Digital Elevation Model (DEM), which could be a Digital Terrain Model (DTM) or a Digital Surface Model (DSM).
1
vote
1answer
82 views
How to remove terracing from Civil3D GeoTIFF export?
I've received a GeoTIFF DEM that was exported from Civil3D and at every contour there is a distinct terrace created when I process an aspect or slope in QGIS with the GRASS plugins.
I've looked ...
3
votes
4answers
404 views
Batch processing DEM rasters in QGIS/GDAL
I am attempting to add relief shading to map using .asc raster files, following this tutorial. It works well, but I have only tried it on single tile of raster data which is 20x20km. I want to ...
1
vote
2answers
248 views
Import Civil 3D DEM to ArcMap or QGIS
I have some survey data exported from Civil 3D in both dtm and dem formats. I thought the I would be able to use the dem more easily, but I think the format is different from a USGS DEM. Is it ...
2
votes
0answers
49 views
Arcpy: Counting number of segments where altitude rises or decreases based on DEM?
I have a DEM of Sudety mountains and linear .shp with several hiking paths.
I'm trying solve one problem: How to make a script based on input DEM and input line shapes that would count number of ...
4
votes
1answer
148 views
Raster DEM generation
I have two shape files containing height information of a certain area and I need to create a raster DEM with GRASS using them.
file 1 consists of height information in contours (isolines)
file 2 ...
3
votes
4answers
441 views
Open source tool to view DTED and DEM raster-data
I am new to GIS field. Is there any open source GIS tool to view DTED and DEM tiff-files?
Update 1
I have some DTED files and DEM files. I want to open and see those files using some open source GIS ...
6
votes
1answer
338 views
How to calculate te area between contour lines on a DEM with Qgis 1.8?
Does anyone know how to calculate the area in km² for each altitudinal band (between 100 and 200, 200 and 300...) based on a DEM? I added the contour lines with a distance of 100 metres but could not ...
2
votes
1answer
166 views
Orthogonal Height Profile along line (sextante -> v.segment, r.profile?)
While trying to find a way to find "valleys/ridges" within a DEM, I'd
like to know if there are tools, plugins or "methods" known or
available to automatically generate height profiles along a given
...
5
votes
1answer
106 views
Calc bottomline of valleys
Which way do I calculate bottomlines of valleys or even more preceise:
which way do I "find" valleys (for example suggested tectonic faults).
Sample below shows a height profile (profile from line) ...
11
votes
3answers
235 views
PostGIS interpolation / triangulation options
I'm looking for an open source workflow to automate DEM construction. We have a series of sites that fall within a LIDAR dataset. We want to create site specific DEM's for each site, and we're ...
3
votes
2answers
304 views
Exporting DEM-derived rasters to CSV from QGIS?
I have been able to import into QGIS a set of raster topographic maps and the associated DEM raster maps. It registered the two for me. From there I have calculated the associated slope raster map. ...
3
votes
1answer
53 views
Is it possible to create DEMs from ORT format in QGIS?
I recently requested DEMs for my area of interest. The data has however arrived in ORT file format - how do I create DEMs from this data in QGIS? When I open the files in Notepad there are three ...
0
votes
0answers
74 views
Digital elevation Model trouble
I've got a DEM with a resolution of 15m covering a small part of the UK. I am trying to use it calculate slope angle in ArcGIS 10.0. However when running the slope tool the problem I'm having is the Z ...
8
votes
5answers
232 views
How to ensure uniform colour for DEMs?
This is a silly question, but one I've been trying to figure out for a while. I have two Aster DEM tiles, one next to the other. How do I ensure uniform colour for both?
3
votes
1answer
120 views
Where can DEM data for all of British Columbia be found?
Is there a website or server from which a DEM covering all of BC can be downloaded - preferably at 1:50K scale?
GeoBase has tiles for 1:50K and 1:250K, but they do not provide it as a mosaic. It's ...
1
vote
2answers
190 views
Can I sell maps produced from ASTER Global DEM V2 data?
I don't quite understand the term-of-use of ASTER Global DEM V2 data:
By selecting 'Submit', I agree to the following:
-I agree to redistribute the ASTER GDEM only to individuals within my ...
