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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0
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0answers
23 views

The size of the SRTM raster data cells?

The size of each cell of the SRTM 1 arc-second raster data is: 1 x 1 arc-second = 0.00027 x 0.00027 degrees. But of what? 0.00027 degrees of latitude x 0.00027 degrees of longitude? or 0.00027 ...
2
votes
1answer
204 views

NASA SRTM: precipitous contour lines in TileMill

I was trying to make a nice looking print map of Bali (Indonesia) in TileMill. After creating a terrain layer (using this walkthrough) I noticed that the island's coastline was precipitous. Is ...
2
votes
2answers
49 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
1answer
246 views

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

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 ...
2
votes
1answer
42 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 ...
1
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0answers
35 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
48 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 ...
7
votes
2answers
13k 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: ...
11
votes
5answers
6k 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 ...
0
votes
0answers
34 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
21 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 ...
12
votes
4answers
8k views

Using 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 ...
0
votes
1answer
306 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 ...
1
vote
0answers
58 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
104 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
31 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
39 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
81 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 ...
6
votes
2answers
585 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
0answers
35 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 ...
0
votes
2answers
1k 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 ...
6
votes
1answer
964 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
vote
1answer
122 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 ...
2
votes
0answers
53 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 ...
4
votes
2answers
708 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 ...
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
81 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 ...
6
votes
3answers
446 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 ...
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
48 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 ...
-1
votes
2answers
168 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?
1
vote
1answer
291 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?
0
votes
0answers
25 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
81 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
49 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 ...
3
votes
1answer
335 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
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 ...
5
votes
1answer
174 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? ...
0
votes
0answers
15 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
74 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 ...
0
votes
1answer
107 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 ...
2
votes
2answers
231 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 ...
3
votes
3answers
850 views

Gdal: how to get the max and min altitudes of my topographic raster?

Given a .tiff topographic raster image. How to get the altitudes of the highest and lowest point/pixel ?
1
vote
1answer
87 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
1answer
135 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
2answers
574 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
83 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
153 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 ...