Questions tagged [dem]

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

Filter by
Sorted by
Tagged with
0
votes
0answers
29 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
65 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
31 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
167 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
103 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
81 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 ...
1
vote
1answer
80 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
64 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
158 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
23 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
114 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
50 views

Generating 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
40 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
31 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
90 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
42 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
40 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
56 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
35 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
74 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
36 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
72 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
52 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 ...
3
votes
0answers
62 views

Problems with DEM exporting after Elevation Void Fill function use

I filled nodata values in DEM by Elevation Void Fill function, everything was ok, but when I exported it, the raster looks different (see picture above), how can I solve this problem? I also tried r....
2
votes
0answers
68 views

Importing several LiDAR (.las) files in GRASS using v.in.lidar?

I'm building a DEM of a terrain in GRASS and have 48 LiDAR (.las) files. I know I can do this by using r.in.lidar (including the list of files as a .txt) and then r.fillnulls However, I want to ...
0
votes
0answers
20 views

Assessing mapping accuracy of a DEM with different resolutions

I am mapping conical shaped depressions on the seafloor and would like to know at what resolution of the DEM is my mapping accuracy affected by. For example if I have a DEM of 7 metres, what does the ...
0
votes
1answer
248 views

Clip tool in ArcGIS Pro not working?

I'm trying to clip "Terrain" raster I downloaded from the portal (https://www.arcgis.com/home/item.html?id=58a541efc59545e6b7137f961d7de883) in the shape of a polygon (a country's boundaries) by using ...
1
vote
1answer
111 views

QGIS 3.4 and DEMto3D 2.3 Scaling Error

I'm having a scaling problem when using DEMto3D and extracting STL's for later manipulation. I have a merged TIFF file for Australia and am attempting to extract models of each state so I can print ...
0
votes
0answers
60 views

QGIS Display Attributes as Z Value for Point Shapefile?

I would like to create a state map that displays a 3D bar chart for each of 20 colleges (mapped as points) showing the percent share of engineering degrees earned by award level (i.e., assoc, ...
6
votes
1answer
281 views

Calculating shadow of trees with DEM in QGIS?

I have a DEM with a good precision (0,5 x 0,5 m/pix LiDAR) and I´m looking for the way to obtain a raster (or shapefile) with the shadow of the trees located in that place for a whole day (ideally ...
0
votes
0answers
73 views

Change detection using DEMs of difference and error quantification

Im currently working on a project in one of my seminars at university ("Advanced methods in natural hazard research"). We are modelling DEMs with Agisoft Photoscan using pictures from flume ...
1
vote
1answer
137 views

SAGA hydrology toolbox Error: select a library

Hi I am having trouble getting the SAGA hydrology toolbox running. Here when I try to fill sinks in the DEM a series of errors are flagged in the log file. This includes for 'select a library', 'DEM' ...
0
votes
0answers
16 views

DEM colour themes add-in for QGIS [duplicate]

Is there any plugins / add-ins for QGIS that give more of a variety than the default colour ramps?
0
votes
1answer
39 views

Viewshed Analysis for Custom DEM file [closed]

I am new to qgis and trying to do 2 things. My objective is to have an accurate viewshed analysis at the end. But my DEM file is of poor resolution. I do have a shapefile with building height ...
0
votes
0answers
16 views

Calculate average slope values for a point using 50ft vector perpendicular to contour

I am trying to calculate the average percent slope of a hillside on either site of a data point. I tried extracting info from a DEM using a radius around the point, but I believe a more accurate ...
0
votes
0answers
28 views

Creating DEM in GRASS?

I need to create DSM and DEM with resolution 0.4 m. I tried to create DSM with resolution of 1m, everything was ok, but when I set higher resolution, then raster have a stripes with No Data values. ...
0
votes
1answer
82 views

Merging 1m DEM to 30m DEM?

I have a base 30 m.Dem . However, i also have 1m Dem for an area of interest only. I would like to overlay the 1m Dem on the 30 m Dem meaning the area of interest will have 1m and the rest 30m. Is ...
1
vote
0answers
35 views

Creating Left and Right Image pair to view with 3D goggles in stereo from DEM or Hillshade?

How does one create the stereo pair for viewing in a program such as StereoPhoto Maker? I have processed lidar that I'd like to turn into hillshades and then view in this kind of software, with 3D ...
0
votes
1answer
66 views

Line of Sight Analysis using Points and DEM

I have a DEM and a point feature class with the elevation value from the DEM as an attribute plus with x number of feet added to it representing a tower location. I would like to do a line of sight ...
1
vote
1answer
99 views

Resampling 0.7 m LiDAR (in raster already) to 10 m DEM in R?

How do I resample the 0.7 m LiDAR to 10 m DEM in R? What are the basic rules for checking the consistency?
0
votes
0answers
35 views

How to retrieve GIS data in Multiple Orthophoto at point level

I have been using a python script that can read Data from Orthophoto(*.tiff) of size 300Mb-2Gb. But this is taking 32s per request of lat-long, which is not ok. I have different Orthophotos with ...
1
vote
0answers
80 views

ALOS/PALSAR High Q DEM 12.5 Accuracy

Does anyone know the XYZ accuracy for the Phased Array L-band Synthetic Aperture Radar (PALSAR) DEMs (12.5 x 12.5 px)? Is there a document for reference?
1
vote
0answers
23 views

AW3D30: DSM file is grayscale 32 bits?

I downloaded multiple areas in AW3D30, but each time, the DSM file is 32 bit (instead of 16 as indicated in the specs), and the 32 bits are grayscale with the alpha channel always to 255. (I'll be ...
0
votes
0answers
35 views

How can I change the elevation of a lake on a DEM so I show the lake bottom contours?

I'm studying the drainage of a lake and I have a DEM of the lake and the surrounding area. I already identified the shorelines of ancient lake levels at higher elevations, but I would like to keep ...
0
votes
0answers
41 views

Erroneous contour polygons in QGIS 3

I have a global DEM and try to calculate contour polygons for 4 different heights in QGIS. In the first image below, you can see the colored DEM (white = lowest; yellow = higher; orange = highest) as ...
0
votes
1answer
231 views

Reclassify and combine rasters in QGIS?

I have a vector layer containing watercourse location which I have rasterized. I also have a DEM containing elevation data for the region in which the watercourses are located. I would like to ...
5
votes
1answer
202 views

QGIS: Edit elevation in DTM to get correct slope of a river

I am new to QGIS and just need it to do a hydrolocic analysis of an area of which I later make a flow model with HEC-RAS 2D. I made it according to this tutorial: https://www.youtube.com/watch?v=Ro-...
0
votes
0answers
10 views

Creating terrain polygon buffer from line using ArcMap? [duplicate]

I have a line in a steep hill, and need a 400 meter buffer on each side of the line. I know (roughly) how to create buffer on a point, but not a line. Can someone help me here?
2
votes
2answers
87 views

Mapping coastline geometry with SRTM raster?

Working on a map that includes a bathymetry layer, SRTM data for hillshade, and an accurate coastline boundary edge. I noticed though that the pixel resolution of SRTM 90m resolution creates visible ...
0
votes
0answers
42 views

Smoothing/denoising DEM to prep for 3D printing?

My DEM was generated from contour lines (as well as break lines and point height data), and the contours persist in the DEM despite doing some basic denoising (although i may not have used the optimal ...