Questions tagged [srtm]

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 in February of 2000. As of 2016, it is now almost universally available at 1-Arc Second resolution.

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18 views

Converting SRTM .hgt to GeoTiff with GDAL [closed]

How do I convert an SRTM tile into a GeoTiff with GDAL?
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Raster artefacts after saving to GeoTIFF in QGIS

When processing DEMs created using downloaded SRTM data (initially HGT files) I produce a nice-looking product; however, saving this as a GeoTIFF creates square artefacts which are plain to see (and ...
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53 views

gdal translate resampling -r flag has no effect?

Whenever I add a resampling parameter (-r) to my gdal_translate commands, it seems to have no effect. For example the following two commands produce a binary exact result. How can I get my image to ...
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How to add elevation data to tif to create DEM (SRTM satellite data)

I have a .tif created from the SRTM satellite data. The tif should already be DEM data as it was collected from the SRTM satellite. When I open the tif in ArcGIS, I don't see any height or z data, ...
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How can I export elevation layer data and OpenStreetMap layer data as shapefile in QGIS? [closed]

I am a newbie in QGIS looking to obtain elevation data with respect to a map. As I could not find any free elevation data, therefore I adopted the following approach. Elevation data: I got the ...
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Conversion of EGM96 to NAVD88

I am new to ArcGIS and geoids/ellipsoids, and I want to convert a dataset in EGM96 (the USGS SRTM DEMs) to NAVD88. I have the SRTM dataset from NASA downloaded and open in ArcGIS as .hgt files. I ...
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33 views

Why are SRTM tiles (*.tif) not visible in my QGIS project?

I am wondering, why my SRTM tiles are not displaying correctly in my QGIS (3.10.4 LTR) project. If I load vector layers to an empty QGIS project first, they are visible and the later added SRTM are ...
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27 views

DTED file project get squared by QGIS

I am quite new to the GIS world and I am trying to work with some DTED file from the SRTM project on QGIS. Unfortunately, when I add it as raster layer the program automatically shape it as a perfect ...
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NASADEM data around 180th meridian

I am following this thread What is NASADEM and when it will be released? and saw post from @markusN and start to download the data in nc format for few analysis in various countries. Recently I tried ...
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106 views

Load all SRTM data into PostGIS

I am trying to load all the SRTM data into a PostGIS database. I tried the process described here: https://postgis.net/docs/using_raster_dataman.html It created a giant SQL file. When I tried ...
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332 views

Use “SRTM Downloader Plugin” with “QGIS 3.4”

Edit (TL;DR): As Gabriel De Luca pointed out in his answer there is an open GitHub ticket about the issue. I would like to use "SRTM Downloader Plugin" with "QGIS 3.4" (OS: Win7, 64-bit). Now if I ...
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How to convert DHHN2016 to mean sea level?

I am new to GIS. How can I convert DHHN2016 to mean sea level? I am using this dataset https://www.opengeodata.nrw.de/produkte/geobasis/hm/dgm1_xyz/dgm1_05314000_Bonn_EPSG4647_XYZ.zip which I stiched ...
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How to compare two DEMs?

I am new to GIS and I want to compare two DEM raster .tiff files, i.e. I want to compute differences between height values etc. How can I determine if the two tiff files are comparable? I have read ...
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96 views

Adding elevation to shapefile in ArcGIS Desktop

I have a shapefile that's actually a polyline (but it's 200 miles!) on the other hand I have a SRTM layer with elevation data. How should I add the elevation data from SRTM layer to the shapefile? ...
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Converting “ALOS PALSAR” DEM to EGM96 vertical system using ArcGIS Desktop

I have downloaded "ALOS PALSAR" DEM from NASA's EOSDIS. Can you help me to convert the high-res DEM to EGM96 (like SRTM data)? I have used ArcGIS Desktop 10.7 edition but it does not work correctly. ...
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1answer
214 views

Least Cost Path Analysis in QGIS?

