The vertical and horizontal dimension of land surface

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3
votes
0answers
526 views

Creating one DEM from multiple ASC files

I am struggling with this several days and now its time to ask how to do it in QGIS. I have very detailed 27 ASC grid files with overall size of 9 GB created from 1m contours of large area (600 m2). ...
2
votes
1answer
111 views

Query DEM Elevation at Point in QGIS

I'd like to be able to pull up a DEM (or create a mosaic of them) and simply query the elevation at points I click. Is this possible using QGIS?
0
votes
1answer
731 views

3D Analyst Line of Sight: what am I doing wrong?

As a relatively new user to GIS trying out 3D Analyst tools, I'm trying to run a Line of Sight which is not working the way I'd expect. Note I'm running the tool straight from the toolbox, no python ...
1
vote
1answer
127 views

Wireframe display of terrain in ArcGlobe?

I have successfully imported a terrain dataset into ArcGlobe which provides elevation values to the globe surface. Is there an easy way I can now change the symbology/display of the terrain/globe ...
0
votes
1answer
299 views

Why do I get these bands on my Height/Dem/Raster

I can't seem to get rid of them, and I've no idea (ok scrap that, I have a vauge idea) whats causing them. First an apology, yes this is quite a large pic apologies, but here goes: How to ...
7
votes
1answer
1k views

Bringing GIS data into Minecraft

A little off the beaten path...: Denmark has built a 1m:1block Minecraft World using real GIS data. Here's the home page, in Danish: http://gst.dk/emner/frie-data/minecraft/, and an ArsTechnica ...
5
votes
1answer
352 views

Generating a vector contour map of fictional terrain

Originally I had asked this on the Graphics Design SE but after some realization of the question I was asking, it's probably better to ask it here. I'm making a fantasy world map in illustrator that ...
2
votes
0answers
119 views

How to optimize color ramp for terrain

I'm working on a project to highlight LiDAR terrain on the web and part of the idea is to show the detail of the data at large scales. I've already read through the excellent Mapbox guide and I've got ...
2
votes
2answers
270 views

Terrain Accessibility map using GIS (ArcGIS or QGIS)

I need to make an accessibility map showing the walking distance based on the terrain and availability of road networks, could anyone point me in the right direction where i could learn to do so. ...
4
votes
1answer
1k views

How to create contours from smoothed DEM instead of using Terrain to Raster?

I'm fairly new to working with lidar and have been assigned the task of creating 2ft contours for the entire county using USGS-provided lidar tiles. Is there a significant difference in the accuracy ...
1
vote
1answer
1k views

Google Earth import terrain

Today, Google Earth allows you to import images to overlay on existing terrain. Is it possible to import custom terrain to replace default terrain in Google Earth? There doesn't appear to be any ...
0
votes
1answer
121 views

How to obtain buildings base (Ground) Height from Esri Terrain Dataset?

How can I join Height data (surface, DTM) from terrain dataset to buildings polygons ?
3
votes
2answers
1k views

Is it possible to give 2d contours a Z-height from their attribute table in QGIS? (Or ArcGIS?)

I have a contour data file downloaded from UK Ordnance Survey, which gives 2d contours of an area in gml format (also supplied in .shp format) with the heights of each contour attached to the ...
3
votes
2answers
923 views

Using ArcScripts

I use ArcGIS 10 I want to use an arcscript to compute an index of ruggedness for each cell of my map. For this purpose, I found, Evan's TRI.aml script here: ...
3
votes
1answer
164 views

Can 2D polygon be used as hard breakline for terrain in ArcGIS Desktop?

I've been working with TINs for years and have only ever been satisfied when using 3D polylines for breaklines. I am currently transitioning to using terrains and after reading the documentation in ...
3
votes
2answers
350 views

Hillshade for 30m NED at continental scale

I'm new to terrain analysis. I have a 30m NED DEM (.tif) for the conterminous US. I would like to generate a nice looking hillshade for the US, but it looks bad - as in pixelated and rough (See ...
0
votes
1answer
157 views

Correlation and terrain databases [duplicate]

I would like to know what kind of computation I could perform on a terrain database. I'm making terrain for VBS2 from raw data (shp files and DTM Elevation files) and then I'd like to be able to check ...
1
vote
1answer
315 views

ArcPy error: Add Feature Class to Terrain. [closed]

I'm writing a script to convert lidar data (in .las format) into a terrain without going through all the clicking and so I can send it out to neighboring states with similar programs (I'm using ArcGIS ...
3
votes
1answer
401 views

Hydro-Enforced/surface constraint DEM Creation using GRASS/QGIS

I am wondering if there is a way to create a hydro-breakline enforced DEM by means of any open source solution? I am able to create a DEM from Lidar data using GRASS, but would like to enforce some ...
1
vote
1answer
256 views

calculating terrain elevation line

I found too many hits on the web to even see the right direction to go. I have to provide a small proxy server serving requests for a line of terrain elevation data between two coordinates. It is a ...
2
votes
1answer
5k views

Can Compound Topographic Index (CTI) / Topographic Wetness Index (TWI) produce negative values?

I am calculating Topographic Wetness Index for a study area using SRTM DEM (90 and 30m). I've seen several versions of TWI (CTI). I have been using: TWI = ln(As +1 / tanB) where As = ...
6
votes
3answers
2k views

Where I can find world terrain data?

I need free terrain data for the whole world which I can import into TileMill. Is there some source where I can download them? Thank you.
1
vote
1answer
78 views

How to conflate terrain data?

