Questions tagged [terrain]

The vertical and horizontal dimension of land surface

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46 views

NA values as result from r.slope.aspect in R

As the result from r.slope.aspect I get a raster with only NA values. r.param.scale works, but doesnt generate dx and dy maps, which I both need for r.sim.water function. Unfortunately I can't ...
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44 views

Using Aspect tool in QGIS

For my bachelor thesis in biology I´m working with QGIS 3.14 (Pi) and tried to create a layer where the slope aspect/expositon/exposure is presented. I´ve got a DTM1 on hands. There is this function ...
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3answers
74 views

Terrain aspect similarity

I have a point data set with terrain aspect at the location of the points, measured in degrees. I want to compute the similarity of aspect between the points, e.g. 70° is similar to 90°. This is ...
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16 views

Lidar Dataset for Toe and Crest Detection

I have read a paper on Terrain Toe and Crest Feature Detection and Labelling forAutonomous Mining and started working on building the code for this. But I am unable to find the dataset used in the ...
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38 views

Extract terrain coordinates as seen from a viewpoint + FoV in a digital globe

Context Every one working with photogrammetry or 3D knows what a depth image is. For example OpenCV defines a "depth map" from a stereo pair, e.g.: where the darker a pixel is, the greater ...
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1answer
44 views

How do you export a 3d-model in QGIS to a file that can be read in Rhino?

I am really new to QGIS and haven't really gotten familiar with all the functions yet. I've made a 3D map/model in QGIS, and would like to export this in a file format so that I can use it as a ...
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1answer
78 views

Earth engine - ee.Terrain.slope() output at wrong resolution after DEM mosaicking

The big picture: I'm using Google Earth Engine (Javascript) to do a terrain correction on Sentinel-1 imagery, as in Andreas Vollrath's work. However, I want to use a higher-resolution Canadian digital ...
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0answers
17 views

Using ArcMap to build a Terrain DEM that looks exactly the same as a TIN built from the same point shapefile

I am attempting to replicate DEMs previously constructed as TINs in the Terrain format. Building a Terrain and a TIN out of the same point shapefile produces two maps that look extremely similar, but ...
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1answer
110 views

Getting from a USGS historical topographic map to a Unity terrain heightmap

Is it possible to start from a USGS historical topographic map and get to a Unity terrain heightmap? To see an example of the kind of historical topo map I am talking about: Go to: https://ngmdb....
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37 views

Define Terrain/Elevation textfile data format

I have a program that can visualize terrain/elevation data but will only recognize files in the below format. It has the extension .map but it is not recognized by QGIS or GDAL so I believe it may be ...
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28 views

How do I “flood” a terrain in Cesium to represent a high water level

I am thinking about using a plane object to represent a water level by rendering it as a certain height above ground using Cesium. Is there any example code that
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1answer
130 views

Creating contour lines from DTM in PostGIS

Is there any possibility to compute contour lines from a raster DTM directly in PostGIS on a PostgreSQL database? I have only found this solution based on points "Fast contour lines using plain ...
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1answer
61 views

What is meaning of scale on x and y axis of image using matplotlib

I am finding elevation of a region using richdem. Can somebody tell me what is the meaning of the scale which is on the x and y axis of the image? import os import numpy as np import matplotlib ...
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52 views

DSM results from WebODM are not correct [closed]

I am new to WebODM and I am trying to generate DSM and Orthomosaic images using default settings in WebODM. The Orthomosaic image is correct by providing GCP but the DSM file is having inaccurate ...
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1answer
112 views

Digital elevation model - getting files in the .DEM extension

Could you tell me from where can I get the Digital Elevation Model data in the .DEM file extension? The option for QGIS here: https://www.qgistutorials.com/en/docs/working_with_terrain.html shows the ...
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1answer
98 views

How accurate are Ordnance Survey MasterMap topography spot heights?

