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

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3
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1answer
49 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 ...
3
votes
1answer
19 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
32 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
18 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? Thanks!
1
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1answer
18 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
25 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
30 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 q gis. So far so good. My problem is that I don't need an air-line distance of 25 km around the points, but a "real ...
0
votes
1answer
30 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
25 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
56 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
70 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 ...
1
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0answers
18 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 ...
1
vote
0answers
21 views

How to create a numerical mask file with the elevation points of an area with QGIS

I'm using QGIS and I have to create a mask file (.txt) as an input for a hydrological model. The file should be a numerical grid map that represents the elevation points of a catchment area, like the ...
1
vote
0answers
42 views

Elevation Profile Google

I am creating a longitudinal profile in Google Maps. For this, I created a function that lets you draw a line and when it disappears just drawn. So far there is no problem, but when I return to view ...
0
votes
1answer
30 views

Intersect elevation interpolated from CAD file in ArcGIS

I have two datasets - contours and vector (water, roads,...) Vector layers were used as breaklines to generate the contours. Then the contours were generalized a bit. For quality check I need to ...
1
vote
1answer
76 views

Making DEM from contours without elevation data?

I got a shapefile with contours, but no elevation data is present. We can assume as known info, that the contours mark elevations at known steps (say, 20 m). Is it still possible to restore the ...
2
votes
2answers
88 views

Generate TIN from elevation data in Python (no Arc)

I would like to generate a 3d terrain model of an area, and I am stuck on creating the TIN (which I will convert to an STL). I know there are plenty of ways to use ArcGIS, QGIS, 3DEM, and various ...
1
vote
1answer
44 views

Getting elevation readings at any lat,lon from shapefile with scattered irregular points

I have a set of x,y coordinates, each of which I'm trying to get an elevation reading for. The elevation data source, however, is not a regular grid, but consists of a shapefile containing scattered, ...
2
votes
1answer
71 views

How to find a point with highest elevation in area using ArcObjects

Is there a way to find a point with highest elevation in specified area by using ArcObjects? Let's say that I have a raster with DEM and I would like to establish some areas of interest in this ...
1
vote
2answers
122 views

Determining Min and Max elevation in Python using GDAL? [closed]

I have a DEM file and shape file of specific area ,and i want to Create a module in Python that writes name of each area which is shows in the picture, with the greatest differences in altitude on ...
1
vote
1answer
37 views

How large is the entire ASTER Global DEM on disk?

I see from various online sources (including GIS.SE's own How to download the entire ASTER GDEMv2 dataset?) that the ASTER GDEM has 22'000 tiles, each 1°×1° and 3601×3601 pixels (each pixel being ...
1
vote
1answer
40 views

Regarding Atmospheric correction and Elevation DEM Projection system

I am trying to conduct atmospheric adjustment of Landsat 8 image bands using 6s algorithm (i. atcorr grass gis tool). It seems, in the input section, an elevation raster map should be provided. In my ...
1
vote
2answers
47 views

Changing height/interpolation/shape of raster layer

I am kind of a beignner in ArcGIS and thought about and googled this problem for two days now. I am working in ArcScene making a 3D visualization of a bedrock surface of a town. I have a polygon ...
0
votes
0answers
20 views

Predicting Potential Areas of Eagle Nests based on Slope and Elevation using Mean +- 1 Standard Deviation?

I am trying to predict Potential Areas of Eagle Nests based on Slope and Elevation using the Mean +- 1 Standard Deviation as the potential range that eagle nests could occur. I have data about known ...
0
votes
1answer
70 views

Reset a base elevation in Pix4D?

Does anyone know how to set a baseline elevation in Pix4D, or is that something that has to happen on the drone-capturing side? The reason is that I have an area which is flown with LiDAR, several ...
0
votes
0answers
19 views

How to connect slope values from dem to polyline layer in ArcGIS?

Is it possible to connect those elevation data from raster to polyline layer? I need to create a network analysis for the best way with the smallest elevation difference. Cheers, Kate
1
vote
1answer
49 views

MapServer & Raster picking / Elevation data

I have some GeoTIFFs with elevation data, displayed in OpenLayers or Leaflet via WMS from MapServer. I need to be able to request (from the client) the elevation at some point clicked by the user. ...
2
votes
0answers
55 views

High-level method for offline future road elevation data

I am new to GIS, so please do not hesitate to call me out in providing limited information. I have a .tiff Terrain (elevation) data file for the east coast of the US and a .osm.pbf OSM file for ...
1
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0answers
21 views

Export 3D data dxf file problems with elevation value

I have the problem that i can´t export a shp file into DXF and include the eleveation value I make all the procedure explane on "export 3D data dxf file 4" but each time I have the folow error: ...
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0answers
43 views

Getting Z values from source points to transfer to points digitized from them?

