
votes
2answers
187 views

QGIS, interpolate along an irregular shape or line to create a DEM

Before anyone marks this as a duplicate, hear me out. This question: Interpolation: irregular shape, merging DEM's asks my question but not for QGIS. Furthermore, the answer is vague and not ...
4
votes
1answer
189 views

Creating a point corresponding to the maximum elevation of a DEM [duplicate]

I am wondering how can I create a point corresponding to the maximum elevation value of a DEM. I mean, from the DEM I can easily get the maximum elevation. For the sake of a viewshed analysis, I would ...
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0answers
55 views

Inverting color ramp in legend

I have inverted the color ramp to display land surface elevation, now when I add a legend in print composer it shows the lowest value at the top and the highest at the bottom. See below: It is more ...
2
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0answers
32 views

Drawing boundary through DEM of glacier valley using ArcGIS for Desktop?

I want to calculate/draw the boundary extent in Glacier valley with the help of DEM. Can you please guide me which is the best tools in ArcGIS and steps to calculate.
4
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0answers
82 views

Intersection of a vector linestring and underlying DEM

Following is an screen-shot where ASTER DEM raster layer has been overlaid by a road linestring vector layer. I want to extract those DEM pixels which are lying exactly beneath the linestrings. I want ...
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0answers
26 views

Buffering/extrusion of a dem surface

I have a surface representing a DEM and i would like to add it some thickness. If i simply duplicate the surface and translate it down by my thickness, i get non uniform thickness, ie thinner where ...
1
vote
1answer
82 views

Reclassification of raster surface using ArcGIS for Desktop?

I have a raster surface with values ranging from 0 -100. I want to create a categorical classification (percentage categories of 5%, e.g. 0-5%, 6-10%...) and reclassify my surface into these ...
3
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0answers
35 views

3D distance and topography

I have a set of points and want to find out the nearest distance to a water body (poly lines) taking into account the terrain and get a surface distance calculation. I understand that the way is to ...
2
votes
1answer
50 views

QGIS vector layers do not match DEM?

I have a DEM (saved as a .tif) and, using QGIS, I want to clip the DEM using a vector mask. The function will not work. Am I missing critical step?
6
votes
2answers
147 views

Reducing elevation from DEM using ArcGIS for Desktop?

I am so curious how would I strip off elevation from the DEM. I don't know how I would explain it further but I have attached an image to clarify this. I wanted to eliminate the area shaded with ...
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0answers
18 views

Where is it possible to download a DEM for the Romanian east carpathians? [duplicate]

I'm quite new to GIS and have only done a few small tasks for Projects at University and the required data has always been provided. I am now struggling to find the specific DEM I need. Also other ...
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0answers
286 views

How to convert shapefiles into ascii grid .asc in QGIS?

I downloaded multiple zips that cover a small island from the Rhode Island Geographic Information System webpage, specifically the geographic files that make up Block Island. Here's the source: ...
2
votes
1answer
209 views

shapefile to gmt format

I have an ESRI shapefile of the contours of my study area, and I want to convert it into a format that is acceptable by GMT, so I can make an elevation map of my study area. Is that even possible? ...
-3
votes
1answer
1k views

How to extract drainage line network from GRASS GIS and QGIS [closed]

Giving DEM as input is there any way to get drainage network? I am newbie to GRASS and QGIS ,provide any working examples in GRASS GIS and QGIS with procedure.
1
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1answer
48 views

DEM error when trying to do topographic correction in GRASS

I'm new to GRASS gis and I'm trying to do a topographic correction (i.topo.corr) of 9 ASTER bands using SRTM dem. I keep getting this error message: ERROR: Illumination model is of CELL type Is ...
1
vote
1answer
229 views

Stretched raster symbology not working in ArcGIS for Desktop?

I have some DEM rasters (from the same data source so I think they're uniform in all file specifications) that I'm symbolizing using the same stretched color ramp. I set the stretch type to min-max, ...
2
votes
2answers
169 views

Is there any way to 'clean' up ASTER v2 DEM data?

I downloaded all the tiles I needed, then plotted them to find that they don't all seem to have the same quality. Basically, you can see all the edges of a lot of the tiles. Is there any way to clean ...
4
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0answers
59 views

How to calculate an Illumination raster for fire ignition danger analysis?

I am doing a fire ignition danger analysis using this equation that I found in Millington (2012) http://www.jmecology.com/wp-content/uploads/2014/03/33-42-MILLINGTON.pdf IR = 4H + 3V + 2I – E Where: ...
4
votes
2answers
1k views

How to create contour lines from point data using QGIS?

I'm using QGIS 2.4.0 and I have a shapefile of points with elevation data and X and Y coordinates. I'm using windows 7 OS. The idea is to create a contour line SHP using my point data. My question ...
3
votes
1answer
589 views

How to create a catchment from a point using a DTM raster in QGIS?

I need to find a better way to delineate a catchment from a given point on a watercourse using a DTM - currently I am either using FEH, or if the catchment is too small using contours to draw ...