4
votes
1answer
208 views
Create DEM from stereo pairs?
Can ArcGIS Desktop (or any of its native extensions) allow me to create DEMs from stereo pairs (acquired by satellite, Geoeye 1)?
If the answer is a clear no, brownie points will go to an answer that ...
2
votes
1answer
151 views
gdal doesn´t support my *xyz file
I have just exported a tif DEM to XYZ format with SAGA GIS. When I check this with gdalinfo it states that the format is unsupported?
Seeing as I converted this with saga gis which used gdal I find ...
1
vote
1answer
239 views
Problem merging two rasters in Qgis
I have two rasters in Geotiff, same CRS. I tried to merge them and I have this error code
ERROR 4: `C:/Anita_Tepoztln/Rasters/e142.tif' does not exist in the file system,
and is not recognised as a ...
1
vote
3answers
383 views
How To find the Catchment Area for a Dam?
I have a DEM of my study area, and polyline shapefile of the Dams in that area.
I have run the standard Hydrology tools on it( Fill, Flow Direction & Flow Accumulation).
I know that you can ...
2
votes
1answer
313 views
How to know if flow accumulation map reflects true catchment areas?
I have calculated flow accumulation (img file) using this DEM (img file), which is 0.5 degree resolution, using arcmap.
I am wondering if the cell accumulation value can directly be translated into ...
1
vote
0answers
22 views
Can I burn stream network into DEM using DEM layer only? [duplicate]
Possible Duplicate:
How to ‘burn’ a stream network into a DEM layer in ArcGIS 10?
I am doing hydrology modelling and I want to calculate the run-off. In order to do that,the model which I ...
5
votes
1answer
105 views
How do I find location of minimum value within a buffer (around a point)
I have a digital elevation model (DEM) with a point location defined.
I want to locate the lowest height values at a set distance from this point.
I envisaged creating a buffer around the point ...
3
votes
3answers
355 views
Merge DEM and Hillshade to create one file?
I am wondering if I could merge DEM and Hillshade ? What is the pro and cons for that? Thanks
5
votes
2answers
229 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 ...
5
votes
2answers
881 views
Is there a way to clip a raster using a vector polygon without having Spatial Analyst?
I have ArcView 10 and I'm trying to clip a DEM (TIFF) to a wilderness boundary (polygon). I know ArcView won't let me do this without Spatial Analyst, but I don't have $2500.
I tried exporting my ...
1
vote
1answer
139 views
arcgis python window VS pywin32
I have problems while using the ZonalHistogram function in Python. It seems to give strange results, while, with the same code run in arcgis' python window everything works fine.
I am trying to study ...
1
vote
1answer
209 views
Where to acquire free elevation data for Thailand/Bangkok?
I am in the process of writing my thesis on flood hazard preparedness and forecasting in South East Asia, specifically Thailand. My analysis requires a medium resolution (even better, high resolution) ...
2
votes
1answer
301 views
Extraction of DEM from netCDF file into ASCII XYZ format
I need to extract a DEM of a waterbody from a netCDF file so I can ultimately convert the DEM into xyz format. I'm not sure how to go about doing this, and so far, I have tried to create raster layers ...
1
vote
1answer
252 views
Using Latitude and Longitude with SRTM3 DEM file
I am new to working with DEM files but have a need to be able to work with SRTM3 DEM files to calculate elevation given a Lat,lon coordinates.
I understand from reading the documentation that the ...
1
vote
2answers
156 views
How do I intersect DEM and a polyline?
I'm working on Qgis, I need the longitudinal section of a river.
Thanks
1
vote
1answer
212 views
How to calculate an hypsographic curve of a raster trhough a DEM
I am using Arcgis 10.1.
I have a MODIS raster from the NSIDC website with a pixel resolution of 500 m and an attribute table with the fields 'VALUE' (as the code of snow, clouds, etc.) and 'COUNT' (as ...
6
votes
3answers
440 views
Generating a TIN from a DEM without ArcGIS
I'd like to generate a 3d terrain model moving from a DEM dataset (currently in shp and GeoTIFF format). As far as I understand it, the first step of the better path would be generating a TIN, but I ...
