The Shuttle Radar Topography Mission (SRTM) obtained elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth. SRTM consisted of a specially modified radar system that flew onboard the Space Shuttle Endeavour during an 11-day mission ...

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23 views

Converting DEM data to height information in meters using QGIS?

I'm relatively new with QGIS and currently I'm working with ASTER and SRTM DEMs. The goal is to create vector heightcontours with labeling in meter. Can you tell me how I can convert the grayband ...
0
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0answers
69 views

How to import SRTM data for the whole planet into TileMill

I need to get SRTM elevation data for the whole planet into TileMill. I already walked through the instructions on Steve Bennett's blog and it worked fine for small areas. The problem is now that for ...
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1answer
91 views

cut square from geotiff

i want to make a 3d modell out of the mount everest and some other mountains. what i need therefore is a 14km² square around the peak from the mountain. so basically i use qgis to extract the area ...
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1answer
54 views

gdalbuildvrt error when mosaicking SRTM data with different NoData values

I'm attempting to mosaic together 9 SRTM tiles downloaded from CGIAR to produce a DEM of Borneo. I'm using: gdalbuildvrt Borneo.vrt BorneoSRTM/*.tif where BorneoSRTM contains the 9 tif files to be ...
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1answer
50 views

How to determine stream elevation points from SRTM raster with stream lines vector?

I should determine elevation points of some streams. I have SRTM raster and stream vectors. Which tools can solve this problem in ArcGIS 9.3? Anybody can write me a workflow how to do this task? ...
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2answers
100 views

Why are poles missing from GIS topographic data?

Why are poles data missing from most topographic resources ? Data from 60⁰ to 90⁰ lat frequently missing from topographic GIS data. Example with SRTM4.1: Common sense or deduction lead me to think ...
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2answers
136 views

How do you convert SRTM HGT elevations from WGS84 into meters above sea level?

I am building a JavaScript script that reads binary HGT files - as generated by the SRTM - and converts the data into bitmaps viewable in your browser. You can try out the script and view the source ...
6
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5answers
313 views

Looking for (nearly) worldwide elevation data

I know the raw ASTER and SRTM datasets. Is there any error corrected version available? Or did anybody already combine the data? At least the ASTER data often misses tiles for costal regions (if there ...
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0answers
113 views

How to best intersect vector data with raster data?

I have Open Street Map [OSM] data imported so that I can access the geometry of buildings. I have also loaded SRTM digital height data from NASA from a GeoTIFF raster. I have projected the raster into ...
2
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1answer
55 views

How to remove/disable last row/column of SRTM GeoTIFF in QGIS?

I've started using QGIS yesterday, and one of my main reasons to use it is to apply colormapped SRTM v4 over Google aerial imagery. Everything is working fine, except that SRTM v4 elevation tiles ...
0
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1answer
86 views

Importing SRTM Data into Grass

I am having issues importing an SRTM HGT file into Grass. I first made a new location as the instructions from this Grass Newsletter Tutorial states. I then went to the download site and downloaded ...
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vote
1answer
71 views

How to: script convertion from SRTM to 3D printable file?

Given a STRM3.tiff file as input. How to convert this STRM.tiff file into a 3D printable file ? which I may load into most 3D printers' sofwares. My objective is to print some terran, lunar, or ...
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3answers
173 views

SRTM NASA hillshade grainy appearance

I'm trying to create a hillshade surface from SRTM files downloaded form Earth Explorer, but the appearance is not the expected. It has a grainy surface that I would like eliminate to have a ...
1
vote
1answer
114 views

How to compare accuracy of two DEM using GRASS

How do I compare accuracy of two DEM data (lidar and srtm) (possibly through rmse) using GRASS GIS? thanks
1
vote
1answer
118 views

How to distinguish SRTM from DTED using C#?