I have a set of points that I bring into ArcMap as a shapefile, these contain X/Y coordinate data as well as Z data (Elevation). I am using this to digitized from so when I make a new point file I ...
1
vote
1answer
126 views

QGIS elevation and relief shade

I am trying to generate a map with terrain and elevation in QGIS and as a beginner I have followed tutorials on how to generate contours and hill shades succesfully. However, I don't know what are the ...
0
votes
0answers
53 views

Help creating a 3D elevation map using ASTER DEM .TIF image [on hold]

I am trying to figure out the whole process behind creating a 3D elevation map of a region that I have downloaded ASTER DEM data for.
0
votes
0answers
42 views

Terrain elevation in QGIS

How can I get started with creating a map with elevation just like this one: Basically I need a map that looks like the one above. Can someone tell me where can I get the data, and how do I process ...
2
votes
1answer
60 views

Adding elevation data to a network dataset

I am trying to add elevation data to my road network to more accurately calculate walking distance to and from schools. I have figured out how to do the network with out elevation, but for the life of ...
1
vote
1answer
150 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
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0answers
31 views

Convert .adf file to grayscale heightmap

I have downloaded a zipped folder containing multiple .adf files with elevation data from http://viewer.nationalmap.gov/. I want to create a 16 bit grayscale heightmap (tif) from the downloaded files ...
2
votes
1answer
98 views

How to make slope map from elevation map in Lat/Long?

I have an elevation raster map of the world, in Lat/Long. When I make a slope map, the results of the raster cells will be either 0, or values close to 90. The problem seems to be that the Slope ...
0
votes
1answer
62 views

ASCII Raster format cellsize

I have a particular .asc file, with elevation data in it. I am wondering if somebody knows, what is the unit for the "cellsize" variable in the header of the .asc file? Here is how the header looks ...
1
vote
1answer
43 views

How to return elevation for point data in QGIS?

I have a dataset for the Western USA and want to get elevations for the point data added to the point attribute table. What is the best way to batch process this so the whole operation is done at one ...
1
vote
0answers
33 views

GPS point elevation vs Contours layer elevation

I have some survey grade GPS points whose elevation is approx 55 feet lower than my contours layer elevations. I am using 1 ft contours and comparing point elevations with contours in the same ...
2
votes
1answer
91 views

Find lakes on an elevation raster

I would like to know if there is a way to identify lakes based on an elevation raster (like SRTM or ASTER)? As far as I can understand, it would mean identifying any cell below the elevation of ...
2
votes
1answer
55 views

How do I find out the sea levels?

I have following elevation data of a region (the higher the altitude, the brigher the points): How can I find out, which areas are filled by water, and which not? Can I assume that if the ...
1
vote
1answer
84 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 ...
1
vote
2answers
107 views

Suitable raster format for elevation data with sub-meter accuracy?

I've got some elevation data represented in ascii gridded xyz-files which I want to convert to a conventional raster format. What's a bit special is that the elevation values have sub-meter accuracy, ...
0
votes
1answer
58 views

GRASS 7 Cost surface and elevation points development

I'm a new to GIS and I need some help. At the moment, 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 ...
10
votes
3answers
666 views

What is the meaning of “Elevation above the surface of the ellipsoid”?

I'm using implementation of Vincenty's algorithms, and I have their class called "position" that requires lat, lon, and elevation defined by: "Elevation above the surface of the ellipsoid". What is ...
5
votes
1answer
541 views

How to find all points with certain elevation difference between them in QGIS

I have a point layer (xyz) and want to find all points that have elevation difference of 200m or more. I would like to then draw a line between each pair with the largest elevation difference. The ...
0
votes
1answer
55 views

Regarding ARCGIS Curvature values [closed]

I originally had a DEM .tif raster in Decimal degrees. I projected it into a PCS with the spatial reference in ArcGIS as: WGS_1984_UTM_ZONE_44N Then, I took the Curvature tool and with a Z-factor of ...
1
vote
2answers
83 views

Topographical Elevations for Central Africa and Cameroon

I am using QGIS and I have been faced with the problem of topographical maps. From searching online I could only find data for the United States. Google maps offers elevation contours, however I am ...
0
votes
0answers
46 views

Which elevation data source has the highest precision for Russian Far East?

If I want to get data on the elevation around the city of Artyrom (region around 132.159633, 43.350116), which elevation data source has the data with the highest precision for that region? I found ...