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Questions tagged [dem]

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

0
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1answer
11 views

CSMapMaker QGIS Plugin - anything similar for ArcGIS?

I'm looking for a tool or script or set of operations to mimic the output from a certain QGIS plugin called CSMapMaker, wherein curvature, slope, and a gaussian filtered DEM are overlain one another ...
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1answer
11 views

Using Ground Control Points in Agisoft Photoscan?

I'm fairly new to the Agisoft Photoscan program, but I am trying to build several models using aerial imagery and highly accurate GCPs, with coordinates collected in the field. I align my photos and ...
1
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1answer
43 views

Raster Volume Returning Wrong Volume

I have a clipped surface using Washington State Plane North (feet) added to a QGIS project using the same CRS. I am trying to calculate the area under this surface (a dirt pile) using SAGA Raster ...
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0answers
17 views

Performing raster neighbour analysis? [on hold]

I am currently working on a raster dataset with height values. The dataset represent a bathymatric profile of a coastal area. I need to identify sandbars within the dataset, by its shape. (So higher ...
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1answer
50 views

DEM not showing when loaded

I'm very new to QGIS, but in the past days I've created 3 different maps. I have now downloaded DEM data in ASC format, and when I open it as a raster file in a new QGIS project there is no problem, I ...
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0answers
10 views

When asked to select raster for elevation (in 3D configuration/QGIS) will be the DEM raster as downloaded or DEM raster re projected?

Do you need to re-project Aster GDEM data from USGS Explorer into a metric coordinate system in order to be able to view a map in 3d mode in QGIS? Or you just use the file input as it is downloaded ...
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0answers
22 views

Set elevation value of vector layer based on DEM/contours using QGIS [closed]

Is there a way to set the elevation values of a vector layer that is not based on a DEM or the contour lines extracted from it? I'm trying to set a road on a slope and then elaborate a CAD drawing.
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0answers
10 views

Projection of a precipitation map over DEM [closed]

If I have precipication rate over a surface using azimuthal projection from proj4 library. How can I map this data on a digital elevation model? How can I know the rainfall rate over each grid cell of ...
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0answers
14 views

Wrong value classification DTM ArcGIS

This DTM has mainly values between 0.7 and -0.7 (see histogram). In QGis it is displayed propper. In ArcGIS (10.5), although the histogram is okay, it displays values in the range between 8 and -8.
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1answer
28 views

Open TIN DEM File format

Anyone know a TIN DEM file format commonly used? In the context of a TIN DEM generator project, I am searching for a file format to save the TIN generated.
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3answers
47 views

Problem with CRS metadata for UK Environment Agency LiDAR DSM tiles?

I have downloaded some LIDAR DSM composite tiles from https://environment.data.gov.uk/DefraDataDownload/?Mode=survey and opened them in QGIS 3.6 with project CRS set to OSGB 1936 (EPSG:27700). ...
1
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1answer
51 views

Resample/Increase the resolution of Digital Elevation Model by QGIS [closed]

I have a DEM of 5m pixel. I wonder is it okay to convert it to 2m pixel? How to do that using QGIS? And what would happen to the original data, I mean the accuracy? Would it be reliable?
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1answer
10 views

CGIAR DEM converted to XYZ consists of Nodata only

I have a 30-by-30 tile from http://srtm.csi.cgiar.org/srtmdata/ Later I pre-process as outlined in the previous question CGIAR DEM + gdalwarp -- projection to Cartesian is not happening (see the ...
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1answer
12 views

CGIAR DEM + gdalwarp — projection to Cartesian is not happening

I have downloaded a 30-by-30 tile from http://srtm.csi.cgiar.org/srtmdata/ Then gdalinfo on the obtained single *.tif-file would yield Driver: GTiff/GeoTIFF Files: cut_n30e000.tif ...
1
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1answer
23 views

UTM Projection of DEM-data with gdalwarp

I have downloaded a certain tile from https://www.eorc.jaxa.jp/ALOS/en/aw3d30/data/index.htm, and after the requisite logistics (unzipping, putting all *.AVE_DSM.tif files into a single folder), I ...
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0answers
14 views

Howerive vector stream network from a DEM using D-Infinity Flow Direction algorithm?

