Questions tagged [dem]
For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)
0
votes
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 ...
0
votes
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
vote
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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.
0
votes
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 ...
0
votes
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.
0
votes
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.
0
votes
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
vote
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?
0
votes
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 ...
0
votes
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
vote
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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
vote
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 ...
0
votes
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
votes
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 -...
0
votes
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 ...
1
vote
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
votes
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?
-1
votes
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?
0
votes
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
vote
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 ...
0
votes
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 ...
0
votes
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
vote
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
votes
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 ...
1
vote
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
votes
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
votes
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
votes
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
votes
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. ...
1
vote
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 ...
1
vote
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
votes
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
votes
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
votes
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
vote
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 ...
0
votes
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 ...
1
vote
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
0
votes
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
votes
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
votes
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
vote
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 ...
0
votes
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 ...
