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

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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 ...
2
votes
1answer
94 views

Combine digital elevation model (DEM) with point layer (QGIS)

I have two layers: The first one is a digital elevation model (DEM) as GeoTiff. The second is a point vector layer (start and end of street segments). What I want to do: Add elevation information ...
0
votes
0answers
25 views

Minus elevation on DEM?

SRTM 30 m resolution data showing -23 elevation and SRTM 90 m resolution data showing -13 elevation at srikakulam dist East coastal side of India where as on google earth it is showing from 2 to 30m ...
55
votes
7answers
78k 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: DEM: Digital Elevation Model DSM: Digital Surface Model DTM: Digital ...
5
votes
2answers
231 views

Sun azimuth on shaded relief LiDAR maps

I have a LiDAR map and want to change the view so that the ground shadow is manipulated (looking for archaeological anomalies). I think it is the sun angle that I need to alter but I don't know how. ...
5
votes
1answer
275 views

How can I get the profile graph on ArcMap to display specific points?

I currently have 2 layers: 1) DEM of existing terrain 2) Polygon in vector format of future water retention basin I need to draw cross sections across this basin for eventual cut and fill calcs. I ...
3
votes
0answers
37 views

Blend overlapping DEMs using Open Source / Python

I'd like to blend edges of overlapping DEMs such that the join is a smooth transition (for use with InSAR). Apparently the best interpolation kernel for this, according to the literature, is thin ...
5
votes
2answers
4k views

Viewsheds and Observer Points in ArcGIS Spatial analyst

I am trying to understand the viewshed and observer points tool in spatial analyst. I want to show which areas of land can see a wind turbine, or put another way, from where can the wind turbine be ...
9
votes
2answers
241 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 ...
1
vote
1answer
146 views

DEM Processing in ArcMap

I have a question regarding DEM. I have downloaded SRTM DEM 30 m and I did a mosaic for the data using Mosaic tools in Arcmap to a Mosaic to a new raster. However, I got a DEM raster with values of ...
4
votes
1answer
187 views

Converting LAS 1.4 to 1.2

LIDAR files were released for major part of Slovenia few months back in zlas format. Decompressed LAS format is 1.4 version. I have tried many options how to generate DEMs and had some success in ...
1
vote
2answers
145 views

Using DTM slope map to find shortest route between two locations using QGIS?

I've got two locations, A and B, and a DTM covering the region between A and B. Say I want to drive from A to B. I want the shortest route possible, but avoiding regions with slopes higher than, let's ...
1
vote
2answers
131 views

Selecting Specific Elevation Areas Contiguous to the Coastline for Coastal Flood Mapping

This is less a problem than an inquiry into a better way of doing something. I am curious how people might go about selecting, say, all areas less than or equal to 10 feet (from a DEM) that are ...
9
votes
5answers
2k 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.
3
votes
2answers
56 views

How do I generate grid square polygons from a 5m DTM file?

For my dissertation I have collected point features as coordinates and want to relate their distribution around a lake to elevation to see if there is any pattern/relationship between them. I have ...
0
votes
1answer
75 views

How to create a series of cross sections in arcgis 10.2?

My ouput should be a series of cross-sections (10 meters apart) along a center line of a river. The input data is a raster data set with elevation values. Can I also automatically generate the lines ...
5
votes
1answer
6k views

Labeling contour lines in ArcMap [duplicate]

Can anybody give me advice on how to label contours as shown in Figure 2 below? I would like to be able to put the label "on" the line, which is easy enough. But I'd also like for the contour line to ...
3
votes
1answer
60 views

In ArcGIS 10.x, how do I select features of a point shapefile whose z values are above or below the elevations in a DEM?

I have a multi-point shapefile representing earthquake hypocenters (containing depth values) and I have a DEM raster representing an underground surface (the top of the PreCambrian basement). I want ...
1
vote
1answer
33 views

How to match river direction with DTM?