The spot heights in the Ordnance Survey MasterMap sample data over Exeter with feature code 15404 are presented as an integer value in metres. But how accurate are these spot heights? I had assumed ...
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24 views

Problem with weird values in DTM and not showing correct elevation

I am still new to Gis and don't know if I understand what is wrong. I am working in a ocean survey program with point clouds. As seen on the picture the minimum depth is 1,92 and maximum 12,02. I ...
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139 views

Point/Area location of data in reference to geotransform of raster

I'm trying to understand how to interpret the position of pixel data within a GDAL raster, specifically as it applies to files containing height data. I'm create Triangular Regular Network (TRN) for ...
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1answer
44 views

ArcGIS 10.X - DEM raster creation - Point to Raster vs. Terrain to Raster tools [closed]

I have a bunch of LiDAR data that I need to make a raster DEM & DSM from. From what I can gather my options are use the Point to Raster tool directly on the Multipoint feature or make a terrain ...
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2answers
514 views

Profile tool and GPS data in QGIS

I am trying to get elevation graph with the Terrain profile tool on my GPS data and can't get it to work. I have GPX file from a drive. I got this imported in QGIS. I have elevation data for each ...
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1answer
271 views

Cutting/ exporting multiple terrain profiles to CSV files with QGIS?

I am trying to cut multiple terrain profiles and export them to CSVs (individual or combined). I have a shapefile of the profile lines, and a DEM to cut the profiles from. I can do this manually ...
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1answer
417 views

My 3D polygons are being drawn below terrain

I'm importing a JSON file with polygons but I can't put them at the terrain ground level. They insist to be below the terrain. I've created my own terrain server using DEM SRTM and the docker tumgis/...
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1answer
232 views

Creating 3D image from HGT files?

Is there any command line tool to create a 3D terrain from a DEM SRTM HGT file like this? I mean, given a camera position, a HGT file and a satelite image. EDIT 1 First try to adapt mdsumner's ...
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0answers
64 views

VRM tool QGIS error generating layer

I am trying to use the VRM tool in QGIS of the SAGA package. Every time I get an error message: layers could not be generated. I tried different input rasters (DEM and DTM) and kept other settings ...
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1answer
79 views

Aligning shapes to terrain in CityEngine?

I have a problem. As soon as I click "Align shapes to Terrain", my shapefile rectifies and falls down the edge. In the first picture(Border_Issue1) you can see that all shapefiles have the right size,...
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1answer
61 views

Integrating sea level curve data in a bathymetric grid

I am attempting to apply these data recording where sea-level was in the Gulf of Mexico (in meters below mean sea level) over the past 20,000 calendar years at a 500-year resolution in ArcMap: What ...
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1answer
179 views

r.surf.area command of GRASS GIS is giving a very small area

I am a beginner to GIS systems and am trying to calculate the surface area of a dem using r.surf.area command of GRASS GIS. The surface area it is giving me is unacceptable as it is very small. It is ...
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1answer
119 views

Creating DEM raster from ASCII .xyzi LiDAR [duplicate]

I was passed along some LiDAR data that is in .xyzi ASCII format. I am having trouble figuring out a way to build a TIN or DEM from this data. I brought it in using "ASCII 3D to feature", and ...
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1answer
433 views

Converting DEM (TIFF) files to terrain files?

I want to create an app to show 3D using ol-cesium. In ol-cesium example it use cesium terrains, But I want to do it with my DEM files. How can I convert my DEM (TIFF) files to terrain files?
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1answer
105 views

Finding glider reachable area / catchment area with custom slope?

I'd like to produce maps for gliders in mountains. I'm looking to display the reachable area by a glider taking off from a given point (obviously with the corresponding DEM). For a first approach I'...
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1answer
730 views

Using terrain correction in SNAP sentinel 1 toolbox removes all the values

I am new to SAR image processing, I have a SAR sentinel 1 dataset downloaded from ESA site: S1A_IW_GRDH_1SDV_20190314T030905_20190314T030930_026328_02F196_2EC3 I am trying to do terrain correction ...
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1answer
106 views

Nested loop and terrain analysis R

I have a raster stack with 11 layers that I am running through a triply nested lapply(). I expect 44 layers to be returned, but I'm only seeing 4! Reproducible example: # Load packages library(...
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1answer
76 views

City Engine: Align Terrain to Shapes - Purpose?

