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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2
votes
1answer
29 views

Hillshade result after mosaicing multiple rasters appears irregular

I am trying to mosaic 19 rasters which i already reprojected in WGS 1984 World Mercator and then hillshading them. These are the steps i follow please correct me if i am doing something wrong. I ...
0
votes
0answers
14 views

Which points in projected raster corresponds to certain latitude,longitude location?

What I have is a SRTM 3 arc-second raster file in WGS84 geographic coordinate system (here is that file). I then project it to the Azimuthal Equidistant projection with GDAL: gdalwarp -s_srs ...
1
vote
0answers
23 views

SRTM 30m hillshade output low resolution

I am trying to hillshade 30m SRTM geotiff. The result is terrible. I know that these rasters normally come with geographical coordinates and i have to reproject it before i apply hillshade because ...
2
votes
1answer
45 views

Why do “stripes” appear on raster?

I am reprojecting a SRTM 3 arc-second raster file from WGS84 geographic coordinate system, to projected coordinate system which is using Azimuthal Equidistant projection: gdalwarp -s_srs EPSG:4326 ...
0
votes
0answers
31 views

SRTM data to 7.5 min DEM or 1-deg DEM

I have an issue. I have SRTM data from here (http://www.webgis.com/srtm3.html) which is approximately 90 m / 3 arc-second. I want to convert it to 7.5' DEM or 1-deg DEM. Is it possible? Or is there ...
1
vote
0answers
19 views

Ideal minimal area for watershed automatic delineation using DEM SRTM

I need to do a bunch of analysis on a city using for that, watersheds . As smaller the watersheds are, better are quality of my work. Due to the vertical accuracy of SRTM DEM, I know there are some ...
1
vote
0answers
49 views

How get latitude, longitude and altitude from SRTM SWBD and .hgt files in one table

I know this question may seem repetitive but I am not able find a solution hence I am asking this question . 1)I have downloaded OSDM data, SRTM SWBD data and also the corresponding .HGT file ...
1
vote
0answers
15 views

Why the SRTM drainage crossing the Contour line (elevation) in toposheet. how to reduse this error

Drainage layer extracted from srtm data in ArcGIS. when comparing to toposheet field checking the drainage stopped before the (elevation)contour. but SRTM drainage crossing the Contour line how to ...
5
votes
1answer
97 views

Which is better for measuring actual ground elevation, NED or SRTM?

I know that NED DEM layers are created using mainly Lidar point clouds and that the SRTM derives its data from shuttle-based radar. I have both of these loaded into QGIS and can see that over my study ...
1
vote
0answers
26 views

How to get a multi-attributes vector from an SRTM raster in QGIS?

I split an SRTM raster into 3 different raster files representing the altitude, the slope and the exposure, using QGIS DEM analysis tools. How can I output a single vector file with the 3 attributes ...
1
vote
0answers
38 views

Generating continuous aspect surfaces from DEM with QGIS

I'm trying to extract aspect surfaces from different DEM sources at different resolutions in QGIS. I've had success working with SRTM-derived grids (3-arcseconds) and am trying to perform the same ...
0
votes
1answer
71 views

Where can I find SRTM DSMs (digital surface model)?

I'm interested in finding a 30 meter DSM (digital surface model that includes canopy) from SRTM with the hope of creating a 30 meter canopy height model. I know that it can be done because the ...
1
vote
0answers
34 views

Swapping bytes for SRTM 16-bit binary format in ArcMap?

I am using ArcMap 10.2.2. I have two .hgt files in 16-bit signed integer data. All I have done so far is to mosaic them together (Mosaic to new raster). Since the DEM data are provided in Motorola ...
6
votes
2answers
532 views

best and most accurate free DEM?

I'm working in France. I thought the TanDEM-X was a free and open DEM but that does not seem to be the case. According to a few websites, the most famous free DEMs seem to be ASTER GDEM, SRTM, X-SAR ...
1
vote
1answer
106 views

Displaying contour lines calculated from SRTM in Google Earth?

I'm relatively inexperienced in GIS, but would like to display contour lines calculated from SRTM data in Google Earth. It doesn't matter whether they are actual linestrings or just an image ...
1
vote
1answer
34 views

SRTM 1arcsec transformation in ArcMap?