I have rivers that some times they do not match their real direction based on the DTM, and they need to be flipped. Is there any way to automatically match river direction based on the DTM in ArcGIS ...
3
votes
2answers
399 views

Filling voids in ASTER stereo-images for DEM generation using ArcGIS Desktop?

I'm trying to use a stereo-pair of ASTER images to generate a DEM (in ERDAS Imagine). However, the mountains are rather cloudy and the images can't be used as they are. But the relevant parts (valley ...
2
votes
0answers
42 views

identify and calculate area of valleys

I have a shape file (points) that contains the coordinates of a number of cities in a mountainous area (valleys separated by mountain ridges), and a DEM of the area. I would like to calculate the ...
1
vote
1answer
81 views

Finding area of DEM raster clip?

I have a DEM layer in ArcMap 10.2 which I then clipped to fit a large shapefile. I'm trying to find the area of the new DEM shape using the Image Analysis tools, specifically the Mensuration tools. I ...
1
vote
1answer
255 views

SRTM vs Google Earth Pro elevation data

I am working on elevation data for an area in Sudan. Between Google Earth Pro and SRTM elevation data, which one is more reliable?
2
votes
0answers
45 views

3D model to DEM, maintain volume?

Bit of a challenge here which I've been grappling with for some time. I'll explain my full work flow so you can reproduce if needed. I'm creating virtual landscapes in Google SketchUp which I ...
1
vote
0answers
39 views

Calculating aspect in flat areas in ASTER DEM with ArcGIS for Desktop?

I have an analyzed aspect surface from ASTER DEM 30m resolution in ArcGIS 10.2. But it shows many aspects in flat area.Normaly it must calculate this are as flat (-1). How can I resolve this problem? ...
4
votes
3answers
214 views

Adding two raster datasets that overlap while maintaining extent of larger raster dataset?

I am using ArcMAP 10.0 How do I add two raster datasets that overlap while maintaining the extent of the larger raster dataset. I have thought of adding zero values to the smaller raster to then be ...
0
votes
0answers
80 views

Making DEM and Landsat Image Coincide in ArcMap?

I have a DEM with these properties: Spatial Reference: GCS_WGS_1984 Angular Unit: Degree (0.0174532925199433) Datum: D_WGS_1984 Raster Information: Columns and Rows: 3051, 2426 Cell size: ...
0
votes
0answers
73 views

Creating a DTM from Contours, via the command line or Python

I am looking to create a gridded DTM/DEM (Digital Terrain/Elevation Model) or TIN (Triangulated Irregular Network) from a set of contours. There are a number of similar questions on both this site ...
0
votes
1answer
23 views

Strange Vertical Mapper issue

While using the Mapinfo 7.0+ Vertical Mapper 3.0 on a Windows 8.1, I am facing the following issue: After adding a DTM (in .grd format), which is displayed perfectly, I am trying to use the Grid Info ...
15
votes
2answers
2k views

Generating contours from DEM using GDAL?

We have just received a large set of DEMs at work and I would like to generate contours from them. The DEMs have a resolution of 1m and a size of 1kmx1km. Output from gdalinfo: Driver: ...
0
votes
0answers
25 views

Apply mask on ERDAS LPS

I am currently working on my final year dissertation and most of it is done on LPS. I am using Cartosat-1 and ALOS PRISM imagery to create DTMs for an area that is located on a peninsula. The problem ...
0
votes
0answers
61 views

erdas LPS : Load Z values from a DEM?

I'm working on a photogrametric project with erdas LPS version 2013. I succeed in taking several ground control points (x and y values). However, i can't extract and load Z values from my raster DEM ...
0
votes
0answers
24 views

Orfeo Toolbox DEM download error

I have been trying to use the following part of the Orfeo Toolbox to download DEM data from usgs. I have been passing it a geotiff image as the reference and am receiving the following error: 2015 ...
2
votes
1answer
1k views

How to extract DEM files from google Earth/Map for surfer?

