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

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41
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8answers
53k views

What is the difference between DEM, DSM and DTM?

I am listing some of the acronyms used in our work and had to stop to think about whether to list these together or separately. In some circles they are synonymous, in others they have distinct ...
2
votes
1answer
288 views

How to remove strange gdaldem hillshade artifacts?

I've downloaded 9 chunks of 1 arc-second NED in IMG format from the National Map. I'm trying to create a hillshade from them. I'm using: GDAL 1.10.0, released 2013/04/24 First, I combine them and ...
4
votes
6answers
3k views

shadow simulation from buildings [duplicate]

is it possible to use hillshade function in ArcMap to calculate shadow areas of buildings or simulate shadows of buildings, using DSM of the buildings and the sun angle and azimuth?
9
votes
3answers
256 views

How to create composite hillshade?

The concept of composite hillshade is to combine multiple hillshades with different sunlight orientation to avoid blind spot. It requires to merge 3 hillshades images with 315⁰ (NW sunlight, default ...
0
votes
0answers
28 views

change from NAD 1983 to some PCS?

I want to ask how to change the coordinate system from NAD 1983 to some Projected coordinate system. I tried to change this DEM file to WGS 1984 (all of them) but when I did that my scale becomes 1:4. ...
0
votes
2answers
67 views

DEM with bathymetric contour lines in GRASS

I am trying to create a DEM from a bathymetric contour lines. Contours are in vector format and the elevation value is negative. To create the surface I have converted the contours in raster (v.to ...
1
vote
1answer
24 views

Where to download Mars DEMs and landcover?

I'm looking on the websites of the Mars Global Surveyor and the NASA sites, but all of the data is in jpeg or img form. Does anyone know where to find useful raster data sets for elevation and land ...
0
votes
1answer
224 views

DXF (points and lines) in QGIS - Doesnt import z coordinates

Trying to get to grips with QGIS, coming from a Mapinfo and Civil3D background. I have a DXF file with points (X,Y,Z) and lines. I want to open this in QGIS and use the interpolate plugin to create ...
1
vote
1answer
76 views

Hillshade with too big pixels

I digitized some maps with isolines every 4m. I created a DEM and the Hillshade. But the hillshade has big pixels. I use ArcGIS 10.3. Is there something to be look out for that I might have done ...
2
votes
1answer
283 views

Extract elevation data from Landsat / MODIS imagery?

Just curious, have anyone tried to extract elevation data from LANDSAT or MODIS imagery? So far, I came across one journal by Toutin who did so using adjacent LANDSAT 7 imageries. Results seem pretty ...
2
votes
1answer
124 views

Choosing the right parameters to interpolate a DEM from contours

This is my first question on the forums, so be gentle :) I have a 5 meter interval contour lines feature class which I would like to interpolate to a DEM. I am well aware of at least 2 tools ("tin ...
3
votes
1answer
611 views

“Topo to Raster” tool for QGIS?

is there any analogue of the ArcGIS "topo to raster" tool in QGIS? I need to creates surfaces from shp for some cases from points and for some from lines and this instrument is very convenient.
9
votes
3answers
2k views

Create DEM from stereo pairs?

Does ArcGIS Desktop or any of its native extensions allow me to create DEMs from stereo pairs (acquired by satellite, GeoEye 1)? If the answer is a clear no, brownie points will go to an answer that ...
1
vote
1answer
137 views

Can we create topographical map of private land using GPS elevation data?

Is there a way to create a relatively precise topographical map of a private land using GPS elevation data? As the land is a little bit over 100,000 square meters, the available regional topographical ...
1
vote
1answer
21 views

Does Scimap work with QGIS?

Does anybody know if Scimap ( http://www.scimap.org.uk ) works with QGIS? I know it is supposed to operate with ArcGIS and SAGA but as I am very much a beginner with QGIS I would like to know if its ...
2
votes
1answer
26 views

How to average gdal_hillshades?

For some unknow reason, my average of 3 hillshades is very dark : gdaldem hillshade input.tif hillshades_C.tmp.tif -s 111120 -z 5 -az 315 -alt 60 -compute_edges gdaldem hillshade input.tif ...
3
votes
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 ...
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 ...
1
vote
0answers
34 views

Modifying DEM elevation data in QGIS using a polygon

I've tried searching through the existing questions but am struggling to find a succinct answer to what I am trying to achieve. For background, I am running a flood model in TUFLOW to help support a ...
4
votes
1answer
85 views

How to use SRTM Global DEM for Aspect calculation?