I downloaded SRTM data from http://earthexplorer.usgs.gov/ (tile n49 e019 - North Slovakia and Poland). I need to project data into another coordinate system and projection, but I still have an 999999 ...
0
votes
0answers
22 views

building artificial dam in a canyon [duplicate]

I want to calculate the water volume dammed by a dam in a canyon. I managed to calculate the water volume but I actually need a dam in a certain place of the gorge so I can pursuit my calculations. I ...
2
votes
0answers
78 views

How to find mountain-peaks in SRTM TIFF

I'd like to identify mountain-peaks from an SRTM TIFF (created/composed from the original HGT ones). How I'd wish it would work: Check for each pixel whether it is the highest value within a given ...
0
votes
0answers
22 views

Cannot change an SRTM raster rendering with single band pseudocolour [duplicate]

I'm trying to colorize a SRTM raster in QGIS 2.10 following a tutorial found on the Ireland QGIS User Group Blog. My problem is that when I try to set the render type as single band pseudocolour in ...
1
vote
1answer
45 views

Problem with SRTM 30 m data while creating watershed

I have used SRTM 90 m in many of my hydrology projects for creating watershed and so far it has proven its worthiness. But, I haven't had any luck with its newer and high resolution SRTM 30 m ...
2
votes
0answers
51 views

Fixing undesirable lines between tiles from SRTM contour line extraction?

I'm trying to make a South American topography map based on SRTM data on QGIS. The problem is a visual one. If the topography contours are extracted from individual SRTM tiles, it results a little ...
1
vote
1answer
251 views

SRTM vs Google Earth Pro elevation data

I am working on elevation data for an area in Sudan. Between Google Earth Pro and SRTM elevation data, which one is more reliable?
-1
votes
2answers
148 views

full SRTM1 arc second download

I would like to download the new released maps (2014) SRTM1 but where can we find them? Is there an FTP server to download the whole images?
0
votes
0answers
24 views

Orfeo Toolbox DEM download error

I have been trying to use the following part of the Orfeo Toolbox to download DEM data from usgs. I have been passing it a geotiff image as the reference and am receiving the following error: 2015 ...
2
votes
1answer
70 views

Read SRTM HDG elevation files with C++ / Strange negative numbers (not Null)

I'm trying to write a little C++/OpenGL utility with which I could manage SRTM HDG files. For now, I'm just trying to read the files correctly. So I downloaded a sample tile from the main server, ...
0
votes
2answers
47 views

Equidistance on line contour from DEM

I am using a SRTM 30 meters for slope and elevation. When i'm using this 30x30 rasters to generate contours i set a 30m equidistance for contour, and the results are ok. Now i'm wondering if it's ...
0
votes
0answers
29 views

Defining and exporting a path from discrete points in QGIS

I'm working with elevation data (NED, SRTM, etc.) in QGIS and I'm wondering how I might be able to pick a set of points from my map and export the coordinates to something like CSV. For example, I'd ...
3
votes
1answer
298 views

SAGA tool 'Relative Heights and Slope Positions' - What do results tell me?

I am currently trying to get in morphometry, using the SRTM 30m DEM. I was recommended to test the SAGA mudule 'Relative Heights and Slope Positions' ...
0
votes
0answers
14 views

How to import or reproject SRTM 30 sec DEM [duplicate]

I downloaded the global SRTM DEM from here. When I add the DEM as a raster layer (in my case topo30.grs file) the left/western edge of the file is at Greenwich and the right/eastern edge is at +360 ...
0
votes
0answers
70 views

How to overlay dem (100m) over MODIS (500m) in square grid?

I have SRTM Dem data and the resolution 90m approx at the equator however the resolution varies as we move from equator to poles. For my case the study area is Himalayas. My plan is to get the square ...
2
votes
2answers
223 views

Does a SRTM DEM image show details such as fields?

I'm working through the QGIS Training Manual where I have a step to get ... ... raster images (SRTM DEM) which cover the region you have selected for your course. SRTM DEM can be ...
0
votes
1answer
102 views

How can I use the OSM SRTM plugin for Osmosis program?

I am using Osmosis and I have a test .osm map. I want to install a plugin from the following Github repo: https://github.com/locked-fg/osmosis-srtm-plugin/ I have followed the steps to "install" it ...
1
vote
1answer
133 views

Issues with getting the height from SRTM gdalwarp WGS84(EPSG:4326) to Mercator(EPSG:3857)

I am trying to use the SRTM .hgt file to obtain the height of a location. My issue is that I wish to reproject the SRTM file from WGS84 to Mercator but the height returned is not consistent after ...
1
vote
1answer
84 views

How to align ASTER GDEM with Google Maps?

