The vertical distance of a point or object above or below a reference surface or datum (generally mean sea level).

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7 views

Referencing DEM tif to MSL using GDAL?

I have a single band DEM tif representing elevation. How can I reference it to a datum and convert it to MSL altitudes? I'm using GDAL command line tool but don't know where to start. I looked at ...
15
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4answers
11k views

Where to download free elevation data for Europe?

Where can I find free elevation data for Europe? Please mention the available resolutions and terms of use when posting a source.
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4answers
362 views

Calculate mean elevation over a region

For the purposes of spatial interpolation, I have created a grid using "Create Fishnet" in ArcMap10.2 (I use the "label points", which have a spacing of 0,00833333 degrees). For every point (label ...
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1answer
1k views

How do I add elevation data to a GeoJSON line from a GPX file?

I understand that elevation can be added as an optional third value in Coordinates (lat, long, elev) in a geojson file, but I can't find a way to actually do that from a gpx file. I've used ogr2ogr to ...
2
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1answer
260 views

How can I calculate elevation from relief?

I have an SDE Raster that displays relief, but I want to display elevation. How would I go about doing this?
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2answers
3k views

how do you identify ridges on an elevation raster?

I was wondering whether anyone might be able to tell me in layman's terms how to extract or differentiate between ridges and hilltops from 10m elevation data using ArcGIS 10.1?
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1answer
26 views

How to find lowest elevation change using raster data and w.r.t muliple polygons

I am trying to complete a spatial analysis which yields areas (parcels of land) which are comprised of polygons (in an attribute table) that correspond to the lowest land slope regions or smallest ...
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1answer
72 views

GRASS 7 Cost surface and elevation points development

I'm a new to GIS and I'm trying to develop an optimal path across an area by using GRASS 7 features. It is very similar to the task given here. The problem is that I don't have any data with ...
1
vote
1answer
245 views

Generate 3D elevation points grid from 3D contour lines!

I have a shape file with 3D contour lines. I want that based on this information to generate for all this area a 3D grid of points with certain distance from each-other like every 50cm. I use ...
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1answer
38 views

Where to get free seafloor elevation for Galapagos Islands?

I'm trying to find seafloor elevation around the Galapagos Islands. Something with resolution 30 - 100 meters. Or just shaded relief for this region.
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2answers
199 views

Where do I get Elevation Data for Scotland?

So I am new here and I arrived here because I have been searching for quality elevation data for the entire Scotland but I have not succeeded yet. Kindly help if you know where to get the data Raster ...
2
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0answers
60 views

How to show a 2.5D surface of raster above terrain layer in Cesium?

I'm developing an web application that will show surfaces of rasters and terrain. These rasters are on GeoTiff format. I learned from example cesium can show image overlays earth surface. The ...
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1answer
55 views

How to select lines affected by sea level rise?

I'm doing a part for my master's thesis where I'm trying to find out which sites located near the coasts of Sweden that will be affected by sea level rise. I got a DEM with height data and have to ...
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1answer
41 views

Creating an elevation profile along a KML road based on ASC files

I want to make the elevation profile of a road in KML. I've found this online tool but its does not gives accurate elevations. I already have .asc files of the whole area that includes the KML route ...
4
votes
4answers
152 views

Google Earth Polygon surface area to follow the curvature of the earth model

Question: When drawing a polygon in Google Earth with latitude, longitude and elevation values at each node, how do you ensure that the surface area of the polygon also represents the desired ...
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vote
1answer
253 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 ...
1
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0answers
44 views

Averaging elevation for fishnet points in ArcGIS for Desktop? [closed]

I have a problem with adding average elevations for fishnet points. First of all I surveyed an area boundary of 16km2 using total stations. I got nearly 800 points to finish the boundary in this way. ...
3
votes
1answer
35 views

How to find elevation highest and lowest for a state or city

I am trying to find out the highest and lowest elevation for these types of geographical areas: continent (lots of ways to get info) country (lots of ways to get info) state (for the US states no ...
1
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0answers
97 views

How to request elevation data from ERDAS Apollo?

I'm developing a custom application(Desktop based using uDig SDK) where user have a provision to select the line feature on map to view its elevation chart. So far I can do this using Google ...
19
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4answers
8k views

How to download the entire ASTER GDEMv2 dataset?

In October 2011, NASA released the new ASTER GDEM global dataset (30m) and I have been wanting to get my hands on it. The only problem is that it takes forever to download and I do not feel like ...
1
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1answer
157 views

QGIS - Level curves - Voronoi Polygons

I am facing a difficulty in QGIS (2.8.2): I have three layers: layer 1: layer with points layer 2: layer of level curves (contour lines) layer 3: layer of Voronoi polygons obtained from the points ...
2
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1answer
44 views

How to calculate mean elevation in a DEM between a specific interval?

I have a DEM with different elevations between 100 m & 3828 m. I just want to calculate mean elevation higher than 1500 m? Can I do that?
2
votes
1answer
29 views

contour lines/ basement contour extraction

My purpose: getting out area between elevation contours (like b/w 600m and 700m). The contours could either be elevation ones or the basement contours. I got elevation contours using spatial analyst ...
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0answers
57 views

How to create an elevation profile in google earth from a kml?

I have a KML file of a stream that I originally created as a line shapefile in ArcMap (one stream extracted from a larger watershed data set). I need to create an elevation profile of this stream. ...
3
votes
1answer
60 views

Reading 1/3 arcsecond DEM data using C++?

