For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)

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9
votes
7answers
41k views

Extracting raster DEM elevations to vector attribute tables in ArcGIS Desktop?

I have an ArcMap 10 project with multiple layer groups. One layer is a raster DEM, another layer group is a bunch of vector shapefiles (including points, lines and polygons). The client wants all ...
0
votes
0answers
19 views

Elevation data from floating point DEM in ArcGIS for Desktop? [duplicate]

I have acquired a DEM from local municipality. It is a float point DEM, and the elevation of each pixel is represented as simply "pixel value". What would be the correct work flow to convert this to ...
3
votes
2answers
323 views

Creating DEM from las file without using Lastools

I want to create a ground model from a *.las file. The LAStools are available in QGIS but limited in use (generation of black diagonal in result file), so I can't use this. In the GRASS tools I can ...
3
votes
2answers
905 views

Canopy Height Model of LiDAR data in QGIS?

I am having a DTM and DSM files. I want to develop a Canopy Height Model in QGIS. Is it possible?
-2
votes
1answer
64 views

Expression into the raster calculator to invert DEM

I've made a DEM from first pass LiDAR data which I want to invert and run watershed segmentation and basin delineation over in order to hopefully extract tree canopy outlines and heights - I'm newish ...
1
vote
2answers
128 views

Trouble “extracting by mask” with a DEM layer and a shapefile?

I'm using ArcMap 10.2 and I'm currently trying to clip a county-wide DEM layer (.lyr file) down to a smaller area using a shapefile. The data frame coordinates system is set to US Feet which is what I ...
4
votes
1answer
51 views

The source of and possible solutions for DEM anomalies?

I am working with a DSM (Digital Surface Model) created using stereo-paired spot 6/7 satellite imagery. This DSM, and metrics derived from it will be used to create a Predictive Ecosystem Map (PEM). ...
1
vote
1answer
2k views

Fill sinks error in arcHydro

I am working on a project that is modeling runoff at a county level. The DEM used is lidar derived and has a 5 ft resolution. The general workflow I am flowing is Sink evaluation Sink Selection (to ...
1
vote
2answers
111 views

Filling up river corridors in a DEM

I'm currently working with a DEM (10 m x 10 m resolution) that has a lot of faulty elevation values in river corridors. In order to run a hydrodynamic model I'm trying to get the following done in an ...
23
votes
8answers
2k views

How to generate a random but believable digital elevation model?

Is there a way to generate a DEM, programatically or otherwise (arcpy or R?), that will feed into ArcGIS for further spatial analysis? Perhaps this needs to be broken down into smaller incremental ...
0
votes
2answers
596 views

How do I find the slope of road segments with point elevation data of the same linear path

I'm currently working on a project to calculate road grade along roughly 30 miles of highway. I need to isolate and portray all sections of road with more than a 5 percent grade; in hopes of finding ...
2
votes
1answer
119 views

Reclassifying a DEM using ArcMap 10.1

I have a DEM that am reclassifying into two classes. One areas less than or equal to 1000 and the other areas greater than 1000. Am accomplishing this using the reclassify Tool in ArcMap 10.1. The ...
2
votes
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 ...
21
votes
4answers
17k 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
50 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
votes
0answers
68 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
63 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
93 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
94 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
44 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
49 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
136 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
548 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
44 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
51 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
1answer
106 views

Reset a base elevation in Pix4D?

Does anyone know how to set a baseline elevation in Pix4D, or is that something that has to happen on the drone-capturing side? The reason is that I have an area which is flown with LiDAR, several ...
0
votes
2answers
113 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
42 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 -3....
4
votes
0answers
71 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 ....
0
votes
1answer
88 views

Where can I find SRTM DSMs (digital surface model)?

I'm interested in finding a 30 meter DSM (digital surface model that includes canopy) from SRTM with the hope of creating a 30 meter canopy height model. I know that it can be done because the ...
2
votes
2answers
380 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
29 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
74 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
82 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
649 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
72 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 ...
0
votes
1answer
53 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
869 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
14 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
58 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 ...