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

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2
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1answer
145 views

Finding Two locations with conditional search on DEM?

I want to find two locations H difference in elevation between two locations on a DEM. Ex: point A and B are my output after search on DEM. conditions are: buffer R distance around point A and ...
19
votes
4answers
16k views

Creating DEM from contours in QGIS?

Is it possible to make a DEM from contours in QGIS? I have a shp file (contours) and their heights, can I use QGIS for produce a DEM without using GRASS? I found this creating a dem from contours ...
1
vote
1answer
42 views

Creating DEM from topography map in QGIS [duplicate]

For my geology diploma project I need to create DEM from topography map my professor gave me to use as a base map. The map is georeferenced. My idea was to draw lines over the izolines of the map, ...
3
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0answers
52 views

How to calculate best path between 2 points from a DEM in Qgis?

I'm analyzing the roads and paths of a region by calculating how effective the communication is in the region. First I calculated the shortest paths between the points using the actual road map. Now ...
2
votes
1answer
56 views

How to derive a hydrologically correct DEM from point shapefile using QGIS?

I used grass gis v.surf.rst function to interpolate a surface using vector points. But it is very difficult to find a optimum parameters to be used. I am still unable to develop a accurate terrain
2
votes
2answers
78 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?
0
votes
1answer
84 views

How to find the height information from LiDAR point cloud data [duplicate]

I need to find the biophysical parameters(biomass) from the LiDAR point cloud data. For that I need the height of the trees from the data. Currently I am having the general height with respect to sea ...
0
votes
0answers
33 views

Stream Burning/DEM Reconditioning

I am conducting a regional study in the Midwest. I was wondering if stream burning would be necessary for this large region. I am using a 90 meter DEM. If stream burning is necessary, what should the ...
1
vote
1answer
41 views

Extracting coordinates of a triangulation from DEM data

I'm working on the succinct representation of planar graphs and now I'm trying to obtain some datasets to test my results. I saw that Delaunay triangulations of elevation data can be a good source of ...
6
votes
3answers
127 views

Vertical datum query for coastal modeling

This may be very specific. I have a USGS derived DEM with a vertical datum of EGM96 from NASA satellite data. My Bathymetry uses a lowest astronomical tide datum. Has anybody come across this or ...
1
vote
1answer
543 views

Importing ERDAS-processed GTOP030 dem data into ArcGIS Desktop?

I have two GTOP030 DEM images. After downloading them, I have imported into ERDAS and mosaiced them. Then I have exported it to .tif file in order to open it in ARCGIS. But when I tried to open it in ...
0
votes
1answer
41 views

How do you identify cuttings / crevices from a DTM or DSM using ArcGIS?

I am trying to identify where cuttings and crevices exist by using a DTM or DSM. My ultimate aim is to find where roads and rail lines sit within a cutting i.e. the land either side of them is higher ...
1
vote
0answers
29 views

Creating tiling scheme to get multiple extents before gridding elevation data

Looking to create 1 degree by 1 degree tiles with pixel overlap to get extents before I start gridding. So basically I would like to have a shapefile of the tiling scheme with extents before having ...
3
votes
0answers
49 views

Building a DEM with both a raster and vector points [closed]

So I'm struggling here, trying to get a decent DEM for the Azores Islands because I want to include bathymetric data on it. I have a raster with elevation for the islands (land) with a 30 meter ...
0
votes
2answers
99 views

Resampling DEM using gdal in python?

Using gdal I want to resample (in this case, oversample) a DEM. The only thing that should change is the pixel spacing, so I want to interpolate in between the values that I currently have. For this I ...
1
vote
0answers
38 views

Generating continuous aspect surfaces from DEM with QGIS

I'm trying to extract aspect surfaces from different DEM sources at different resolutions in QGIS. I've had success working with SRTM-derived grids (3-arcseconds) and am trying to perform the same ...
0
votes
0answers
14 views

Volume of free space between valleys using arcgis [duplicate]

I'm having DEM and I want to estimate volume of wastes that can be dumped in valley. For that I want to estimate volume of free space between valleys. How should I estimate volume of free space in ...
2
votes
1answer
2k views

Converting 32 bit DEM to 16 bit in ArcGIS Desktop?