I have been working with a 1m LiDAR derived DEM to create a vector stream network. Using the D8 flow direction, D8 flow accumulation, and a specified threshold, I was able to create a vector stream ...
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0answers
5 views

Getting 3D polygon to reach next isoline using ArcScene 10.5

I have a flood innundation polygon and the DEM used to generate it. I've added the Z coordinates for the innundation shapefile from the DEM, but I need to get it to reach the next isoline which ...
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0answers
35 views

Mars DEM: Interpretation

I have processed the *.tif-file from https://astrogeology.usgs.gov/search/map/Mars/GlobalSurveyor/MOLA/Mars_MGS_MOLA_DEM_mosaic_global_463m as gdalbuildvrt mars.vrt <filename>, and now gdalinfo ...
1
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1answer
44 views

GDAL: gdallocationinfo of CGIAR mosaic elevation data

I have downloaded tiles from http://srtm.csi.cgiar.org/srtmdata/ and unpacked the *.zip files into a directory. Then I ran, as has been suggested here: CGIAR SRTM to xyz using GRASS GIS, with ...
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0answers
16 views

How to open G.L.O.B.E. DEM files from NOAA

I need to open a free GLOBE DEM. I have downloaded some tiles from: https://www.ngdc.noaa.gov/mgg/topo/gltiles.html, but I don't know which software should I use in order to open those files. Is ...
0
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1answer
19 views

How to open a .dem file properly?

I have this DEM file downloaded from the internet. It's a text-formatted file and it looks like this: 1440 720 30 -9999 450 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -...
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1answer
41 views

QGIS 3.4 Stream delineation problem, lines running too far into ocean

I am using QGIS 3.4.4 Madeira version trying to delineate the stream and catchment areas of a small Bay in Honduras based on the technique of Hanz van der kwast tutorial "Stream and Catchment ...
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0answers
46 views

Extracting Ridges from DEM ALOS

I'm currently working on a forestry project for my thesis. It consists of the optimization of skids tracks planification using ALOS images. To this end I would like to extract obstacles such as steep ...
0
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1answer
30 views

Slope is not consistent with the elevation of DEM and seems to be incorrect

I have a DEM image which shows the elevation is from approx. 81 to 103. I expected the slope should be 0-22m. However, the result from DEM-Terrain Model-Slope is from 2.5 to 13.2. Anyone knows why?
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0answers
20 views

Calculating canopy model (CHM) using QGIS Raster Calculator?

Is it possible to calculate canopy model (CHM) with raster calculator from such input data? (DSM1 + DSM2 + DSMn) - DTM Or, is it necessary to merge DSMs first?
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0answers
26 views

Quantitatively evaluating quality of watershed delineation stream line results?

How can we quantitatively describe the quality of watershed delineation? What metrics can I use to compare the stream line differences between a few delineations using different DEMs with different ...
1
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1answer
26 views

Adding height to dam in ArcGIS Desktop?

I'm having issues with flow direction in a reservoir heading in both directions. To try and correct this I think I need to add height to the portion of the DEM that currently represents the dam to ...
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0answers
27 views

Fixing sharp edges between GeoTIFF tiles? [duplicate]

I've downloaded a couple SRTM DEMS from http://srtm.csi.cgiar.org and when I load some of them into QGIS, there is a noticeable edge between 2 of the tiles (see image). Why does it happen? These are ...
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0answers
28 views

GdalDEM slope error in Jupyter

I try to calculate slope data. This is the DEM source https://www.earthenv.org/DEM Firstly, I translate data with gdal.Warp according to image UTM zone. Original image .bil extension so first I ...
1
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1answer
26 views

Applying same symbology to different DEMs?

I am using ArcScene and ran into this problem where I downloaded a couple of neighboring/bordering DEMs(in BIL format), imported them into the scene (as separate entities) and applied Base Heights so ...
6
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2answers
151 views

Raster antialiasing

I am looking for a way to antialias integer DEM data (hgt file) to float GeoTIFF. That way I want to avoid gdaldem hillshade artefact lines which you can see in this picture: I don't want to blur ...
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0answers
37 views

QGIS Exporting Layout as Blank PDF?

I am trying to export my map layout in QGIS3.4.5 on OSX 10.14. I've made the layout look exactly how I want it to look, but whenever I export to PDF, the PDF file is just a blank white page. The ...
2
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1answer
47 views

Mirrored Contours from DEM in QGIS

I am trying to create contours from a DEM in QGIS 3.4. I used the GDAL raster extraction contour tool. The contours are drawn correctly, but they are mirrored along the north line of the DEM (see ...
0
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1answer
49 views

Find higher elevation (10m) perpendicular point from stream network at regular interval

I have a stream network and for that network, I want to find the points at regular intervals which lie at 10m distance perpendicular from the stream.The final goal is to find the buffer of that 10m ...
2
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1answer
48 views

sampling error using gdalwarp on a subsetted VRT?

