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Questions tagged [dem]

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

2
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1answer
21 views

DEM of difference - estimate the error - simple method

I have two DEMs of the same area, measured at two different dates. Subtracting one from the other, I can create a DEM of difference (DoD) to find out about the volumetric change in m³. DEM 1 has a ...
1
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0answers
23 views

White grid appears when reprojecting DEM in ArcGIS Desktop?

I am using ArcGIS Desktop 10.5. I have a DEM .tif archive, in WGS 84. The specifics are: Then, I try to reproject it to WGS 84 UTM 19S. Project and transformations -> Raster-> Project Raster I use ...
0
votes
0answers
14 views

How to Calculate area of LULC at different elevation by using zonal statistics as table tool

I have to calculate the area of different land classes like forest,barren land etc from my classified land use data at different elevation zones at an interval of 100m. I have DEM of my study area ...
0
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0answers
22 views

Is there any way to vertical georeference the DSM number 2 based on DSM number 1?

Saying a have two DSM from the same location in Nepal, but they were acquired from different methods and have different elevations. It is not constant, so I cannot use the raster calculator in QGIS to ...
0
votes
1answer
23 views

Creating DEM from mesh? [duplicate]

I have a mesh ( with points and triangles that define it), and I will need to create a DEM model out of it ( in geotiff format if possible for space consideration, if not, then in ASCII grid format). ...
-2
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0answers
35 views

How to Align two different DSMs

I've tried to align 2 DSMs without success. They should have the same elevation (I got 1 DSM BEFORE a landslide and other AFTER) excluding areas where soil was moved, the DSMs do not match. They have ...
-1
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0answers
31 views

Adding General slope in DEM using ArcGIS Desktop? [closed]

I am looking for a solution to increase general slope of DEM in ArcGIS Desktop like this: Any idea?
1
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2answers
51 views

How do I combine these two rasters?

I have a raster representing rivers/drainage basins within a terrain: I have a raster DEM of the terrain: In the basin raster, everything in black is 9999. White is nodata. The DEM is obviously a ...
1
vote
1answer
64 views

How can I use line vectors to alter my DEM?

I'm trying to use vector lines to change the height of the areas of my DEM that they overlay. They trace rivers, and i'm hoping to assign arbitrarily high values to the rivers so that my least-cost ...
1
vote
1answer
31 views

How do I create a binary mask using Pixel values from a Numpy Array over a certain value (i.e. >1000), in Python [closed]

I would like to create a binary mask using the height values from a Digital Elevation Model, and export this out as a tif. For example, generate a mask for areas over 50m My code so far: from osgeo ...
0
votes
0answers
54 views

DEM - calculate shortest/easiest path over mountain range [duplicate]

In QGIS, I have a mountain range with a valley on either side (DEM raster file). Is there software or a plugin that allows me to calculate the easiest pathway over the mountain? The answers at Cost ...
0
votes
1answer
28 views

Getting grid points for DEM purpose that is bounded by surveyor points?

I have a list of surveyor points, and I will need to create a DEM model out of it ( in geotiff format if possible for space consideration, if not, then in ASCII grid format). I need the DEM for ...
0
votes
1answer
27 views

Reclassify with attribute

So, I don't really know how to word what I want to ask, but I took a DEM file and did used the raster calculator to select a certain elevation range. After that I reclassified it to separate it into ...
0
votes
1answer
48 views

Converting RTK Elevation Data to DEM?

I have a shapefile that contains elevation data. I want to eventually convert this to a slope layer. I'm assuming I have to convert to a raster, then a DEM, then slope. Is that correct? If so, ...
2
votes
1answer
54 views

Interpreting x, y coordinates from ASCII elevation data?

I'm using Environment Agency DTM LiDAR data which I import into Mathematica in ASCII format to produce ground surface models, sections, etc. The process works fine, but I'm unclear whether the cell ...
0
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0answers
9 views

Interpretation of digital surface model (DSM) built from s2p tool and XML file

I am new to GIS. I am using s2p stereo pipeline to build Digital Surface Model (DSM.tif) from it. The height of certain point in this DSM.tif is 84 meters, and you can see from the color bar on ...
4
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0answers
33 views

Using NAVD88 geoid in Northern Canada?

The USGS NED (1-arcsec) dataset is available for the continental US as well as most of Canada. It is based on the NAVD88 vertical datum. I am interested in using the DEM to orthorectify SAR scenes in ...
0
votes
1answer
15 views

Image not draping over DEM in ArcScene?

I saw Images not draping onto DEM in ArcScene? but it is different from my issue. I have an image with projection: NAD_1983_StatePlane_Oregon_North_FIPS_3601_Feet. I have a DEM and set the base ...
0
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0answers
53 views

Modeling hole in DEM using QGIS?

I have a DEM raster. I have a polygon representing a hole. How do I combine the two, so that I have a new DEM whose elevation, in the area bounded by the polygon, has been adjusted according to ...
0
votes
1answer
59 views

Extracting certain area from DEM?