I have a 32 bit DEM with resolution 0.5 * 0.5 and range of elevation is 1299 to 1489. When I want to export or use copy raster tool or create fill in Arcgis, the results are elevation between ...
4
votes
0answers
58 views

OS terrain 50: .vrt from zip files

I tried to follow what was suggested in How to use OS Terrain 50 in QGIS, but I got the following problem: in spite of being generally able to generate .vrt files using gdalbuildvrt from unzipped ...
2
votes
2answers
370 views

Driver Error : DTM to Raster using GDAL_GRID

I am looking to interpolate a DTM (eventually over 4,000 DTMs) that is in a personal geodatabase format. I would like to do this in as few step as possible, eventually writing a batch script to do ...
2
votes
1answer
28 views

Creating Data Elevation Model from two sources

I have 2 Data Elevation Models ( Aster with 30 m resolution and a DEM obtained by stereo with 4 m resolution ). Unfortunatly the DEM with high resolution contains a lot of no data value and some ...
3
votes
2answers
2k views

How do I know the vertical/horizontal units of my DEM? I'm creating a slope using gdaldem

I'm using gdaldem to create a slope map. I can apply a scale. The default is 1. The notes say: Ratio of vertical units to horizontal. If horizontal unit of source DEM is degrees (e.g WGS84 ...
0
votes
1answer
59 views

Extracting channel banks from DEM and channel newtork

Currently I am working in project that require from me extracting channel banks. I have been thinking about the best method that I can use to come up with good function that extract the location of ...
4
votes
3answers
1k views

How to fill sinks in DEM with specific amount of water

I identified the sinks in my terrain based on the DEM (grid) by using the 'fill'-tool and substracting the original DEM from the filled DEM. I also identified watersheds as well as flow paths. Now i ...
3
votes
1answer
76 views

Why do multiple raster processing tools fail with this DEM?

I have a provincial sized DEM. I need to clip it to a fairly large watershed boundary. Should be easy. I've tried: Data Management Tools -> Raster -> Raster Processing -> Clip (Did I make sure ...
6
votes
2answers
532 views

best and most accurate free DEM?

I'm working in France. I thought the TanDEM-X was a free and open DEM but that does not seem to be the case. According to a few websites, the most famous free DEMs seem to be ASTER GDEM, SRTM, X-SAR ...
3
votes
1answer
61 views

How to delete obstacles (corduroy road) from DEM in ArcMap?

I have a DEM which looks like this: The narrow longish lift running from north to south is a corduroy road (hope this is the correct word for "planks which allow people to cross a mire without ...
1
vote
2answers
57 views

Finding average elevations from a Raster DEM, applying those to Vector Grid created with GME

I'm using ArcMap 10.3, and here's what I have: I have an angled vector grid created through GME's GenVecGrid tool which has been clipped to an irregular size and angled relative to the xy axes to ...
7
votes
3answers
10k views

Viewing .las format LIDAR data in QGIS?

Is there an easy path to visualizing this LIDAR data? I have QGIS, and some USGS LIDAR data in (.las) format downloaded from http://lidar.cr.usgs.gov/ . This means I have both the (.las) and ...
0
votes
1answer
48 views

Uncompressed size of ASTER DEM tile is 0 Bytes

I have downloaded ASTER DEM tiles(n=400), I have to merge/mosaic them. While doing so I got a problem with one tile which does not merge but displays correctly. I have downloaded it again but still I ...
4
votes
1answer
772 views

How to give elevation information to a polygon feature class using existing TIN file ? (geological mapping)

I'm an ArcGIS 10.1 user. My issue: I have a printed form of a map which depicts geological bodies being surface rock occurence. Additionaly, there are elevation contour lines. I digitized the map by ...
1
vote
0answers
12 views

Inserting ground control points in ASP NASA?

I am using PLEIADES stereo images and  the Nasa software : Ames Stereo Pipeline (ASP) in order to generate a Data Elevation Model (DEM). In addition to that, I have some ground control points and I ...
0
votes
1answer
37 views

Surfaces and Rasters in DWG format

I have been asked to export a DEM into DWG format, is this possible? The only thing I can think of is to create a regular grid of points and to export this. Also I have been asked to save geotiff ...
0
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0answers
3 views

Is there any publication about TIN MDE file formats like ESRI TIN or ITF?