I will need to do a 3D representation of a terrain and I heard surfer is ideal, but then I do not have a DEM file of the region, I know Google Earth and Map could help, but I do not know how? If there ...
0
votes
0answers
112 views

How to make DEM raster in Google Sketchup?

I would like to make DEM in google sketchup, later add 3D buildings and finally convert this file to raster. Afterwards, I want to import this raster to GRASS GIS to make solar maps. It is possible to ...
1
vote
0answers
59 views

Las tools vs Geocue for LAS1.3 processing [closed]

I am a user of terra solid products. I have las1.3 data set which i need to perform whole processing in 1.3 version. (I need to supply WDP informtaion and classified las dataset as well. So I afraid, ...
3
votes
4answers
196 views

How can Identify highs on a DEM?

I have a DEM and I want to find each hill and create a polygon for its area, effectively the out closed contour that encloses the hill. I can do this visually but I'm about to work on a larger area so ...
2
votes
2answers
805 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 ...
2
votes
0answers
654 views

GDAL tiling DTED (dt2) dataset as gdal2tiles for 3D Maps

i am searching some webgl technologies to create 3d map with digital elevation data. for web tech. i have found ReadyMap SDK to create 3d map from TMS... in ReadyMap for elevation data it uses sth ...
0
votes
0answers
12 views

Where to find free DSM data of Switzerland (Ticino)? [duplicate]

I am working on a sonification project. My aim is to sonify data coming from a delimited area in Switzerland. I also would like to print out a 3d map of that region based on that data. Problem is : ...
1
vote
0answers
66 views

How to extract area information from a raster based on a DEM or contour lines

I have a raster representing the distribution of a specific land cover type - the raster values are 1 for where the land cover type is present and 0 where it isn't. I also have a DEM with 5m ...
5
votes
1answer
147 views

How to run a tool from Whitebox GAT in ArcGIS?

I have a series of tools that I need to run in ArcGIS to hydrologically condition my DEM, but the first step in this process is running the Breach Depressions tool from Whitebox GAT (I have found that ...
19
votes
3answers
1k views

How to create transparent hillshade?

I get elegant transparent hillshades via a combination gdal and convert. Compare to grey-based hillshade commonly used, such transparent hillshades are very cool because they can be placed between the ...
7
votes
2answers
2k views

Splitting raster into smaller chunks using GDAL?

I have a raster (USGS DEM actually) and I need to split it up into smaller chunks like the image below shows. That was accomplished in ArcGIS 10.0 using the Split Raster tool. I would like a FOSS ...
0
votes
1answer
167 views

What do negative DEM values mean?

My DEM elevation values varies from -255 to 81. What does the negative values imply? I have downloaded the dem from BHUVAN. About 90 % of values fall in negative category. How can I convert these ...
4
votes
2answers
142 views

How to export a polygon based on elevations using a DTM or a DEM

I have a LiDAR generated DTM and a DEM (accurate to 10x10 feet). I am trying to export a polygon within a boundary which includes all elevations below a specific number. Seems like this should be ...
2
votes
0answers
39 views

Mosaic DEM has large pixel when displayed in ArcMap?

I created a mosaic dataset in ArcMap 10.2 from tiles of ASTER DEM's at 30m resolution. I am attaching the image of what my export looks like. You can see that there are extremely large, alternating ...
2
votes
1answer
2k views

Converting mosaic dataset to TIN gives error? [closed]

I merged several DEMs together in on single DEM with mosaic dataset. Now I wanted to convert this mosaic dataset in Vector with TIN. But when I use the tool (3D Analyst Tool) Raster to TIN comes an ...
2
votes
1answer
58 views

How do I find out the sea levels?

I have following elevation data of a region (the higher the altitude, the brigher the points): How can I find out, which areas are filled by water, and which not? Can I assume that if the ...