Questions tagged [dem]
For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)
1,292 questions
0
votes
1answer
32 views
SRTM/DEM 1m resolution (batymetri) to point
I have bathymetry data (1 huge data) =
SRTM/DEM/FGDBRaster (0,9818m resolution pixel, floating, 32 bit, 45 GB size)
and an alternative data (split into small pieces data) =
same data but with 1m ...
0
votes
0answers
19 views
Smoothing contour ArcMap
I have an SRTM/DEM. I need to convert that data into contour with 1m interval elevation (using ArcMap). When I export to point to check the data of my SRTM, the data has interval 1m horizontal each ...
-3
votes
0answers
19 views
DEM generation from Tri-stereo optical images [on hold]
I have Tri-stereo optical images of Pleiades data, in primary mode. I want prepare DEM and orthophoto. Is there any workflow in OTB?
0
votes
1answer
40 views
Origin of LandViewer DEMs?
does anyone know how DEMs that can be downloaded from LandViewer are generated?
They have higher resolution than SRTM and other free sources.
-1
votes
0answers
16 views
0
votes
1answer
27 views
Determining elevation of a point from a DEM in QGIS?
I have created a series of DEMs that layercake on top of each other.
I would like to be able to lookup a coordinate and get the elevation that has already been interpolated. The goal is to ...
0
votes
3answers
59 views
Have DEM, need polygon outlining region above a certain elevation
I have a DEM in HGT format. I need to isolate all areas above a certain elevation and view them as polygons. Something like this (let's say the pink polygon is everything above 1000m):
Seems like ...
0
votes
0answers
21 views
Increase DEM resolution in QGIS2threejs
I use QGIS and QGIS2threejs-plugin for quite a while. In context of a current project I need to increase the resolution of the DEM over the whole project area - the right end of the "resampling simple ...
0
votes
0answers
15 views
Z-Value referencing in QGIS
I have calculated two DTM models and the belonging orthophotos of the same area in Agisoft PhotoScan to compare the before- and after-state of an excavation using QGIS. The X- and Y-position of all ...
-1
votes
0answers
49 views
Using Hydrologic Analysis to delineate drainage areas using SAGA?
I have a question regarding hydrologic analysis using QGIS/SAGA. I have used them to delineate drainage areas for a few projects at work. I tried to do the same for a current project and have run into ...
0
votes
0answers
30 views
Export 32 bit raster image
I'm trying to merge DEM rasters of US-wide using Arcmap. I use 30m DEM rasters from the NRCS Data Gateway. I created mosaic-dateset then I added all rasters in it. When i try to merge all of the ...
1
vote
1answer
19 views
'Regular Points' vector layer in Bonn
I've downloaded the bonn version of QGIS. Using the 'regular points' vector analysis tool, I've set some 5m regular points over a field so that I can use the x,y coordinates to plot them and measure ...
0
votes
1answer
26 views
Converting DEM units using Map Algebra and Python
I am trying to write a bit of code that combines a bunch of DEMs that match up perfectly and convert the elevation values of the pixel cells from meters to feet. This is all using Pyscripter and ...
0
votes
1answer
25 views
Extracting DEM from PRISM data?
I have PRISM data which is in the following format.
Are there any ways (software and methods) to extract the DEM or elevation information from these data files?
5
votes
1answer
115 views
Setting the same min/max for multiple raster layers QGIS
I have 268 hgt-files from Viewfinder Panorama that I'm using to create an elevation model, but each of the files has its own min and max-value in Layer Properties - Symbology - Band Rendering.
...
0
votes
0answers
37 views
ImageMosaic plugin for DEM rasters on Geoserver
I'm using 30m DEM rasters from the NRCS Data Gateway. I use image mosaic to merge them. But when i preview i see black gaps between rasters.
Coverager Parameters:
How can i remove that black gaps?
0
votes
2answers
42 views
DEM from Vector to Raster in GRASS GIS
I am using GRASS GIS 7.4 and I have a DEM as points in a vector format and want to turn it into a raster.
I tried using v.to.rast and v.to.rast3, but the elevation is not one of the attributes so am ...
