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

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0answers
17 views

EU DEM licensing compared to SRTM and others

Where can I find the actual full license of the EU DEM? That download webpage has a checkbox saying "I am aware that I am downloading non-validated data and I accept to not distribute the information ...
2
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2answers
74 views

Pixelated DSM using LAS Dataset to Raster?

I am using ArcGIS 10.2.2, and I am trying to create a DSM out of some LIDAR data. After checking the LAS Dataset properties, I see that I have an average point spacing of approx 0.3. I tried ...
1
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0answers
15 views

Reproduce a raster with same cell size but different no of columns and rows

I have a DEM raster of 200m resolution, the no of columns and rows are 2458 and 2845, I want to reproduce this raster in a way that the cell size remains the same i.e. 200,200 but the no of columns ...
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0answers
34 views

How to match 2 different rasters?

1st rasters: Satellite image that represents NDVI value [Cell size (5,5) OR resolution :5 meter. Number of rows and columns: 5000, 5000] 2nd rasters: DEM represents heights [cell size (9.0106388, 9....
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0answers
146 views

3D Polyline by Slope on Surface

I wish to project (continue/extend/whatever) a polyline upslope following a specified gradient along a DEM surface. Is there any way of doing this?
1
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1answer
22 views

DEM ASCII for HEC-GeoRAS

I have a hard time understanding what ASCII files are. I have this DEM in asc. I try to import them into ArcMAP 10.3 and they appear in my naked eyes as images however what I found on internet is ...
1
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1answer
69 views

Measuring Volumes using DEMs

I've done quite a bit of research here and elsewhere and am still having trouble coming up with a solution for measuring volumes using a DEM derived from high-resolution (1 m) stereo satellite imagery....
1
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2answers
199 views

Where do I get Elevation Data for Scotland?

So I am new here and I arrived here because I have been searching for quality elevation data for the entire Scotland but I have not succeeded yet. Kindly help if you know where to get the data Raster ...
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3answers
586 views

Downloading free DEM for Scotland, UK?

I need a DEM file for Scotland, UK. Do you know where I can get it from for free? I need to create a watershed for an area of study.
0
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1answer
41 views

Is there a technique to calculate volume using a polygon instead of contour line?

What I'm attempting to do is calculate the volume of a lake using a polygon I created by classifying an image for water. I then extracted the polygon from the classification process. What I'm left ...
1
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0answers
28 views

Flattening topography while retaining structures in QGIS?

I have a set of Terrain data in both DSM and DTM form. What I am trying to do is extract the features (buildings, hedges etc...) that have been removed from the DTM, but I don't want the topography. ...
2
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1answer
32 views

What is NOS Hydrograph sounding data?

How can sounding data be used for bathymetry when depth is positive? I have downloaded DEM (digital elevation model) as shown in the image below but need bathymetry data for H. All I have found for H ...
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0answers
11 views

Resampling using gdalwarp gives me no data

I have an image with the following information. Driver: GTiff/GeoTIFF Files:test_DEM.tiff Size is 91, 73 Coordinate System is: GEOGCS["WGS 84", DATUM["WGS_1984", ...
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0answers
40 views

Extract from DEM base on range of values in ArcGIS or QGIS

I have a very large 0.5-meter DEM and would like to extract a specific region of elevation values... e.g. I've tried creating a contour map but that was taking way too long- >24 hours.
2
votes
1answer
48 views

Failed DEM via Natural Neighbor in QGIS 2.14.2-Essen

Following the indications of Monde Geospatial (https://www.youtube.com/watch?v=bLbY3iMBW-A) I created a CSV file with the altitudinal data (Google Earth) for 2182 total points and imported it into ...
19
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3answers
5k views

How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
5
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2answers
93 views

Improve DTM under forested areas without smoothing?

I'm using a DTM retrieved from LiDAR data and I noticed that forested areas are grainy or not defined. The DTM data was retrieved from geostore.com. Here is one example: Is there any way to ...
1
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1answer
25 views

How to use HGT files in MapInfo

I have a SRTM-3 file and I want to use it to make a DEM of the related world region. I'm using MapInfo Professionale V8 and I'm fairly new to that software, so if there is any tutorial that shows how ...
7
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4answers
299 views

Extracting Values to Points without ArcGIS Spatial Analyst?