What is the purpose of aligning the terrain to shapes, if I have already aligned my shapes to the terrain? In my understanding, the terrain is a reference surface, and therefore I wouldn't want to ...
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1answer
762 views

Merging several .hgt files into one

I'm currently struggling on trying to combine several .hgt files with different software. I can get the 4 tiles into any kind of software but my issue is exporting the file back to .hgt file. I've ...
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2answers
802 views

How do I calculate the Terrain Ruggedness Index for each county in the United States in R?

I have a shapefile of US counties and high-resolution elevation data that spans the entire contiguous United States. My goal is to calculate a terrain ruggedness index for each county. The functions (...
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0answers
157 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 ...
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3answers
1k 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 ...
2
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1answer
370 views

Cannot access Terrain Server for Cesium

I'm trying to follow a series of tutorials: visualizing-terrains-with-cesium-ii visualizing-terrains-with-cesium Some other useful posts here: Unable to serve Cesium Terrain files error-in-...
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1answer
443 views

How should I interpret R terrain/slope output in degrees?

I'm calculating the average land gradient (in degrees) in Brazil and I do not know how to interpret the results. As I'm calculating the slope in degrees, 0.25 is 0.25 degrees, 25 degrees or should I ...
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1answer
40 views

Calculating Viewshed of a region rather than a point [closed]

There are various calculations to find the viewshed of a point and all of them have different runtimes. the fastest is the calculation of line of sight angle and compare with upcoming cells. But what ...
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0answers
50 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 ...
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2answers
841 views

“Relief” function from the Raster Terrain Analysis plugin in QGIS 3.0

I am using QGIS 3.0, where I can't find the Raster Terrain Analysis plugin. I am under the impression that the plugin was embedded into the QGIS 3.0 version, as under "Raster --> Analysis" there ...
2
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1answer
173 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 ...
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0answers
92 views

Converting Surface Model to Elevation Model?

Is there a way to convert a digital surface model (DSM) to a digital elevation model (DEM) in QGIS? Surface models contain lots of noise (e.g. trees, buildings) when I only want to show the ground. ...
2
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1answer
678 views

cesium quantized mesh generator

We are trying to develop pur own quantized mesh generator and visualize these terrain tiles on CesiumJS. As an input we use SRTM data that belongs to north parth of TURKEY. We generate contours on DEM,...
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0answers
91 views

Using the height of river to approximate its extreme flood boundaries - terrain analysis in QGIS?

Using QGIS I'm trying to analyse an area/DEM with this criteria: - heights 10 meter above the river-centerline in both sides of river. I can do it with the calculation of contours (2m) from DEM and ...
5
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0answers
375 views

Using QGIS 2.14 to creating a evenly distributed grid of points, spaced 500m apart, that takes terrain into account [closed]

I am using QGIS 2.14 (Essen Version). I need to create a grid of points within a given area so that each points 500m across the ground from any other point. At these points trail cams will be placed,...
2
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2answers
612 views

Clipping terrain in ArcMap?

Is there a way to clip a terrain in ArcMap, or make sure it doesn't exceed a certain geographical extent area in the first place? After creating my terrain from a multipoint file it looks like this: ...
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1answer
898 views

Interpreting results in legend, SAGA GIS or QGIS? [closed]

Can somebody explain to me what units of measurement do I get in the results of analysis, ground morphometry in SAGA GIS software or through a plugin in QGIS? for example: Terrain ruggedness index (...
5
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2answers
1k views

Using slope and total height for terrain analysis in QGIS?

Using QGIS I'm trying to analyse an area/DEM with these two criteria: -Even sloping terrain steeper than 1:20 and total slope height > 5 m. Finding areas with slope of 1:20 (5% slope) could be done ...