I would like to cite in my thesis how GIS software deal with TINs both via files and in the memory during execution. Any scientific or technical publication about GIS file formats would be helpfull. ...
0
votes
0answers
8 views

Create a new DTM with shape [duplicate]

I have a DEM (bare earth elevation) and a shapefile footprint of building. I want to do a hydraulic simulation in this area. Is it possible, with a free software, to create a new DTM where, using the ...
3
votes
1answer
59 views

Standardising DEM raster for a MCE

I'm trying to complete a Multi-Criteria Evaluation for an MSc assessment and am in the process of standardising my factor maps. Unfortunately, my DEM layer (ASCII file) keeps changing from this: ...
3
votes
1answer
213 views

Choosing the right parameters to interpolate a DEM from contours

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 to raster" and "topo to raster") which can help me with ...
1
vote
1answer
57 views

In qgis2threejs html output select deselect the layers not working

I used qgis2threejs to output 3d model with a dem and another viewshed output. I want to tick untick the layers for displaying and not displaying the layer.But the select unselect option in right ...
3
votes
1answer
2k views

Determining if DEM has z values?

How do I know if the DEM contains z-values? I am looking at the DEM's layer properties and it does not mention the z values. I then add it to ArcScene and tried to find it without success. It ...
1
vote
1answer
58 views

Bathymetric-topographic DEM color relief?

I am using QGIS 2.12 on a Macbook Pro running OS X 10.10.5. I have an interesting DEM for the California coast (which I downloaded from Santa Barbara, CA 1/3 arc-second MHW DEM. I've been playing ...
1
vote
1answer
95 views

Slope analysis of DEM in QGIS?

I have very strange problem with the raster analysis. I have a DEM as a Geo tiff and I do a slope analysis in QGIS. I've done this many times and everything was ok but this time I received reversed ...
1
vote
0answers
43 views

Turning simple raster file into DEM?

I'm using QGIS LYON 2.12.1, and I want to turn a plain gray scale raster file (that I got from Google search) into a DEM. The aim is to apply the DEM (terrain models) function to the newly created ...
1
vote
0answers
28 views

How to create a numerical mask file with the elevation points of an area with QGIS

I'm using QGIS and I have to create a mask file (.txt) as an input for a hydrological model. The file should be a numerical grid map that represents the elevation points of a catchment area, like the ...
7
votes
3answers
646 views

Filtering out canopies and buildings from DSM to have a bare earth elevation

Can anyone suggest methods in filtering out trees and buildings from a DSM so as to come up with a reliable DEM? What I have is a grid from a LIDAR data (.tif file, with 1m resolution). I was going ...
6
votes
2answers
768 views

How to de-noise a DSM

I have created a DEM, DSM, and nDSM from a LiDAR Point Cloud using SAGA-GIS. I extracted the appropriate returns from the point cloud, then converted to grid, and then closed gaps to fill in any ...
1
vote
1answer
111 views

SRTM DEM and satellite DEM fusion

I have a SRTM DEM and a DEM derived from satellite (Cartosat). Both the DEMs are registered perfectly. Now I want to carry out a DEM 'fusion' process to derive a higher quality output DEM. I am not ...
3
votes
1answer
88 views

Calculate Volume over sloped ground in GRASS GIS

I am trying to do some volume calculations on a DEM with GRASS GIS. However, I believe r.volume measures everything from 0. The ground underneath the pile I'm measuring is sloped. I would ...
3
votes
1answer
95 views

How to exclude water during contour generation?

I recently acquired a LiDAR data set that included a 1 meter DEM. I generated 1, 2 and 5m contour layers but I am seeing a lot of contours within water bodies. I suspect this is either caused by wave ...
6
votes
1answer
158 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 ...
0
votes
0answers
30 views

QGIS problem with converting TIFF-DEM to ASCII

I converted a .tiff DSM into an .asc file. The output-file is stretched increasingly from th the upper to lower part (the dark structure under the classified DEM is the .asc-file). What went wrong? ...