I am writing my own application to use and present elevation data. So far, I've been easily using the three arc second SRTM data presented in ArcInfo ASCII format. But now I'm looking to use the ...
3
votes
1answer
64 views

Calculating median elevation for local authority areas using OS Terrain 50

I haven't been able to find anything that could comprehensively help me with my problem. I want to calculate median elevation for UK local authority areas. So far I've taken the OS Terrain 50 data ...
0
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1answer
53 views

Get Elevation of XY points [duplicate]

I am working with ArcMap 10.3. I have imported DEM files. When I imported the files they had the extension of .DDF. I would now like to be able to take a list of XY coordinates and, for lack of a ...
7
votes
4answers
922 views

Precision vs Resolution in elevation data

Update: A good example of something I am confused about: on the Wikipedia page for "digital terrain model" one can find the following statement about a satellite in the "See Also" section: TanDEM-...
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vote
1answer
940 views

Using GDAL in python to read elevation at a point from dted files

How do I get the elevation at a certain point using gdal to read in a dted file? I don't see much useful information out on the web. I'm sorry I should have been more specific. How would I ...
2
votes
0answers
26 views

Does USGS 3DEP data use a hash or checksum?

I'm downloading some USGS 3DEP elevation data, e.g., the file at the following URL: https://www.sciencebase.gov/catalog/item/563afea8e4b0d6133fe7357b The "ID" of this file is given in both the URL ...
0
votes
0answers
34 views

Convert EGM96 gps elevation to WGS84 ellipsoid elevation.

I have GPS elevation data (300k points) in EGM96. These points are located on the East US coast. I realise i need to work out the difference between the EGM96 and WGS84 ellipsoid in this region to ...
1
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0answers
26 views

How to find roads with similar incline?

I have no prior GIS experience, so please bare with me. What I'm trying to do is find a road (or a portions of road) from one country that is similar to another road(or portion of a road) from a ...
0
votes
1answer
57 views

Obtain free DEM data of South China

Is there any free source of Digital elevation model of China with the resolution of 30 meters or better and vertical accuracy of +-5m. Something along those lines
2
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1answer
30 views
6
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3answers
5k views

How to create contour lines from point data using QGIS?

I'm using QGIS 2.4.0 and I have a shapefile of points with elevation data and X and Y coordinates. I'm using windows 7 OS. The idea is to create a contour line SHP using my point data. My question ...
24
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5answers
2k views
0
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3answers
47 views

I have many points (the points have elevation) I want to remove some points that are too close together

How I can select points in a buffer (just each buffer) and among them choose a point that having more elevation? (in ArcMap) (Each point can be in several buffer and as each buffer can have multiple ...
4
votes
1answer
161 views

Interpolate temperature data (shapefile) using R

The answer below solved my fist question, so I edit my question as follows: I have a shapefile given with the attributes lat, lon, elevation and temperature. So far I have a script that interpolates ...
1
vote
0answers
55 views

How to create buffers having regard to topography with QGIS

I want to create buffers of 25 kilometers around points in a point-shapefile with QGIS. My problem is that I don't need an air-line distance of 25 km around the points, but a "real distance" having ...
1
vote
1answer
33 views

How to add hypothetical values to a raster?

I have to create Non-Regulatory Products for a few FEMA regions. Right now I am working on the 'Increased Flooding Scenarios' where you add a hypothetical value to the existing Base Flood (1', 2', and ...
3
votes
3answers
162 views

Get rivers from a DEM raster

I am new to spatial analysis and even newer to hydrology. I have a 30arc DEM elevation raster and I was wondering if I can use it as an input to get the approximate presence of rivers in a ...
0
votes
0answers
71 views

Elevation profile of river in R

I would like to plot the elevation profile of a river (shapefile, single line) in R. How do I extract the elevation values (from a DEM .tif, for example) for the river line. I tried clipping but that ...
1
vote
1answer
67 views

Free Digital Elevation (Terrain) Model of Europe or Germany

Is there any free (or not expensive) source of Digital elevation model of Europe or Germany with the resolution of 10 meters or better and vertical accuracy of +-5m or better?
2
votes
1answer
867 views

DTED/GeoTiff layer: Get elevation under mouse pointer

I have a simple desktop app with a map control. The map data that will be available to show will be either DTED files (Military Analyst's catalog / MADTEDLayer), or GeoTiffs (created by gdal). I want ...
2
votes
1answer
79 views

Download of very detailed DEM files for Portugal?

Operating system: Windows 10, 64 bit. QGIS Version: 2.13.3 which I installed via the QGIS.org website. I need contour lines for a small area in Portugal. I saw a guide posted here: http://planet....
2
votes
0answers
32 views

QGIS estimate height of feature vertices from TIN

I have a TIN representing a digital terrain model, and another polygon layer representing features (e.g. building outlines) which is assumed to 'sit' on top of the DTM. How do I calculate the ...
0
votes
0answers
19 views

Elevation data from floating point DEM in ArcGIS for Desktop? [duplicate]

I have acquired a DEM from local municipality. It is a float point DEM, and the elevation of each pixel is represented as simply "pixel value". What would be the correct work flow to convert this to ...
5
votes
1answer
120 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
1answer
118 views

How do I assign elevation labels to a custom set of points in QGIS?

Im trying to create topographic surveys using georeferenced images from a drone and a DEM/orthomosaic which has been created using Photoscan. I've managed to create contours and label them with ...
2
votes
0answers
49 views

How to get the most accurate elevation reading for the ground floor of a building?

I am looking into a way to calculate the elevation of the ground floor of many buildings in a study area. My plan is to run the building centroids against an elevation grid to get an elevation ...