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

learn more… | top users | synonyms (1)

4
votes
1answer
111 views

Obtaining sink morphometry from local minima points

I am working on LiDAR data from GIS and R and I want to extract landforms from the DEM. I have found a method to obtain local minima points of my LiDAR data. However, I would like to obtain the ...
3
votes
0answers
95 views

Add a dam to DEM in ArcMap

I followed the instructions how to build a dam by whuber (How to build an artificial 'dam' across a river?) "draw a line segment" "compute the Euclidean distance to this line segment" ...
10
votes
2answers
3k views

How to build an artificial 'dam' across a river?

I have a DEM. Created all files related to watershed including accumulation, direction, streams etc... I'm stuck creating a dam. I request you to please let me know how to build an artificial 'dam' ...
0
votes
0answers
21 views

Error : LayerRasterRead failed : Imagine Photogrammetry

I'm using Imagine Photogrammetry ( ERDAS ) and I would like to generate a Data Elevation Model DEM based on PLEIADES imagery. When I execute erdas , it seems like he is computing the DEM but after ...
4
votes
2answers
825 views

Retrieving average building height in urban areas

I am looking for a way to collect data on the height profile of some cities over time. I don't need to produce a detailed 3D reconstruction of cities, nor do I need to detect and measure individual ...
3
votes
1answer
38 views

Help with Rastercalculator - Filter areas with a certain height difference

I'm struggeling a little bit with the rastercalculator tool of QGIS. At the moment I am working with a DSM and a DTM. My aim is to filter all wind turbines out of the DSM and replace it with the ...
2
votes
1answer
108 views

How to find a point with highest elevation in area using ArcObjects

Is there a way to find a point with highest elevation in specified area by using ArcObjects? Let's say that I have a raster with DEM and I would like to establish some areas of interest in this ...
1
vote
1answer
53 views

Converting DTM data to STL?

I'm new here and was wondering if anyone could help? I'm looking to make some 3D maps using DTM data but need to convert it into .STL format for my MasterCAM to read so that I can generate the CAD ...
11
votes
4answers
8k views

Burning stream network into DEM layer using ArcGIS Desktop?

I am working on a DEM that in an area where there is little relief. I would like to 'burn' the river network into the DEM so I can calculate flow accumulation and flow length accurately. I am ...
1
vote
1answer
86 views

Making DEM from contours without elevation data?

I got a shapefile with contours, but no elevation data is present. We can assume as known info, that the contours mark elevations at known steps (say, 20 m). Is it still possible to restore the ...
1
vote
2answers
143 views

Determining Min and Max elevation in Python using GDAL? [closed]

I have a DEM file and shape file of specific area ,and i want to Create a module in Python that writes name of each area which is shows in the picture, with the greatest differences in altitude on ...
1
vote
0answers
51 views

Why does the flow direction tool in ArcGIS desktop give wrong output (unique values from 1-255)?

I ran the flow direction in ArcGIS, and received unique values ranging from 1-255. I know that these values are wrong, and should be along the lines of 1, 2, 4, 8, 16, etc multiples. The DEM is ...
0
votes
0answers
30 views

Aster DEM damaged file (N30 E041)

I tried to merge several raster data sets ( from Aster GDEM), but one file is possibly damaged and I get a hole in my raster, see here ...
1
vote
2answers
121 views

“ERROR 010214: Unable to read STA of…” while running Arc Hydro Geoprocessing Tools

Today I tried running the Combined Terrain with Unknown Sink and Stream Locations Tool from the Arc Hydro Toolset (version 10.3.0.58, ArcMap 10.3). As input I used a DTM with values between -10 and 19 ...
7
votes
3answers
271 views

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

I´m trying to extract DEM and DTM from a LIDAR file. Currently, I rasterize the image but don´t know which algorithm I need to apply to obtain the DEM and DTM information in different models to be ...
2
votes
0answers
17 views

Applying colour ramp to DSM in ArcGIS using real elevation values as colour cut-offs?

I have a topo-bathymetric lidar DEM that I need to construct a CSR for in ArcGIS 10.3. I know how to make colour ramps and personalize them, but I'm wondering if it's possible to make a ramp based on ...
3
votes
2answers
3k views

Using Phantom 3 Pro to capture aerial imagery for small site plans and derive DEM?