2
votes
2answers
34 views
QGIS Python Discrete ColorBand Classification
I'm trying to automate a process where we bring in a DEM, extract the contours as a new vector layer, then set the dem to render the band between each contour line a separate colour.
I want to do is ...
0
votes
2answers
37 views
DEM's from Baja, Mexico [closed]
I need to extend my digital elevation map (10m or 30m will do) into Baja from southern CA.
1
vote
1answer
60 views
Efficient downsampling with GDAL?
I have a 350go GeoTIFF file with DEM data for the entire world. (a mix of SRTM, EUDEM, etc. ...)
This TIFF file is tiled with a block size of 256*256.
I would like to downsample this file to a lower ...
1
vote
2answers
83 views
Strange Pattern in LIDAR derived DSM raster
I produced a DSM raster from LIDAR data for eastern Kentucky. There are strange lines from southwest to northeast. Do you have any idea what those might be?
I generated the DSM raster with both first ...
7
votes
1answer
148 views
Can LINESTRING “contain” POINT?
According to Wikipedia,
The predicates Contains and Within have subtle aspects to their definition which are contrary to intuition. For example,[10] a line L which is completely contained in the ...
1
vote
0answers
20 views
Orthorectification on a DSM
I would like to orthorectify on the features (trees and buildings), noted that with may cause some stretching or tearing on the image due to the obliquity of the look angle. I'm only interested in top ...
0
votes
0answers
22 views
From DEM resolution/precision what limit to contour lines altimetric range?
I got a 1m resolution DEM: what is the altimetric range limit of contour lines I can create from it?
Not only the resolution needs to be taken into account but precision as well.
For now, I did not ...
1
vote
1answer
51 views
QGIS Issue with 3D view altitude binding
I'm running into an issue with the 3D view in QGIS.
I have a DEM, which is displaying correctly and a building footprints polygon layer from OSM. It is draping correctly as a 2d polygon on the DEM in ...
2
votes
0answers
38 views
World DEM speckled outcome solution
I have a world digital elevation model which has been classified into 5 showing the different heights.
My issue is that viewing and printing this image as it is results in a speckled look due to the ...
4
votes
2answers
98 views
Interpolate smoothly nodata values in QGIS
I have a DEM raster where all the buildings have been extruded and now contain "nodata" values. I'd like fill the holes and get a nice and continuous surface (which would approximately correspond to ...
1
vote
0answers
38 views
Edit a raster (DEM) to create a constant slope angle
I'm trying to edit a raster (DEM) that has square sides (90 degrees) to create a surface with a constant slope angle of 18 degrees.
I'm working in QGIS and have not been able to find any help for ...
0
votes
3answers
67 views
Changing coordinate of point shapefile in ArcGIS using ArcPy? [closed]
I'm working on coding a function in ArcGIS trying to measure the number of pixels between a point (feature class) and its nearest building horizontally within a UDEM raster, then return the number.
...
3
votes
1answer
75 views
Alternatives to cesium terrain builder?
Looks like cesium-terrain-builder still have this issue and can't be used for large projects, so I wonder if there any alternatives to cesium-terrain-builder that can produce DEM tiles, can work with ...
0
votes
0answers
40 views
How to interpolate ibutton transect temperature data ArcGIS
I have three transects on opposing slopes. Each transect has ibutton data loggers set to record temperature at hourly intervals. The loggers are spaced at 20m altitudinal intervals from 1550 - 1810m (...
0
votes
0answers
17 views
Building cache from DEM
I have problems figuring out the best way to build a cache from a DEM.
Is it possible to build Cache so that it is optimized for the current display extent, as many details will be lost if this ...
0
votes
0answers
25 views
QGIS DEM files do not behave the same way using the Viewshed Analysis plugin
Software and platform:
QGIS 2.18.20
Windows 10 pro
My issue is as follow:
I am doing a Viewshed Analysis of a single site, where multiple DEM files (*.img if it makes a difference) are needed.
I ...
0
votes
1answer
107 views
DEM reconditioning?
I'm using ArcGIS Desktop 10.5 Arc Hydro Toolbox & encountered a problem while trying to delineate watersheds respectively drainage lines.
The red lines indicate my obtained drainage lines, which ...