How to extract a certain area (uniform 1 km from the entire coastline) from a particular year's DEM image? How to cut a uniform distance of 1 km from the right coastline DEM below?
2
votes
1answer
28 views

Error in orthorectification of Radarsat-2 scenes with GDAL and RPC + DEM information

I am trying to use a DEM rational polynomial coefficient (RPC) information to orthorectify radarsat-2 images with GDAL 2.2.1. I have successfully done this with Orbview-3 images using the tutorial ...
2
votes
1answer
113 views

Why ground model from point cloud in Global Mapper is inaccurate?

I have a LAS file that I assumed was based on LiDAR, but it is actually based on ADS (airborne digital sensor) imagery, according to the body that captured the data. I load the file in to Global ...
0
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0answers
11 views

Using Socet set to Merge?

I have been trying to merge an 8m DTM to TIN, and I have been finding the issue where socet loses mass amount of points in the merging process. I have tried several times with different datasets and ...
0
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0answers
67 views

Drainage Line Processing in ArcHydro Tools

I have a question regarding the ArcHydro Tools: I'm delineating watersheds in an urban area. The drainage lines I obtain running the ArcHydro Tools do not match with the drainage system, that's why I ...
1
vote
2answers
65 views

Seeking for a solution to convert GeoTIFF to 3d WKT

I am trying to convert some DEM in .tif image to polygon geometries representing 3 dimensional triangles that is Well-known text (WKT) - 3D (x, y, z) I was able to use SAGA to convert my GeoTIFF ...
0
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1answer
20 views

DEM to bmp for cnc carving query

I'm importing grayscale elevation images (bmp and jpeg) into a program I use for 3d CNC terrain carving. I've been downloading Hi-Res terrain corrected DEM files from ALOS PALSAR. I bring them into ER ...
1
vote
1answer
67 views

Combing multiple LAS files with different vertical and horizontal accuracy?

The data set in question was made using .las and .zlas files from respectable sources. Data set 1 was collected in the Fall of 2014. The RAW flight line swath data was processed to create classified ...
0
votes
1answer
24 views

EU DEM in GRS80 EVRS2000 with geoid EGG08 --> Make it comparable to Black Sea 1975 for Romania

I got contour lines for western Romania in vertical system Black Sea 1975 which is based on elevation data with 100 m resolution. Now I would like to compare that to the EU DEM with higher resolution. ...
4
votes
1answer
39 views

Seeking algorithms for DEM generation? [closed]

What are the different algorithms employed for the generation of a Digital elevation model from images captured using an unmanned aerial vehicle ?
0
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2answers
57 views

Determining flood extents based on a daily flow? [closed]

I have a DEM raster and daily average flows (e.g., 50Ml/day). And I want to determine how far the water extent goes when the flow accumulates for 7 days based on 50 ml per day?
0
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0answers
15 views

Splitting lots of polygons to be used as DEM clipper? [duplicate]

i have 1 layer vector contain many polygon that overlap each other. i want to split these polygon into new layer for each polygon using ModelBuilder. What schema should i use on my ModelBuilder to ...
4
votes
1answer
91 views

Hack's law for river basins

The hacks law relates the longest stream length with the catchment area of the basin. How can one construct a hack's distribution for a basin and upto what scale the sub basins have to be taken as ...
0
votes
1answer
20 views

Error in change of projection from Lat/Long to UTM

Why does the the DEM when converted to UTM Zone 43N system give all values as 0 in QGIS? I followed the standard procedure of saving the parent layer and then assigning the CRS. When I open the same ...
2
votes
1answer
33 views

Working with NaN values in channel network in QGIS?

I have downloaded the conditioned 15s HYDROSHEDS dem of asia and after clipping the desired extent proceeded to evaluate the catchment area. However the next step of channel extraction renders NaN ...
1
vote
1answer
53 views

Converting GeoTIFF to USGS DEM or DTED using GDAL

I have been looking the documentation for gdal_translate and it doesn't list the -of format available options there. So I tried looking at the source and basically ended up read the SetFromUserInput ...
2
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0answers
19 views

Improving Sentinel 1 Interferometric DSM Accuracy - Removing Surface Anomalies

I have been working through the ASF's "Recipes" for the creation of a DSM from Sentinel 1 (A and B) imagery. I am able to produce a DSM, and am relatively happy with the results in terms of the ...
2
votes
1answer
39 views

Extracting Road Terrain Properties using DEM / LIDAR

I want to extract following road terrain data from DEM but I'm not sure if its possible. Can i extract these attributes using LIDAR if not DEM ? These are the data fields I need: Horizontal curve ...
0
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0answers
73 views

Extreme scaling issues with geo-referenced, edited heightmap

I am refining digital elevation files (GeoTiff format) using a tool that exports in a .RAW format. I then save the raw file as a .tif, georeference it using gdal, and import it into the rendering ...
-1
votes
1answer
57 views

SRTM/DEM 1m resolution (batymetri) to point [closed]

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
1answer
50 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
vote
1answer
39 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
4answers
82 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
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0answers
30 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
31 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
24 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
32 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
27 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
170 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
39 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
63 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 ...