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

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10 views

Create and save profiles of lines automatical in QGis or Arcmap [on hold]

I have one polyline vector with 700 polylines and one raster file. I would like to make the profile of all polylines automatically and save it as csv or xls file. Associated with one polyline I have ...
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1answer
22 views

In R's raster::terrain function, which way is north?

The terrain function in R's raster package calculates slope and aspect from an elevation raster: see http://www.inside-r.org/packages/cran/raster/docs/terrain. With the unit="degrees" option, the ...
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1answer
61 views

Extract height values from vector to CSV

I have generated a CSV file (using the MMQGIS plugin) expecting to obtain all the coordinates of a vector layer that I have created. But the output file only contains the latitude and longitude ...
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2answers
58 views

How do I convert XYZ coordinates to another projection system

I am trying to convert between coordinate systems in QGIS. I have a point file in NZGD49 coordinates (EPSG:27200) (referenced to the geoid) which I am trying to convert to NZGD2000 coordinates (EPSG:...
3
votes
1answer
23 views

Are there any tools that can identify ravines/steep elevation drops from contour line data?

I am trying to create polygons around rivers that extend all the way up to the top of the surrounding slopes. I am currently able to do this using stream data and contour data, but I would have to ...
0
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1answer
18 views

Google Earth - Color Coded elevation data

I don't know anything about Global Information Systems. I want to do something which should be extremely simple and extremely common sense I have Google Earth Pro. I just want to see a color-coded ...
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2answers
60 views

Extract elevation data from contour lines

I am working with QGIS. I used raster-extract-contour to get contour lines from a raster image. Now I want to break up my single vector file into multiple layers based on elevation. How do I do this?
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0answers
34 views

Interpolating Temperature over Elevation on ArcMap

I need to overlay or create a new image file in ArcGIS that overlays temperature point data I have for California onto a 30m resolution DEM for that state. I have explored Co-Kriging, however I have ...
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0answers
11 views

How to render elevation polygons as concentric polygons with increasing order of their height at given point in geoservert

I have create a postgres database that contains the elevation polygons at various elevation heights of sachsen. I wish to render these elevation polygons in a similar manner as they appear in the open ...
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1answer
17 views

GPX to Feature loses elevation

I have been sent a GPX file to create a trails network on arcgis. When I run the GPX to Feature tool the elevation attributes are all zero, however when I view the GPX file on an online view, there is ...
5
votes
1answer
71 views

Update from/to Z from attributes using arcpy Update Cursor

Trying to update Z values onto some point and line features from the level attributes on each feature. My script works fine on points - the previous Z values of 0 now have the same values as the ...
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0answers
13 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 ...
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1answer
27 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
41 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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0answers
65 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
56 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
42 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 ...
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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
40 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 ...
2
votes
1answer
52 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
31 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
81 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
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
58 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 ...
3
votes
1answer
71 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 ...
2
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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 ...
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0answers
49 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 ...
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0answers
27 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 ...
2
votes
1answer
30 views

How do I know topo layer contains DEM-altitude? ArcMap 10.3

How do I know if a topographic layer contains DEM-altitude? ArcMap 10.3
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1answer
74 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
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3answers
49 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
172 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
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1answer
35 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 ...
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0answers
77 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 ...
3
votes
3answers
173 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 ...
2
votes
0answers
35 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 ...
2
votes
1answer
95 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....
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0answers
20 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
130 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 ...
4
votes
4answers
175 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 ...
2
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0answers
50 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 ...
1
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1answer
72 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?
1
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1answer
32 views

How do I extract elevation data from a DEM using points I have in a CSV?

So I have a CSV with a lot of fields. The first 3 fields are the ID, longitude, and latitude. I have already converted to decimal degrees, and said to display XY data. (Is there something else I need ...
1
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0answers
31 views

I have a .adf file and want to select an elevation range [closed]

I'm super new to GIS. I downloaded a USGS 30m resolution map of a bay, and now I want to specify all areas that are between 0m and -30m elevation. I need to find where a defined area contains 0 and -...
1
vote
0answers
57 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 ...
0
votes
1answer
44 views

How do you identify cuttings / crevices from a DTM or DSM using ArcGIS?

I am trying to identify where cuttings and crevices exist by using a DTM or DSM. My ultimate aim is to find where roads and rail lines sit within a cutting i.e. the land either side of them is higher ...
2
votes
1answer
108 views

Setting elevation data for tie points in Pix4D

I am currently working in Pix4D and am trying to assign elevation data to my selected tie points. I have aerial images taken using a camera with GPS from an aircraft and am working with a fairly ...
1
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0answers
82 views

Discovering highest point in area using QGIS?

I'll preface by saying I've never used or even heard of GIS software previously, so I'm sorry for being very clueless. My goal is to find the highest point in Highgate (in London, England). I have ...
1
vote
1answer
129 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 ...
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0answers
36 views

Importing DXF - Polylines with elevation data

When importing a DXF file (containing 3D contour data) to QGIS, none of the various methods described elsewhere are retaining elevation data as an attribute. e.g. DXF2SHP, GRASS v.in.dxf, opening ...