Does anyone know how to easily distinguish between SRTM vs DTED programmatically without opening file metadata header? both are .dt1 or .dt2 extensions.
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0answers
92 views

Efficient computation of path profile with Numpy and GDAL

I have numpy array with SRTM elevation data and I need calculate path profiles - vectors with elevation data from one point (transmitter) to every points of my map. Here's my current solution: def ...
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2answers
414 views

Why is this SRTM TIFF not visible in GRASS GIS 6.4.3?

I want to use interpolated SRTM data for Germany to generate an STL terrain map for use in a CFD application. My SRTM data comes from the OpenDEM project. SRTM data normally has voids, but this data ...
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2answers
166 views

Where can I programmatically download SRTM_V4.1 data?

SRTM v4 is an effort by the folks at CIAT-CSI to scrub, polish, and remove gaps in the raw SRTM data released by NASA (SRTM 3). One userfriendly interface : http://dwtkns.com/srtm/ provides ...
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1answer
125 views

Gdal_polygonize: How to filter pixels above a given value (elevation)?

Given a topographic GIS raster of one country: Given an elevation threshold n = 50 (meters) How to polygonize pixels when z >= n ? gdal_polygonize.py is not clear on this point. It states This ...
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0answers
117 views

What is most suitable DEM to delineate watershed (from spot height, ASTER and SRTM)?

I have three DEMs of our country which are spot height DEM, SRTM DEM and ASTER DEM. SRTM has 90m resolution and ASTER has 30m resolution. My supervisor told me to delineate watershed using these ...
4
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1answer
111 views

Weird raster visualisation

Using the hillshade tool (Arcmap 10) on a 30m SRTM raster downloaded from NED the result is the one in the picture. Why are there those crossed lines all over the raster? How could I remove them? ...
3
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1answer
447 views

What is difference between GeoTIFF and Esri ASCII grid file formats for SRTM data?

what is the difference between the ArcInfo ASCII format and the geotiff file format when downloading the SRTM data. I downloaded the tiles (21) for the Tibetan Plateau and imported thme into ArcMap ...
3
votes
2answers
230 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 ...
2
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1answer
327 views

Conversion from CGIAR GEOTIFFs to SRTM3 like HGTs

Im writing a C program for querying height information from SRTM data. Since reading directly GeoTIFF format is tough job, I decided to load HGT format, which serves great for the purpose. Since ...
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2answers
1k views

How to use SRTM DEM files for shaded relief in ArcMap?

I would like to create a nice shaded relief for France using SRTM3 data. Most of the threads on the subject are from awhile ago, when ArcMap was not able to import these without changing the file ...
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0answers
107 views

How to convert DTED Level 1 into SRTM DTED

We have a GIS tool that handles only SRTM DTED level 1 terrain files. SRTM level 1 terrain files are limited to 60 deg lat. So I need to fill up the gap from 60 lat up to 90 deg lat. I have DTED ...
4
votes
3answers
6k views

How to extract elevation from .HGT file?

I want to asign a specific long/lat position on a map the elevation from SRTM3 data files, but have no idea how to find the specific value. So I want some example of how I can find in N50E14.hgt ...
2
votes
1answer
412 views

Is it possible to produce a decent looking shaded-relief map at 50K-scale-or-larger using SRTM3 DEM?

I'm trying to make a decent-looking shaded-relief map of a particular area in 50K-scale-or-larger using open-source tools. The best (and free) option I have for DEM data for that area right now is the ...
4
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0answers
329 views

How to read Geotiff tags and pixel per pixel values using GDAL C#

I'm new here and I'm new at programing with GDAL C#. My question is how I can get the value of SRTM GEOTIFF pixel to compare with it's neighbors, and how can I get the values of Geotiff tags.
1
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1answer
387 views

Using SRTM data, how to get the coordinates of the peaks visible from a location?

Using SRTM data and a coordinate-altitude database of the peaks, I want to get the coordinates of the visible peaks from my location. I want to make an application similar to this. How is this ...
1
vote
1answer
194 views

How can I recalculate an attribute based on overlap with another layer?

