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
2
votes
1answer
42 views

QGIS: Burning stream network (catchment area)

I need help from stackexchange because of a DEM correction problem... I have a DEM with a 5 meters resolution where one of the main river is cut by a large highway. In order to delete that topology ...
1
vote
0answers
39 views

How to add elevation data to tif to create DEM (SRTM satellite data)

I have a .tif created from the SRTM satellite data. The tif should already be DEM data as it was collected from the SRTM satellite. When I open the tif in ArcGIS, I don't see any height or z data, ...
0
votes
0answers
17 views

Selecting pixels from a raster by value

I have two digital elevation model rasters. I calculated the difference of these two rasters using raster calculator and got a single output raster. Now I want to highlight areas where the surface has ...
1
vote
1answer
19 views

QGIS Rastercalculator: unexpected results for cos() function

I've calculated the slope values of a DEM and created a raster with values from 0 to 51,3 (degree). I wanted to calculate the Cos of these pixel values with the Raster calculator (to calculate in the ...
1
vote
1answer
21 views

QGIS, clip my vector data with a DEM raster

I know that I cannot simply clip vector data with raster data. I'm working in QGIS and I have vector point data of earthquakes (XYZ), and I have it projected on top of my raster data (.tif). However, ...
0
votes
0answers
21 views

How to remove slope from DEM to better visualise topographic features of vriver systems in QGIS

0 I have a DEM of a river channel that i would like to remove the overall slope but retain features such as pools, riffles, bars etc. I have used the River Bathymetry Toolkit (detrending tool https://...
1
vote
1answer
63 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 ...
0
votes
0answers
19 views

Calculating TWI after getting the flow direction, flow accumulation and slope

There are many tutorials online with this, but it seems that people use different equations and/or what they put into the general ln(a/(tanb)) equation. Do I need to know the cell size of the raster ...
0
votes
0answers
34 views

Watershed delineation using hydrological Python library

We would like to delineate watershed polygon for a given pour point using hydrological Python library. Until now, we have tried these libraries: pyshed Grass (r.watershed) Whitetoolbox We have ...
1
vote
1answer
224 views

Detrending DEM in floodplain?

I am after the same solution to Removing elevation trend over sloped surfaces? I am following the steps outlined, but in the last step it states: In this expression [X'] refers to the the x-...
-1
votes
0answers
14 views

Q: Scripting the generation of DEMs from Sentinel-1 imagery? [closed]

I'm interested in ways to automate the generation of DEMs from Sentinel-1 SAR data over a particular region. Is there a way to script the DEM generation, preferably from Python?
1
vote
0answers
25 views

Conversion of EGM96 to NAVD88

I am new to ArcGIS and geoids/ellipsoids, and I want to convert a dataset in EGM96 (the USGS SRTM DEMs) to NAVD88. I have the SRTM dataset from NASA downloaded and open in ArcGIS as .hgt files. I ...
0
votes
1answer
25 views

Looking for data to create contour lines at close range

This is my first post here and I'm new to GIS and I'm not massively even sure what I'm asking, so please be gentle! I'm attempting to learn QGIS through self-study and my idea is to take on a few ...
0
votes
0answers
12 views

Planchon & Darboux depression filling algorithm - Meaning of epsilon

I hope this is the correct place to ask this, but while trying to understand (and implement) the Planchon & Darboux depression filling algorithm, I came across a bit in the pseudo code I do not ...
1
vote
0answers
13 views

DEM from overlap monocular images Pleiades

I am trying to create a DEM from 4 overlap monocular satellite images of different dates from Pleiades using UP42.com. But I could find only information about stereo images processing. Is it even ...
1
vote
0answers
38 views

Removing rectangle line in DEM

enter image description hereI have downloaded Aster dem file. One of my dem file has rectangle line. Does any body know how to remove it? I am using QGIS 3.4.
0
votes
0answers
8 views

Combine depression filling and stream burning in one single step

As we know both depressions filling and stream burning will modify the DEM data. And I learned that sometimes we need fill-burn-fill to make the DEM is ideal for the follow-up steps. So can we merge ...
1
vote
1answer
13 views