I have a raster DEM & multiple points. I want to determine the DEM elevation at each point. Other than manually examining the DEM at each point, (very time consuming with lots of points) is ...
1
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1answer
50 views

Converting resolution to meter using ArcGIS for Desktop?

I have data in the following format: Projection: Latitude-Longitude | | N: 46:08:44N S: 45:54:50.666667N Res: 0:00:00.333333 | | ...
0
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0answers
26 views

Aligned shapes to DTM - CityEngine

I have an issue with the road and parcel layers aligned to DTM in CityEngine. As the following image shows, there several changes in the height in some parts of the model because of the DTM. I have ...
0
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2answers
53 views

How can I work with large DEM in GIS?

I have a very large DEM (about 115Gb). I cannot work with it on my computer. I need to clip a river catchment from this DEM. I work in GIS. How can I do this?
1
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1answer
55 views

How to select lines affected by sea level rise?

I'm doing a part for my master's thesis where I'm trying to find out which sites located near the coasts of Sweden that will be affected by sea level rise. I got a DEM with height data and have to ...
1
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2answers
47 views

Making raster DEM from irregular points shapefile in QGIS?

I assume that first I need to interpolate and then somehow turn it into raster in QGIS?
1
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1answer
47 views

How to convert bathymetry sounding data to DEM (digital elevation model)?

https://www.ngdc.noaa.gov/docucomp/page?url=http://surveys.ngdc.noaa.gov/mgg/NOS/hsmdb/H04001-H06000/H05455_hsmdb.xml&view=hydro/survey&header=none I downloaded the bathymetry sounding data ...
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7answers
83k views

What is the difference between DEM, DSM and DTM?

I am listing some of the acronyms used in our work and had to stop to think about whether to list these together or separately: DEM: Digital Elevation Model DSM: Digital Surface Model DTM: Digital ...
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1answer
1k views

Removing negative values from DEM using ArcGIS for Desktop?

i'm using (ArcGIS 10.1) and i want to remove a negative values from DTM in order to keep just a ground topographic surface.
2
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1answer
44 views

Reverse colour-ramped DEM to its original elevation value?

A have a GeoTIFF LIDAR image which display DEM in its color-ramp version (color relief) from blue (minimum value) to red (maximum value) and green (in between). I don't have the original elevation ...
0
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0answers
23 views

Getting latitude and longitude in decimal degrees from DEM-raster in UTM

I have a digital elevation model (details: ~4300 cols x 3600 rows, cell size 10 m x 10 m, tiff format, projection: WGS1984 UTM, false_easting: 500000, false_northing:0). I would like to have 2 ...
2
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1answer
80 views

Calculating total area overlapping specific raster DEM color interval whose boundaries are confined by another vector?

I know this sounds quite difficult, but maybe it isn't for you or at least it shouldn't if I explain it correctly. (I'm using QGIS 2.14) I'd like to know to calculate total area overlapping a ...
6
votes
1answer
208 views

In hydrologic terrain analysis is there a difference between “pits”, “depressions”, and “sinks”?

In hydrologic terrain analysis is there a difference between "pits" and "depressions"? For instance, Planchon and Darboux (2002) state The usual numerical methods for removing the depressions of ...
5
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2answers
102 views

DEM out of a shaded relief LiDAR?

I have a DEM built from LiDAR data and the file extension is .tif. When I open this file in ArcMap it seems to be a shaded relief DEM (see the screenshot below). It happens I want to visualize the ...
2
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2answers
68 views

Topography data to elevation raster

In a previous question (convert-xyz-points-to-topography-and-calculate-mean-slope), I asked how to interpolate point elevation data to a raster in order to measure slope. Thus I use the Raster > ...
0
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1answer
101 views

How do I convert a DEM GeoTIFF to Contour Shapefile

I have a digital elevation model as a GeoTIFF and I'm looking to generate a Shapefile of contours with 5m bands on the command line. Is this possible? Ideally using GDAL and Python.
1
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1answer
26 views