I have 2 layers: The first one is a point Layer (converted from SRTM) with height information. The second one is a polygon layer (shows the forest). I want to reduce the height value - let's say ...
4
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0answers
198 views

How to stop gdalwarp creating world-spanning outputs near the dateline?

I'm using gdalwarp to manipulate SRTM tiles near the the dateline (i.e. 180°, aka the antimeridian). SRTM tiles have a very slight (1/2 pixel) overlap with the meridian. You can see this using ...
1
vote
1answer
444 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 ...
4
votes
4answers
664 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
504 views

Correct ASTER with SRTM or Topographic Map

I have a problem with my DEM again. I decided to use ASTER GDEM2 (for different reasons). ASTER GDEM2 have its problems, I know, and I dont want to discuss that again. I have to use it, because SRTM ...
3
votes
1answer
636 views

Export SRTM30 Dem file as 3d

i have downloaded some SRTM Dem files here: http://dds.cr.usgs.gov/srtm/version2_1/SRTM30//srtm30 They are from the USGS site. I would like to export them as 3d. I have ran through a few ...
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3answers
1k views

How to use SRTM30 Plus data with QGIS or other GIS tool?

I am trying to access the new Bathymetry data published here: http://topex.ucsd.edu/WWW_html/srtm30_plus.html Is there a way QGIS or similar tool can read these files. Nothing seems to be working, ...
0
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1answer
2k views

How can I convert SRTM data to DEM or DTED?

i am working on a project which is not commercial and i need some digital elevation data for visualization. in net i have found a link and i have downloaded .asc data from following link.. SRTM Data ...
4
votes
1answer
1k views

How to read GeoTIFF using PHP?

My current pet project involves creating a web service that uses the CGIAR SRTM worldwide elevation data set. Each request to the service will query for elevation data from a small geographic area. ...
12
votes
5answers
5k views

How to get an elevation profile for a gps track?

I'd like to get a reasonably accurate elevation profile for a track recorded with a GPS (which often has very unreliable altitude data and occasionally none at all, depending on the model.) Does ...
2
votes
2answers
2k views

Converting ASCII grid/NTF to SRTM/DEM

I want to use the Ordnance Survey Land-Form Panorama product in some software called Maperitive, which can read custom SRTM DEM files. The data is provided in the following formats: DXF [Contours] ...
6
votes
3answers
5k views

How to use SRTM Global DEM for Slope calculation?

I have downloaded SRTM GDEM (~90 km resolution). I am using ArcGIS 10. I have tried to use spatial analyst to compute for slope. However, I can not compute for the slope. The output values has only ...
16
votes
7answers
5k 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 ...
0
votes
1answer
377 views

How to transform a DEM to a cartesian coordinate system?

I am using the script r.inund.fluv. I run the script with all the required parameters and it produced a lot or errors. I emailed the author of the script and he said that "I think you are not ...
3
votes
2answers
188 views

How to make the arrows in d.rast.arrow GRASS script visible?

I'm trying to create a Flow or directional raster map (with arrows) from an SRTM elevation map that I downloaded from CGIAR. I already created an aspectMap to be used for the d.rast.arrow. I used ...
4
votes
3answers
719 views

How to get the elevation of the areas in a raster file from SRTM?

I have an SRTM elevation map. How do I get the elevation of each point in the map? I am using GRASS. Is there a GRASS script to do such?
2
votes
2answers
550 views

How to query data from a vector map (shapefile)?

We want to obtain the specific place of the boundaries of a shapefile. We want to be able to get the points of each polygon corresponding to a specific place in order to use these data in an ...
9
votes
4answers
4k views

Downloading SRTM data

Is there an easy way to mass download SRTM data? The data is published for download here, but it's sliced into thousands of small files, and I don't see an FTP option for more efficient ...
3
votes
1answer
484 views

Where can I find USGS SRTM 3 index grid or what procedure should I employ to select tiles?

I would like to download all USGS SRTM 3 tiles for Ontario, Canada from the USGS site: http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/North_America/ Where can I obtain the index that will assist me in ...