I am currently trying to prepare an SRTM subset including height conversion from EGM96 to WGS84 using gdalwarp. I encountered some strange shifts in part of the image. Here is a reproducible example: ...
2
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0answers
102 views

Increasing zoom level in 3D View QGIS Desktop?

I would like to increase the zoom level for my mosaic raster image in the 3D View of QGIS Desktop 3.4.4. I made a mosaic out of four raster images downloaded through the STRM-plugin for DEM data. ...
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0answers
20 views

How do I compare multiple years worth of geomorph changes in a river while drawing one profile line?

I have many years worth of DEMs of a river I'm studying. I'm very, very new to ArcGIS (think one intro class), and learned how to use the 3D analyst tool. What I'd like to be able to do, is to draw ...
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0answers
50 views

Easy way in PyQGIS to convert a distance from meters to coordinates?

I am attempting to clip DEM rasters (USGS, in WGS 84) into a set of tiles measuring 2.56km on a side, in QGIS, using python. So far, it appears that gdal_translate is working for me, using a ...
0
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1answer
35 views

How to generate DEM Generation in LPS

I have a Cartosat 2.5 m Imagery and Block files along with DSM Data. I wanted to generate DEM using Leica Photogrammetry Suite Software. Does anyone know the steps of generating same? I have to edit ...
2
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1answer
29 views

FME Surface Modeller “minimum number of points”

IN FME workbench 2016.1 I want to create a DEM from Multipatch-geometry contained in a geodatabase, for doing that I thought using the SurfaceModeller could work, where in SurfaceModeller I group the ...
0
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1answer
25 views

Converting IMG to BIL/HRD/BLW?

I'm trying to convert IMG data from USGS's 1/9 arc second DEM to something that Pathloss 5 can read. Is there a way to do so?
1
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2answers
81 views

Visibility analysis with mask for non visible areas?

I have LiDAR data and I've made a Digital Surface Model (DSM): I've made a visibility analysis for 3 buildings with this model: My goal is to know from where the buildings are visible, not what do ...
0
votes
1answer
34 views

Extract height from DTM into attribute table of point layer [duplicate]

I am using ArcGIS Desktop 10.4 I have an empty point layer (100 random points) and a dtm. I was wondering how I would go about to get the height from the dtm underneath each point into the points ...
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0answers
27 views

Whitebox GAT branch depression big raster

I'm trying to run the tool Brunch depression form Whitebox GAT but the process doesn't work probably because the DEM is oversize For generate that raster i converted the single quadrant in the ...
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1answer
50 views

Highest point from DEM

I generated the next DEM abd Orthomosaic and I am interested in extract the highest point of each building, is there any workwflow that I could implement in QGIS or SAGAGIS
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0answers
26 views

Filling NoData around bridges in DEM

Is it possible to fill no data around bridges without pixels blurriness (see picture). I use Elevation Void fill function, also tried in qgis No data filling and Grassgis r.fillnulls. I know, that I ...
2
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1answer
52 views

Translating vector by raster DEM data in QGIS?

I'm trying to follow the set of instructions here: https://twitter.com/imhere_asia/status/1023055838787690496 [EDIT] Pasting the instructions here for reference so people can avoid twitter. ...
2
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0answers
32 views

Channel network from high resolution DEM for flat areas

I'm working on channel network extraction from a LiDAR DEM (square grid max resolution 0,25 cm), and my area of study is vary flat with some part below the sea level. I applied the classical valley ...
1
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0answers
62 views

Difference between DEM raster in QGIS 2.18 and 3.4.4 [duplicate]

I came across a really strange problem. Untill today i always worked in QGIS 2.18. Now i wanted to upgraded to 3.4.4 ( it was already downloaded but hadn't used it yet) When opening my QGIS ...
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0answers
15 views

Creating 3D Local Scene using pointcloud, DSM, and orthomosaic from Drone in ArcGIS Pro?

I am trying to create a local 3D scene in ArcGIS Pro and display data fro drone flights. I have the orthomosaic from the flight as a .tif, the Digital Surface Model as a .tif, and my pointcloud from ...