CRS and Spatial join problem

I try to match two layers. First one is point-type with cities in Europe. Second one is grid layer (polygon) with elevation value. What I want to achieve is to to join the "Z" value from grid layer to ...
4
votes
1answer
74 views

30m/10m/1m resolution DEM for microtopography research

I am conducting research in a region of Illinois that does not have a LiDAR dataset. I am looking to develop a fine scale habitat species distribution model; however, the coarse data available (30m/...
2
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2answers
152 views

Where is the nviz tool in qgis 2.14 with GRASS 7.0.3?

I hope Im not blind but I looked in the grass tools (modules) and qgis plugins but couldnt find it. When i try to run nviz from GRASS the whole programme chrashes just before concluding. Its a ...
3
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2answers
105 views

How to calculate the relative share of an area of a circle that has a slope >15% in Germany

I need to calculate the share of buildable land for the 15 major german cities within a 50 kilometer radius of the city center. Part 1 of the definition buildable is that the area must have a slope &...
15
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10answers
32k views

Converting XYZ files (with regularly spaced xy) to ESRI GRID format?

Normally consultants (LiDAR survey) provide me with data to my specifications; already in ESRI GRID or ASCII GRID format. This way LiDAR data can be easily used with ArcGIS. This time I only have xyz ...
7
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3answers
572 views

Is there a difference between the Planchon & Darboux and Wang and Liu depression filling algorithms? Other than speed?

Can anyone tell me, based on actual analytical experience, if there is a difference between these two depression filling algorithms, other than the speed at which they process and fill depressions (...
1
vote
1answer
56 views

Add DEM layer to Leaflet

I want to add a digital elevation model (DEM) layer to my leaflet map and access the height data through javascript, i.e. I cannot use .png files or qgis2webplugin but rather .tif or some compressed ...
2
votes
1answer
33 views

Applying base heights to raster is giving me different results

I have applied the DEM's base heights to both the raster image, the raster DEM, and a vector file. The DEM and vector file match up but the satellite image does not match up at all. Any suggestions ...
4
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2answers
145 views

Faster way to calculate slope between two points on DEM using ArcGIS for Desktop?

I'm a forester, and I do lots of work with LiDAR derived DEM's. I'm looking for a quick-and-easy tool to calculate the slope between two points. The application for this would be drawing a proposed ...
1
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0answers
23 views

“Select a tool” error Saga: Accumulated cost (isotropic)

I'm trying to run Saga's accumulated cost operation in QGIS on a DEM and set of raster destination points, but keep receiving an "Error: select a tool" in the log after a failed run. There are no ...
0
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0answers
22 views

QGIS asc to GeoTIFF error: “File short, can't read line 3687”

I tried to convert an asc file to GeoTIFF and I had the following error: ERROR 3: File short, can't read line 3687. ERROR 1: (..:)/mdt.asc, band 1: IReadBlock failed at X offset 0, Y offset 3687 ...
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0answers
25 views

Applying values to highest terminal segments in channel network using PostgreSQL?

I extracted a channel network from a dem but due to some technical difficulties the layer had some discontinuities. So after filling them, i suddenly realised that the Strahler orders it gave me were ...
1
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0answers
34 views

QGIS: How to create a crosstab using SAGA toolbox cross calssification and tabulation?

I am trying to use Cross classification and tabulation SAGA toolbox. I have a raster DEM file (14 classes) and raster file precipitation (13 classes). I want to do cross-tab - but I don't know how ...
2
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0answers
52 views

Draw raster on top of a Leaflet map

I want to implement a raster layer on top of a Leaflet map that includes the following functionalities: Digital Elevation Model (DEM) terrain height included in each raster cell GPS-Track (I use ...
1
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1answer
66 views

Raster calculator fails with large raster in QGIS

I'm working in QGIS 2.14.1 with a DEM ranging from 200 feet to 1600 feet elevation called "dem_3m_Zft1b" (geotiff, 16822 X 33349 cells, No-data =-9999) If I enter "dem_3m_Zft1b" > 0 in the ...