I am curious if this consumer UAV can be used to capture imagery for further processing to stitch seamless imagery and to use as input into stereo/photogrametry software to create reasonably accurate ...
0
votes
1answer
27 views

DEM data to Excel using ArcMap?

I have downloaded a DEM from digmap and have opened it in ArcMap. I now want to transfer elevations from each gridsquare into excel to be used in a water routing model. Do you have any ideas how ...
0
votes
2answers
126 views

How to create a reservoir for a dam site?

I have created the watershed for a proposed dam site point using SRTM 90m DEM. Now my task is to create a reservoir or pondage where water would be collected from the watershed. Above a watershed can ...
0
votes
3answers
384 views

Why is my DEM in ArcScene flat, not 3D?

I am working with Digital Elevation Models in format TIFF 2km * 2km. As far as I know DEMs should have a 3d function but in my case the DEMs are flat. They only look 3d because of the hill shading. ...
1
vote
1answer
47 views

Regarding Atmospheric correction and Elevation DEM Projection system

I am trying to conduct atmospheric adjustment of Landsat 8 image bands using 6s algorithm (i. atcorr grass gis tool). It seems, in the input section, an elevation raster map should be provided. In my ...
1
vote
1answer
58 views

Creating contours from DEM for multiple files using ArcMap ModelBuilder?

How can i create an ArcMap model in ModelBuilder to iterate through a folder and applying contouring tool on all tif DEM files on that folder.
0
votes
1answer
37 views

gdaldem hillshade using command to calculate hillshade of whole folder [closed]

I need to calculate hillshade of folder using gdaldem hillshade which has 60 files in it. How can i do it using command prompt window.
2
votes
0answers
51 views

Fixing undesirable lines between tiles from SRTM contour line extraction?

I'm trying to make a South American topography map based on SRTM data on QGIS. The problem is a visual one. If the topography contours are extracted from individual SRTM tiles, it results a little ...
4
votes
3answers
139 views

Irregular XYZ point data to raster (TIF) - LASTools alternative?

I am trying to convert my irregular spaced point data (xyz) to a DEM and then, to a raster (geotiff). Because of the irregular spacing I need a triangulation first, right (so, no spaces are in the ...
6
votes
2answers
419 views

Simplified flood “model” / estimation from elevation data

The goal is to present an estimation of potential flooded area. But still keeping it simple. I know this will not be accurate. The question is: will it be good enough for at gestimate / rough ...
2
votes
1answer
830 views

Combining DEM raster with vector data in ArcScene?

Ive have a raster layer of earthquake data that includes depth. I also have a DEM file. The problem is that I need to plot earthquake depth relative to the DEM file rather than sealevel in order to ...
2
votes
1answer
59 views

Looking for DTM for Morocco

I am looking for a DTM for the city of Agadir in Morocco. Could anyone help me to find it?
1
vote
0answers
47 views

Calculating flow distance of pixel from outlet using R?

I have created these raster files for a river basin: DEM Flow Direction Flow Accumulation Also, I have another raster with values of rainfall. All the 4 rasters have same spatial extent, ...
0
votes
0answers
25 views

DEM Mosaic Dataset Processing - Output Surface and Hillshade raster to same extent as input raster tiles

I have a lot of DEM rasters, tiled adjacent to each other. I would like to make a surface and a hillshade raster to the same extent as each DEM tile. Current issue: processing on a tile-by-tile basis ...
4
votes
1answer
74 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: ...
1
vote
1answer
82 views

General guidelines for topographic contour to DEM conversion?

It seems that many different DEM resolutions (10m, 30m, 100m) could be created from a contour map (with, for instance 50m elevation changes marked), but of course some of the resulting DEMs will be ...
1
vote
0answers
70 views

How to orthorectify an image from a hilly region without sensor parameters but with DEM and some GCPs in ERDAS or ArcGIS?

I have a raw raster image from a sensor, but do not have the possibility to obtain the sensor parameters. However, I do have a (older) reference ortho image and a DEM with good accuracy. Both are ...
4
votes
2answers
2k views

Drawing irregularly shaped boundary polygon around set of LAS points using ArcMap?