I'm using ASTER GDEM V2 to pick heights at lon-lat coordinates obtained from Google Maps but I found that at some locations - particularly San Francisco: https://goo.gl/maps/w7p1K - the DEM seem to be ...
1
vote
2answers
541 views

How to effectively merge SRTM 1 arc data?

We have around 1800 1 arc-second SRTM tiles (Geotiff). How to effectively merge all the tiles into one single file ? We are thinking about splitting 100 files per folder and merge them together using ...
1
vote
0answers
82 views

Calculating position in SRTM grid

I'm actually trying to calculate a grid point position in a SRTM grid by row and column count. So I got a position by lat/lon, then calculating the row and column in my hgt-file (this post helped me) ...
3
votes
0answers
149 views

Interpolation of SRTM data

My situation: I need to interpolate the 3" srtm data for a game I'm developing (it's like Minecraft - voxel style). I downloaded the srtm data from viewfinderpanoramas.org. My aim is to get the height ...
1
vote
0answers
38 views

Resampling methodology when projecting a raster

When projecting an SRTM raster with "Project Raster" tool in ArcGIS10.2, what is the best resampling methodology, bilinear ot cubic convolution?
0
votes
0answers
135 views

Slope and Curvature values

From an SRTM DEM I have calculated the slope of the terrain with values that range from 0 to 77 (degrees). I have also calculated the curvature of the terrain and the statistical characteristics of ...
1
vote
1answer
231 views

How to obtain elevation value from given SRTM data on mouse click in web browser? [on hold]

I need JavaScript code for obtaining elevation data from SRTM tiff image. I have used Google APIs, but I need for downloaded SRTM tiff image. (SRTM file is being loaded on a base layer, and both ...
3
votes
3answers
131 views

Bad SRTM files?

I have noticed that between 1-3% of SRTM .hgt files downloaded for a continent when un-zipped are of TGA image, font image or text format and do not contain elevation data. Results are the same ...
4
votes
1answer
200 views

artifacts in SRTM contour layers processed with GDAL tools and rendered with mapnik

Here is my workflow for importing individual SRTM tiles into postgis using the GDAL utils and rendering a png using mapnik: gdal_fillnodata.py -srcnodata -32768 gdal_contour -i 10 -a ele -snodata ...
2
votes
2answers
135 views

Handling voids in SRTM3 data

When I actually work with SRTM 3 data in a meteorological application and especially when doing simulation over mountainous regions I expected and found a lot of voids in SRTM3 data. Has there been ...
2
votes
1answer
579 views

Read In SRTM HGT elevations using Java

I have read the following posts on reading in SRTM HGT elevations- How do you convert SRTM HGT elevations from WGS84 into meters above sea level? and How to extract elevation from .HGT file? I am ...
0
votes
1answer
369 views

Elevation value (in meters) from SRTM [closed]

How do I determine elevetion/terrain height value from SRTM data?
2
votes
1answer
138 views

gdaldem output file size explodes

I want to create a color-relief and a hillshade with gdaldem and use them with mapnik. System: Ubuntu 14.04 LTS Server, gdal-bin 1.10. Here are my steps: Download all SRTM tiles from ...
2
votes
1answer
114 views

how use height tag data in Project-OSRM

I am using Project-OSRM in my project . All is works . But I need use elevation data. Downloaded osmosis master . And SRTM plugin added to osmosis. Also this worked fine . SRTM plugin started and I ...
0
votes
1answer
261 views

how to batch reclassify rasters with percents range

Using Model Builder I need to reclassify slope rasters with percents range value. I have read and ask here batch reclassify rasters with different elevation ranges, but I still need more explanation. ...
3
votes
1answer
568 views

How to convert the SRTM DEM orthometric to ellipsoidal heights using ArcGIS or others GIS?

Recently I got the SRTM DEM from Cgiar,which based on WGS84/EGM96. and I merged the tiles to one tiff file. I want to get the WGS84 ellipsoidal heights. According the steps from the Arcgis Help 10.2 ...
7
votes
2answers
12k views

Download new SRTM 30 meters

I read about the new version of the digital elevation model at 30 meters (SRTM 30 meters), but I can not find from were I can download it. some sources: ...