Merging two DEM rasters in ArcMap

I tried to merge two DEM-rasters without any overlapping parts using "Mosaic To New Raster" tool. However the value range of output raster doesn't look correct. Assuming that (A1,B1) and (A2,B2) are ...
0
votes
1answer
25 views

Problem with open data ArcGisMapServer from SITG (Geneva) in QGIS

I would like to use this open data DSM data source QGIS from Geneva, Switzerland municipality. Here is the data server I tried to link it as an ArcGisMapServer source or as WMTS. But when I open the ...
1
vote
1answer
68 views

How to extract contours from .jp2 DEM dataset?

This will be a little long-winded but I'm including all information I consider relevant. Problem: I have received a data set from a municipality that is a 3-layer LiDAR JP2 DEM and need to extract ...
0
votes
0answers
17 views

Altitude information for European highways

I need to calculate the gradient in major European highways. Fot this I need altitude data for each highway, let's say every 100 meters. Are there such kind of data publicly available? If not, I am ...
0
votes
1answer
49 views

Convert GOCAD .ts file to a raster for ArcMap Analysis

I have a multi-layered (10 layers) GOCAD .ts file of data that I would like to convert into a series of rasters. The documentation says it requires a program capable of reading GOCAD * .ts (...
0
votes
0answers
41 views

ArcGIS pro Runtime Error: Cannot open shape file through Python Add-In

I am facing runtime error while running this Python script as an extension to ArcGIS Pro version 2.522081 I also checked for minor errors and typos in the script, have gone through the documentation ...
1
vote
0answers
39 views

QGIS create contour from DEM

I have created a DEM from points using the raster interpolation method, the TIN function, based on elevation of each point. However, when I try to create a contourline, the results show the contours ...
0
votes
1answer
69 views

Transfering height information from DEM to line feature to use in profile with ArcGIS Pro?

I am using ArcGIS Pro 2.4. I want to make a height profile of a line segment. The line has no height information, so I want to transfer height information to the line from a dem. How can this be ...
0
votes
0answers
14 views

Calculating slope of numpy array using gdal.DEMProcessing

I am trying to compute the slope of a numpy array using gdal.DEMProcessing. Here is an example of what I am trying. Here in the example I am loading a portion of a DEM file, when I try to compute the ...
0
votes
1answer
20 views

Splitting GEOTiff of Mars

I am trying to make a map of a terraformed Mars in QGIS and as a part of that, I need to convert the Mars MOLA DEM into contour lines at an interval of 100m. However, the file is too big for QGIS to ...
0
votes
0answers
21 views

Flip Road-Lines based on the direction of apparently parallel DrainageLines derived using DEM

I have 2 FeatureClasses one is road lines (Red coloured as shown in the attached image) with random digitized direction and another is drainage lines (Blue Lines) derived using Raster DEM with correct ...
0
votes
0answers
40 views

Elevation obtained from USGS DEM is different from Lidar elevation

For a project I'm working on I need to calculate height of objects for which I know their spatial 2D coordinates (e.g. buildings). I'm using Lidar data to extract the highest Z value for an object, ...
2
votes
1answer
114 views

Is there a tile server for DEM data?

I'm new to GIS and I'm using QGIS 3.4.5. I've been downloading individual SRTM tiles containing DEM data and merging them together in order to see the elevation of every point in a given area (such as ...
6
votes
3answers
379 views

Vertical datum query for coastal modeling

I have a USGS derived DEM with a vertical datum of EGM96 from NASA satellite data. My Bathymetry uses a lowest astronomical tide datum. Has anybody come across this or similar issue before? I need ...
0
votes
1answer
46 views

Getting elevation data from DEM

I'm trying to extract elevation data from a DEM file but I can't make it work. I want to extract contour lines from a given area, and label those lines with the proper elevation value. The problem I'...
0
votes
0answers
34 views

Get catchment area of a lake polygon in R

I have several DEMs as geotiff files which I load into R using raster::raster. Additionally, I have lake outlines (located within the DEMs) in the form of shapefiles which I load into R using raster::...
0
votes
0answers
12 views