I am working with a set of LAS data which is irregularly shaped, picture a starfish as the point coverage, surrounding the starfish may be water on one side, may be more land elsewhere but no points ...
0
votes
0answers
22 views

building artificial dam in a canyon [duplicate]

I want to calculate the water volume dammed by a dam in a canyon. I managed to calculate the water volume but I actually need a dam in a certain place of the gorge so I can pursuit my calculations. I ...
2
votes
0answers
57 views

Acquiring Digital Elevation Models for Argentina from commercial providers

I'm interested in obtaining Digital Elevation Models for areas in the 20,000 acre range, as I use them to create contour maps for agriculture. The USGS Earth Explorer has a wonderful free DEM ...
1
vote
1answer
45 views

increase resolution of generated hillshade on QGIS

I want to export a hillshade (geotiff) created from a DEM as an image for printing. But the resolution of the hillshade is way too low (900 colums, 1450 lines). Any way to upscale it? (I tried ...
2
votes
2answers
82 views

Finding DEM/HIllshade sources California

Creating watershed maps for schools. I want to color ramp the elevation to show low and high points. What kind of files do I need and where to find them?
6
votes
3answers
2k views

Finding elevation differences between adjacent pixels in ArcGIS Desktop?

Is there a way to determine what the difference in elevation is between two adjacent pixels? I am using an SRTM DEM to map faults. I am using the vertical error (>16m) as a criterion for the ...
2
votes
1answer
34 views

applying a gradient to terrain curves in QGIS: problem

I'm trying to apply a gradient to terrain curves generated from a geotiff. I then choose a graduated style with a gradient color palette. everything seemed fine until I noticed that from a certain ...
7
votes
3answers
1k views

How to extract mountain peak points from a given digital elevation model?

For past couple of days, i m trying to determine how many mountain peaks are visible (line of sight) from a given location using POSTGIS. The data i have is DEM for Swiss and address locations from ...
2
votes
1answer
51 views

Clipping DEM / DTED data selecting by extent

similar to a few queries but really struggling to clip a DEM file from say USGS. Going to Raster > Extraction > Clipper and then "select the extent by drag on canvas", does not work. The process ...
1
vote
0answers
47 views

QGIS - .vrt DEM layer only partially goes to hillshade

I am using QGIS 2.12 on Macbook Pro running on Mac OS X Yosemite 10.10.5. I have six adjacent DEMs of the 7.5-minute quadrangle size (National Elevation Data or NED, I think). I loaded them into a ...
1
vote
1answer
84 views

Elevation adjustment DSM using Ground control points

is there any possibility to improve the vertical accuracy of a given satelite DEM/DSM by using exact measured ground control points? And if so, which software is recommended?
4
votes
1answer
2k views

What is the highest obtainable resolution of FREE elevation data in the UK?

I am seeking closure with this question guys. I am aware of various sources of free elevation data ~30+ m, and I have been searching for higher resolution FREE data for a while now. This already ...
7
votes
1answer
7k views

Where to acquire elevation data for UK?

I'm looking for digital elevation data for UK. Does anybody know if there is a good service providing data for free that are of better accuracy than ASTER-DEM that is around 30m and if not what is the ...
2
votes
0answers
37 views

Wanted: A rather large DEM

I am looking for a rather large DEM --- on the trillion cell scale --- to run some tests on. So far, I have found: 200 billion cells: The SRTM Global Dataset 30m DEM 120 billion cells: The National ...
1
vote
0answers
56 views

What is the usefulness of the angle and direction of the sun parameters in hillshade? [closed]

These parameters refer to the angle as of elevation and direction of the sun hypothetically to the hillshade but why does that must have any importance?
32
votes
7answers
22k views

Choosing colour-ramp to use for elevation?

This is maybe rather subjective as it concerns style, but I would like to have a few decent colour ramps for my DEM when it is layed over my hill-shading. I have created the Swiss hillshade model as ...
0
votes
0answers
53 views

Generating DEM from point cloud and DEM differencing?

I have two point clouds obtained via structure from motion (ground photos of sand-dunes + Visual SfM/Agisoft Photoscan). If I wanted to generate a DEM from these point clouds and difference them to ...