I need to derive a raster representing aspect for North America (from STRM data, originally in geographic lat/long). In most projections, true north is only map north along eg the central meridian so ...
0
votes
0answers
79 views

Filtering noise out from bare-earth DEM with terrace fields?

I have a 1m bare-earth DEM, derived from LiDAR data, representing a terraced landscape. For the sake of any subsequent use of the DEM (e.g., least-cost path, cost surface analysis, and the like) I am ...
2
votes
1answer
72 views

Creating DTM for two surfaces with point data and calculating volume between them using ArcGIS Desktop?

I have point data for a ground surface level which is captured in a grid of 35m spacings. I also have point data for the new surface level after soil has been removed which is captured at random ...
0
votes
0answers
41 views

qgis2threejs - rendered surface edges “bleed”

I am using qgis2threejs on some raster datasets representing different potentiometric surfaces of aquifers. The rendered 3D images from qgis2threejs have the edges of the surfaces "bleeding" down to ...
2
votes
1answer
38 views

merge two DEMs of different resolutions? [duplicate]

I have two DEMs, the first one is in 30 meters of résolution and the second: 5 meters, and will like if there is a possibility of merging them to extend the area where I do my research?
1
vote
0answers
50 views

Convert contour lines to DEM in ArcGIS [closed]

I've been trying without success to convert contour lines to DEM (Converting to spot heights is also a possible solution but I have not found a way for that either) using ArcGIS 10.2 (Advanced ...
4
votes
5answers
1k views

Elevation correction ASTER GDEM2 (+10m)

My ASTER GDEM2 has a average elevation error of -10m for my area. (I testet it using 90 defferential GPS reference points and compared it with old Topo25, SRTM, and GoogleMaps). I would like to ...
0
votes
0answers
52 views

How to mosaic to new raster for multiple DEM tiles?

I took some DEM files and turned them into raster .tif files, i then tried to Mosaic them together using the mosaic to new raster tool and i keep getting two problems consistently, there seems to ...
0
votes
1answer
133 views

Creating Digital Terrain Model from Digital Elevation Model using ArcGIS for Desktop? [closed]

I have a DEM and I want to create a DTM from that DEM. Is it possible to do this in ArcGIS?
0
votes
1answer
73 views

How to remove negative values from DEM using ArcGIS for Desktop?

i'm using (ArcGIS 10.1) and i want to remove a negative values from DTM in order to keep just a ground topographic surface.
2
votes
2answers
174 views

Classifying DEM according to elevation in R?

r<-raster("DEM.tif") How to do the classification based on every ten meters for example and have different colors too?
2
votes
1answer
42 views

Automatically adding Z-values from a DEM to an already created polygon

We have excavated a very large 5.000 year old fish fence, which was documented by photogrammetry, and is now being digitized. I started digitizing the orthophoto in QGIS and everything is cool. Now ...
0
votes
1answer
40 views

Intermediate files disappear in ArcGIS 10.1

I am working with ArcGIS 10.1 creating some slope and aspect files. I do this: DEM_park = ExtractByMask(mosaic_name, park_area) and it creates the DEM_park file in a default gdb with a default ...
0
votes
3answers
368 views

Import DEM into PostGIS for QGIS

I'm a complete GIS newbie so sorry if I'm using the wrong terminology in searching for a solution to this... I'm trying to import a DEM into PostGIS and display it in QGIS. The data is from the EU-DEM ...
1
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0answers
35 views

How to fit Google Earth satellite image to UK OS 50 DEM

I have extracted a DEM tile from the UK Ordnance Survey's free OS Terrain 50 dataset The tile contains spot heights for a grid comprising 51 nodes (West to East) by 51 nodes (North to South) with ...
3
votes
1answer
91 views

DEM Stream Burning

I would like to ask you guys how would i burn streams in DEM the following images will help understand what I would like to do. this is my DEM and the blue lines are my rivers. However, when I ...
1
vote
2answers
40 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 ...
1
vote
1answer
39 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 ...
1
vote
1answer
20 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?
1
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2answers
125 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 ...
8
votes
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 ...
1
vote
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
votes
2answers
284 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
votes
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
votes
1answer
196 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 ...
0
votes
0answers
14 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 ...
2
votes
1answer
67 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 ...
0
votes
1answer
49 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 ...
3
votes
0answers
74 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
votes
1answer
202 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 ...
1
vote
1answer
45 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 ...