2
votes
1answer
70 views
Looking for literature on correcting one DEM with another
I am looking for some scientific papers (any language) according how to deal with the correction of one DEM with a other (such as ASTER with SRTM). Any idea? Thanks!
5
votes
2answers
462 views
How to compare two DEMs and show their difference?
I want to compare my DEMs (ASTER GDEM2 and SRTM4.1). I know, that the GDEM has some extreme "holes" with totaly wrong elevations (I found 3 of them in my working area). Now I need to know, if there ...
2
votes
1answer
270 views
How to manage null values in QGIS
I made a merge of several AsterGdem blocks near Egypt and Israel. I have portions of the Dead and Mediterranean Seas. Since near Galilea elevations are below sea level this makes the following problem
...
0
votes
0answers
107 views
Importing Large Raster Datasets in Global Mapper
I'm having issues importing large amounts of data. I have about 25 gigabytes (2752 files ) that im trying to export as one big hill shade. I did this successfully in ArcGIS but i wasn't happy with the ...
2
votes
0answers
136 views
tools from Geospatial Modelling Environment in ArcMap model
How to extract raster DEM elevations to vector attribute tables in ArcGIS 10?
Can GME tools be used in model for publishing a tool on web? I want to use it in integration with other tools in ArcMap.
...
3
votes
1answer
140 views
DEM local adjustments - terraforming
I'm looking for software that can perform local adjustments in DEMs with tools similar to paintbrushes used in graphics editing programs but streamlined to respect geomorphology.
To give you an idea ...
8
votes
1answer
327 views
Floodplain generation given river section polylines, flood level elevation points and a DEM of the land surface
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, given the following datasets:
1) River cross section ...
4
votes
4answers
280 views
Does a value in srtm dem file refer to the center or corner of a cell?
I'm working with srtm dem files. They are ascii text files containing a table/grid of elevation values. At the top of the file is some metadata to locate the grid in lat/lon:
xllcorner ...
3
votes
1answer
401 views
DEM: How to convert a mosaic dataset to TIN?
I merged several DEMs together in on single DEM with mosaic dataset.
Now I wanted to convert this mosaic dataset in Vector with TIN. But when I use the tool (3D Analyst Tool) Raster to TIN comes an ...
2
votes
1answer
280 views
Creating a constant elevation raster with multiple attributes
Is it possible to create a raster with a constant value with multiple attributes? Such as:
rowid value count Name
1 630 36000 Forest
2 630 75000 Anthro
3 630 2600 ...
8
votes
3answers
942 views
Best method to aggregate 1m DEM mosaic to 10m DEM
I have a mosaic of a 1m LiDar derived DEM. I need to output a subset of the data as a 10m DEM. I am currently using the aggregate tool in ARCGIS 10 to produce a mean value for each new 10m pixel. ...
4
votes
2answers
385 views
Best Program to use for DEM data?
I need to estimate the elevation at various access points of some rivers in South Carolina. I use the elevation information to calculate the average gradient (feet/mile) between two access points. The ...
2
votes
4answers
299 views
Is there a way to programatically force RGB (3 bands) in a raster with arcpy?
I'd like to include conversion to a 3 band RGB raster in a script to prepare multiple DEMs for image processing. The input files are rasters extracted from a raster mosaic.
The manual option is to ...
5
votes
3answers
5k views
How to extract raster DEM elevations to vector attribute tables in ArcGIS 10?
I have an ArcMap 10 project with multiple layer groups. One layer is a raster DEM, another layer group is a bunch of vector shapefiles (including points, lines and polygons). The client wants all ...
7
votes
3answers
442 views
Creating raster or vector raster from DEM point file?
i have a point shape of 75.000 elevation points in a regular 5 m grid.
We now want to create a polygon grid with the elevation points as "centroids".
Unfortunately, all attempts to do so fail:
I ...
10
votes
4answers
364 views
Dikes extraction from DEM
I do have DEM of 1x1 meter and original LiDAR point cloud in .las, that DEM is made of. I need to extract river dikes (highest points of the dikes) to vector feature (point, polyline). Any idea for ...
4
votes
4answers
724 views
Definitive source for downloading DEM data
USGS has been moving towards serving data through The National Map Viewer. They have several WMServices through their website that serve elevation data to the public (hillshade & DEM). The ...