For my Bachelor's thesis I try to reconstruct a road betweeen two ancient cities. One method I'd like to try is least cost path analysis with QGIS. I've worked with QGIS before, but mostly only ...
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24 views

SRTM DEM data appear mismatching in BW/Saturation or even brightness when gathered

I'm trying to make a DEM data of Algeria as I tried to download about 15 SRTM data but when added on ArcGIS and gathered they appear with diffrent saturation/brightness each, I tried then again to ...
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25 views

Quality of SRTM 4.1 vs 2.5

In recent years I have used this source https://dds.cr.usgs.gov/srtm/version2_1/SRTM3/ to retrieve elevation data from files in .hgt format. The problem is that these data have holes, so I'm looking ...
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1answer
45 views

SRTM Data tiles appear to be different scales

I have downloaded the STRM files (.bil) for Hawaii and rendered them in QGIS. They render as grayscale heightmaps. Although all of the tiles appear to line up, none appear to be using the same scale. ...
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1answer
69 views

Move GeoTIFF file to another coordinate of lat and lon [closed]

I have a GeoTIFF file that corresponds to terrain data (SRTM 3-arc data). I need to do 3 things; Crop a specific area of ​​the raster and Literally move the raster to another coordinate of lat and ...
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63 views

Which layer for least cost analysis?

I'm new to least cost analysis. I have a DEM-layer of a region and I want to know what's the least cost path from a to b. Do I have to use the DEM layer to calculate that? I also have a hillshade ...
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76 views

Which layer for least cost path analysis

New QGIS user here, so maybe it's kind of a stupid question. I want to calcualte the least cost path between two points but I don't know which layer to use. I have two layers, one is a hillshade layer ...
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Stack for creation local shaded elevation tiles

I wish to create a local osm tiles with elevation information. I wish to display elevation info like a contour lines and shaded places linked with contour line values. I know about this source/...
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164 views

Removing noise selectively from DEM using QGIS?

I am looking for a processing tool that can remove noise selectively from a DEM (Mostly SRTM). My current workflow includes "Fill sinks" and "r.neighbours". The problem is that the tool is blind to ...
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1answer
160 views

QGIS raster merge results in a black rectangle

I have 4 SRTM raster like this: I want to merge them into 1, but when I do this, something like this happens (I only tried it with two of them here): I also tried changing the min and max values ...
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48 views

How to specify HGT file name in gdal_translate command?

gdal_translate command is generating a HGT file with user defined name but its giving an error as `N5464347W74.hgt' not recognized as a supported file format. Below is the command and the entire ...
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2answers
65 views

How to use gdal_contour to APPEND data?

I'm trying to import contours from SRTM HGT files. First try (nice): gdal_contour -f PostgreSQL -a elevation -i 10 srtm/S01W069.hgt "PG:host=volcano-db user=postgres password=guesswhat dbname=...
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2answers
504 views

Remove border lines of SRTM tiles rendered as hillshade

I have downloaded several SRTM DEM raster tiles from https://dwtkns.com/srtm30m/, and created hillshade versions from the tiles. However, upon closer inspection, the hillshade tiles now have border ...
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64 views

HGT Elevation vs Calculated Elevation

I wondering how to interpret the elevation calculation. Per example. We are in Canada and I use SRTM3 files. I use the GDAL library to extract my elevation, everyting is ok, except: Why (or how) the ...
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1answer
779 views

How to convert a TIFF file to HGT file?

In my project I needed to convert TIFF file to SRTM data and came up with following warning/error. gdal_translate -of SRTMHGT Terrain.tif Terrain.hgt Output: Warning 1: The source projection ...
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187 views

Print elevation of different coordinates from .hgt file [closed]

I am trying iterate through the data(elevation) from .hgt file. I have attached the codes which i used to get the elevation from the file. from gmalthgtparser import HgtParser hgt_file='N09E076....
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54 views

CGIAR SRTM to xyz using GRASS GIS, with sampling

I have used CGIAR interface to select the tiles, like so: This resulted in a bunch of *.zip-files, and I have extracted them all into a directory. Next, I followed the instructions as https://...
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2answers
1k views

How to open .hgt files on QGIS 3.2?