0
votes
0answers
53 views
Rasterio Raster merge - horrible result
I am merging .DEM files from CUGIR NY repository, and need to merge files into one larger image for the whole of NY city. I use python 3.6 + rasterio; It works perfectly for all but one file - "The ...
2
votes
2answers
41 views
Flatten broad area through road fill connecting upstream and downstream
What are some recommended approaches for flattening a broad area through a road, as a means of connecting the upstream and downstream parts of a stream bed?
I am not trying to connect these areas for ...
1
vote
0answers
37 views
How can I merge a DEM mosaic with an overlapping bathymetry raster (while keeping only the portions of each that I want)?
I am tasked with merging a bathymetry raster with a mosaic raster I created from ArcGrid DEM Tiles downloaded from the National Map, for an areal extent spanning the Coastal Lowlands Aquifer System.
...
0
votes
0answers
46 views
Shapefile with data into Unity?
So far I have imported my GeoTIFF as a height map (raw) into unity.
The simplest solution to getting the road map shapefile on was to set it up as a PNG texture and layer it on. This worked well, BUT ...
2
votes
1answer
57 views
Usage of interpolation methods with DEMs: Linear vs. natural neighbors
Using the ArcGIS tool "TIN to Raster" (3D Analyst Tools --> Conversion --> From TIN) to work on my Digital Elevation Model I was wondering about the interpolation methods.
I can choose either or:
...
1
vote
0answers
15 views
Points on the opposing side of a breakline
If you have a breakline or even a single line segment within a DEM, how can you tell if two points lie on the opposing side of that breakline or line segment? From a computational geometry standpoint ...
1
vote
1answer
78 views
GeoTiff import appears to be flat in BlenderGIS
I an very new to GIS and I am trying to import a GeoTiff file into Blender to view it as a model before importing into unity. For some reason when I import the file into blender as a raw DEM it ...
1
vote
1answer
111 views
How to open .hgts file from NASADEM data
I have the NASA SRTM1 data as .hgt files from their ftp website, but I would have these elevation data in respect to WGS84. I found by NASA's ftp site a folder named srtmOnly that contains what I want,...
1
vote
1answer
29 views
Find intersection of multiple DSM's using Python and GDAL
I am quite a beginner in respect to GIS and hopefully someone can help me out with the problem I have.
I have multiple digital surface models [DSMs] of the same area with all necessary geo-...
2
votes
0answers
37 views
Adaptive raster to points sampling based on change of slope in QGIS?
I have a high resolution elevation map and need to convert it to XYZ points. Simple conversion generates a lot of points in flat / constant slope areas which are redundant for 3D terrain generation. ...
1
vote
1answer
92 views
Using Color Ramp Manager Plugin in QGIS?
I followed instructions mentioned here and installed the Color Ramp Manager by choosing install experimental plugins as well.
Now, when I go to Properties > Style > Single Band PsuedoColor and I ...
0
votes
1answer
29 views
How to save NDVI TIFF file as txt file in ArcGIS?
Basically, I have to use elevation data (dem.tif) and NDVI data (ndvi.tif) as covariates for regression kriging and I want both these files as txt files.
Please guide me how to do this.
0
votes
0answers
9 views
Mosaic multiple slope files
I am trying to mosaic multiple slope files into one large slope file. What is the best tool to use? I have tried mosaic to new raster but the values change from multiple decimal points to whole ...
1
vote
1answer
51 views
Generalizing slope raster in Mapinfo?
I am working on calculating a slope raster in Mapinfo using a 15cm DEM derived from a LiDAR point cloud and the output data will have 3 predefined breaks displayed so I need to blur those relatively ...
1
vote
0answers
271 views
Openlayers in QGIS - Errors in opening google satellite/
End goal: To put contour lines with lat&long layers from a google earth location (Rock Piles beach, HI) in QGIS. I plan to use CRS: EPSG:3760
Does the Plug in (Openlayers / QuickMapServices) ...
0
votes
0answers
21 views
Reduce or heighten a DTM with overlaying polygons
I am using QGIS 3.01.
I have a DTM over a historic area. There has been done archaeological surveys there, which suggest that the ground was several meteres below todays surface many hundred years ...