I have an 8 km by 8 km raster of 20 m/pixel terrain data. The georeference data has been lost. All I know is that it's within 100 km of Smithers, BC. I realize that this might involve some very heavy ...
1
vote
0answers
32 views

Styling a raster on relief shading analysis [duplicate]

Possible Duplicate: How to create a style file for QGIS from a plain text file? I have a text file which contains the following data eleva R G B 0 153 255 153 100 179 255 ...
23
votes
4answers
4k views

How to calculate terrain Curvature?

I have an elevation raster and I would like to get some basic terrain variables, such as slope, ruggedness, aspect or curvature. The problem is that I don't seem to have the possibility to calculate ...
6
votes
2answers
630 views

Problem Visualizing 3D Terrain Model - USGS DEM

I recently downloaded a GeoTIFF 1 arc second from the USGS National Map Viewer. I added the raster to ArcScene and attempted to visualize the data in 3D. I set the Base Height to Floating on a ...
8
votes
2answers
2k views

Floodplain generation given river section polylines, flood level elevation points and a DEM of the land surface [closed]

I am looking to generate flood plain polygons to represent 20 and 100 year flood zones, in the most accurate and efficient way possible, given the following datasets: 1) River cross section polylines ...
5
votes
1answer
214 views

Cartographic technique for detailing a 'Focus Area'

I'm working on updating a planning document. Whoever was in charge of cartography last time around used a great technique to identify and showcase focus areas (where to focus money and effort for ...
1
vote
3answers
203 views

Terrain Beautification

The satellite imagery i am rendering is not realistic does not look good. So i was planning to improve things through code(like adding noise to data or using different overlay texture for different ...
6
votes
1answer
9k views

Which is better, DEM or Triangles (TIN/Terrain)

Which is better DEM or TIN? What are the benefits/negatives of each?
1
vote
1answer
563 views

How to create a profile with profile points at discrete altitude intervalls, e.g. each 10 m

In both SAGA and QGIS theres a profile-from-line-function that does a nice job of creating profiles. But there's no way to control the altitude spacing. Any ideas for workflows that would allow me ...
20
votes
8answers
2k views

How to generate a random but believable digital elevation model?

Is there a way to generate a DEM, programatically or otherwise (arcpy or R?), that will feed into ArcGIS for further spatial analysis? Perhaps this needs to be broken down into smaller incremental ...
9
votes
2answers
1k views

TRI, TPI, or Roughness

I am working on a site selection projection where I will be unable to perform any in situ observations. A key component of the selection process is the ruggedness of the underlying terrain. I plan ...
3
votes
4answers
5k views

Can I convert ESRI Grid (DEM) raster to USGS DEM?

There is a tool for DEM to Raster in ArcGIS but I need to convert my ArcGIS DEM rasters (mostly LiDAR) into USGS DEM. The idea is to import this DEM into Sketchup and create a "sandbox" TIN surface ...
17
votes
5answers
4k views

Given a terrain, how to draw the stream flow path?

Assuming I have a terrain, as usual the terrain has ridges, creeks and all the characteristics that you can find on a real life map. Water flows from the top of the mountain into lower area, the path ...
6
votes
3answers
2k views

Finding elevation differences between adjacent pixels in ArcGIS Desktop?

Is there a way to determine what the difference in elevation is between two adjacent pixels? I am using an SRTM DEM to map faults. I am using the vertical error (>16m) as a criterion for the ...
18
votes
7answers
7k views

Are there open access terrain tiles with a permissive license like OSM?

Are there open access terrain pyramidal map tiles with a permissive usage license like OpenStreetMap's? I'm building aviation-related maps with Polymaps and need a good raster basemap. The Google ...
6
votes
2answers
352 views

Auto Balancing in EarthWork

I am not sure whether this question belongs here. I think it belongs more to Geo-technical, but anyway, I just give it a shot. During earthwork development, earth terrain has to be cut ( if the ...
3
votes
2answers
339 views

Where I can find real world data for triangulation?

I want points for practicing triangulation algorithms. Just points with coordinates [X,Y] and elevation [Z] of real world terrain. I can use Google Maps Elevation API, but there is no method how to ...
0
votes
0answers
676 views

buildings shadow areas calculation

is it possible to calculate shadow areas of buildings or simulate shadows of buildings in a city using e-cognition software, with the DSM of the buildings and the sun angle and azimuth known?....if ...
4
votes
6answers
3k views

shadow simulation from buildings [duplicate]

is it possible to use hillshade function in ArcMap to calculate shadow areas of buildings or simulate shadows of buildings, using DSM of the buildings and the sun angle and azimuth?
9
votes
5answers
26k views

Creating profile cross-sections in ArcGIS Desktop?

Because the default 'Profile Graph' tool was not sufficient, I wrote a custom VBA script that creates scaled and exaggerated profile cross-sections in ArcGIS but I need more features: Visualize more ...
2
votes
1answer
145 views

What is a “CFG” application in GIS terminology probably?

I come across a 2008 tech presentation PDF on "GIS-Enabled Modeling and Simulation (GEMS) presented by ESRI (i think for the US Army). On one of the page titled "Challenges to be overcomed", there is ...
7
votes
4answers
561 views

Which ArcGIS product gives full 3D terrain navigation and (flight) simulation?

I looked at the ArcGIS ESRI website and find that 100% of the screenshots depicts a 2D map with at most relief shading. Is there any product ArcGIS or not that gives real 3D terrain visualisation ...
6
votes
2answers
1k views

Has (ESRI) TIN been superseded by Terrain Dataset?

I've had version 10 for a few months but it wasn't until today that I really tested the 3D Analyst extension. (Other then visualizing data) I already noticed a lot of changes; a number of tools have ...
9
votes
6answers
1k views

seeking “Available Sky” implementations

I'm looking for implementations of an algorithm called "Available Sky". ArcGIS (Spatial Analyst or GRID) is preferred, but solutions in GDAL, SAGA GIS or others are perfectly acceptable. The ...