ARCGIS-Slope map with different X and Y cell resolution

I have a tif DEM with different resolution in X and Y : cell size x =0.000222222222222222 cell size y=0.000111111111111111 with col=4501 and row =9001. The resulting slope map that I have is a tif ...
0
votes
1answer
35 views

Creating a DEM from PDF?

sorry if this is a simple question, but based on my search terms I keep getting PDF papers about DEMs. Someone has asked me to generate fill quantities off of their lidar data which they have ...
3
votes
1answer
354 views

Python: Convert DEM to 3D array organized as [lat, long, elevation]

I'm trying to convert a .tiff DEM to a numpy array using python. Ideally the array will store latitude, longitude (or some coordinate alternative), elevation). I'm using Gdal but currently it only ...
4
votes
1answer
176 views

Use DEM elevation attributes in vector polygon?

I am modeling glacier retreat scatching polygons on DEM surface trying to come out with 3D scatch. Is it possible to adjust "height" of polygon to follow elevation of DEM surface (eg. glacier height ...
0
votes
0answers
22 views

NASADEM data around 180th meridian

I am following this thread What is NASADEM and when it will be released? and saw post from @markusN and start to download the data in nc format for few analysis in various countries. Recently I tried ...
0
votes
1answer
22 views

How to get elevation value in CSV format in R from raster SRTM DEM file?

I am trying to get elevation value in meter using R programming. I have loaded raster library in rstudio: elevation <- getData("alt", country = "BD") How I can get those value with lat lon? ...
0
votes
0answers
10 views

Modifying existing DSM from new slope raster layer for optimizing solar panel in solar radiation tools

I would like to calculate solar radiation of some building roofs using area solar radiation tools in ArcGIS Pro. However, I need to modify my DSM (input raster) because I want to optimize the panel ...
1
vote
1answer
48 views

How can I 'fill in' the sea in a DTM raster in QGIS

I am using OS Terrain 50 data, mosaicked with R, to make some nice 3D maps using Rayshader. However, for coastal and island areas, there are large gaps where the sea is. How can I easily fill these in ...
0
votes
0answers
24 views

Adding two rasters results in negative infinity and positive infinity

I'm trying to create a hydro-flattened DEM according to USGS specifications. I have two rasters, a DEM of my study area and a raster that only contains the water bodies that I have flattened so the ...
1
vote
0answers
22 views

Create shadow mask from DEM using QGIS

I am looking to create a shadow mask based on a DEM, with the sun conditions (azimuth and altitude) known. I am using QGIS, and had hoped to use the r.sunmask.position tool for this. The DEM is in ...
0
votes
0answers
17 views

Add buildings contours to DGM for hydraulic analysis [duplicate]

I use Hydrology Terrain Analysis Tools in QGIS/ArcGis. Now i try to add some building contours to my DEM. I got building Data (Polygons) and a Raster DEM. Finally i want the buildings added to my DEM, ...
1
vote
1answer
1k 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
1answer
33 views

How can I create GeoTIFFs from OS Terrain 50 data?

I'm playing around with R Rayshade, which creates lovely 3D terrain images using GeiTIFFs. I've been testing it out with SRTM 1 Arc-second images from USGS, but these are quite low resolution. OS ...
0
votes
0answers
20 views

Point to Raster - receiving integer although Points are floating point

I had to adjust a few raster cell values of a DEM, that's why I converted the raster DEM to point shape file and fixed that. Now that I want to generate my DEM again I have the following issue: While ...
0
votes
1answer
53 views

Interpolating DEM using Kriging in R

I have several DEMs as geotiff files which I load into R using raster::raster. Now some of these DEMs contain patches of missing values, represented by NA. I would like to interpolate these missing ...
1
vote
1answer
1k views

Digital Elevation Model resolution [closed]

When I create flood areas using DEM in ArcGIS, which parameters do I consider to determine DEM's pixel size and resolution?
0
votes
2answers
39 views

Guide book of SNAP

I would like to study SNAP Software made by ESA. I don't find any PDF or book online. Have you any ideas where I can find it?

1
2 3 4 5
32