I have downloaded a hgt file from EarthExplorer but when I try to load it on QGIS I get an error "GDAL provider cannot open GDAL dataset". I was under the impression that hgt files were supported. It ...
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Trouble matching SRTM data clip to slippy tile extents

I'm trying to extract the SRTM data for some slippy tile in QGIS, and it doesn't seem clipping to the right extents. Here are some of the data for the tiles that I'm using to test (this data comes ...
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Converting SRTM to UTM makes pixels non-square [duplicate]

I have a SRTM originally set to EPSG 4326. I need to convert it to UTM (EPSG 31983), in order to generate viewsheds. The original version (EPSG 4326) has square pixels (0.000833333 x 0.000833333) ...
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1answer
632 views

Merging several .hgt files into one

I'm currently struggling on trying to combine several .hgt files with different software. I can get the 4 tiles into any kind of software but my issue is exporting the file back to .hgt file. I've ...
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194 views

Generating a Map (like Google Maps) using HGT files

I'm doing a programming project. It consists of generating a Map (like Google Maps) from height files .HGT Currently, I can read each file .hgt (each .hgt file have 1201 * 1201 elevation data). For ...
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2answers
135 views

Mapping coastline geometry with SRTM raster?

Working on a map that includes a bathymetry layer, SRTM data for hillshade, and an accurate coastline boundary edge. I noticed though that the pixel resolution of SRTM 90m resolution creates visible ...
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How to evaluate the hilliness of an area using SRTM data? [closed]

I want to evaluate the hilliness of an area (e.g. municipality) using SRTM data. I thought about just calculating the standard deviation of the raster cells but my gut feeling is that this approach ...
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1answer
222 views

SRTM/DEM 1m resolution (batymetri) to point [closed]

I have bathymetry data (1 huge data) = SRTM/DEM/FGDBRaster (0,9818m resolution pixel, floating, 32 bit, 45 GB size) and an alternative data (split into small pieces data) = same data but with 1m ...
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1answer
122 views

Reconciling elevation difference between SRTM and old US Army map in Laos?

In QGIS I georeferenced a 1970 US Army contour map for part of southern Laos (20 m intervals) with the following indicated properties: Horizontal datum Indian datum 1960 Spheroid=Everest Verical ...
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1answer
472 views

Getting correct elevation from hgt file [closed]

When reading SRTM3 data from a .hgt file I get the wrong elevation of a specific latitude longitude and I can't see why. Maybe someone can see the problem ? My coordinate is near Lissabon in the sea ...
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781 views

gdal_warp with huge tif: integer overflow

I retrieved the SRTM 1" data and merged it in one huge tif. Now I want to warp it. It's working fine for low resolution (eg 5000, 1000, 500), but it doesn't for 90m resolution. I'm using this command: ...
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Can SRTM preserve topological feature well?

There are studies on SRTM data vertical elevation accuracy, which seem to indicate that there are around an average of 5m vertical error when compared with a DEM derived from cartographic maps. ...
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471 views

Which DEM format is efficient .tiff or .hgt

I know this is a vague question, but I've no expertise in GIS world. I was building this terrain map for a game like simulation project that I'm invested in. Data accuracy is least or no concern, but ...
2
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1answer
187 views

What is the absolute vertical accuracy and the relative vertical accuracy of SRTM 1-arc second?

When I was looking for the accuracy values for the srtm dem, I found research papers trying to find out these values for its own selected area of study, some of them assume that the absolute value in ...
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1answer
100 views

r.viewshed output location

I'm very new on GRASS and trying to extract the viewshed of a SRTM HGT file. This is what I've done so far: (why I'm using GRASS command line this way is not in question. Please answer this same way) ...
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115 views

SRTM/ 90m DEM - slope calculations

I have a question relating to a comment in a closed discussion (Does a value in srtm dem file refer to the center or corner of a cell?). The comment was following: "When talking about any DEM, it's ...
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1answer
624 views

Code to read elevation data from HGT file

I'm trying to read elevation data from NASA HGT file. I've started from Extracting elevation from .HGT file? and have changed this code a little to keep it simple and to use 1-ARCSEC (30-meter) data ...
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317 views

GDAL merge of DEM data resulting in large black tiles, elevation min/max problem?

I am new to QGIS (former Arc user) and having trouble with the raster merge tool. I am merging 7 tiles of SRTM arc 1 data to cover a province in eastern Ecuador. Data is resulting in large areas of ...