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

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2
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0answers
7 views

Computing the elevation angle of a GPS satellite with respect to the given receiver location

can anyone source an explicit formula for calculating the elevation angle for a GPS satellite as seen from a receiver. I can't seem to find one. Even a text reference would be great. I couldn't quite ...
1
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0answers
14 views

How to merge elevation from a raster image onto a shape road network with QGIS? [duplicate]

I have a shape file with Stockholms road network and a raster image with elevation data from the same area. Is there any way to merge the two somehow, either by adding the slope direction as ...
0
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0answers
11 views

How to calculate fastest bicycle routes in Stockholm with QGIS?

Hello StackExchangers, I would really appreciate if expert users could point out a few directions for me, this is what I wanna do: Access an online map from my iPhone that gives me the possibility ...
3
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0answers
36 views

How to extract elevation data Google Earth?

How do I extract multiple elevation values for a particular area in Google-Earth all at once? I've only been able to manually pick them one by one when I enter the long. and lat. for each point.
6
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2answers
101 views

Reducing elevation from DEM using ArcGIS for Desktop?

I am so curious how would I strip off elevation from the DEM. I don't know how I would explain it further but I have attached an image to clarify this. I wanted to eliminate the area shaded with ...
2
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1answer
36 views

shapefile to gmt format

I have an ESRI shapefile of the contours of my study area, and I want to convert it into a format that is acceptable by GMT, so I can make an elevation map of my study area. Is that even possible? ...
2
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0answers
24 views

Can I use the Google Elevation API for academic research (licensing)?

I would like to use the Google Elevation API to generate about 5 elevation maps for master's degree research on aircraft collision avoidance. The data would be meshed and used in simulation to ...
2
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0answers
40 views

best method for gridding or interpolating elevation data

I wonder if someone can recommend the best method for gridding elevation data in QGIS, GRASS or similar. The elevation data I have is collected along 1m spaced lines at approximately 1 reading per ...
1
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1answer
59 views

Using GDAL to read 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
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1answer
74 views

How to create contour lines from point data?

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 ...
0
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1answer
43 views

Extract elevation data from Landsat / MODIS imagery?

Just curious, have anyone tried to extract elevation data from LANDSAT or MODIS imagery? So far, I came across one journal by Toutin who did so using adjacent LANDSAT 7 imageries. Results seem pretty ...
1
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1answer
113 views

How to extract elevation information from contour lines?

I'm working with OS windows 7 and using ArcGIS 10.2 and I have a point shape, which I must extract elevation for every point in it but the only useful data is a contour line shape. Not sure if it's ...
6
votes
1answer
140 views

How to get elevation profile from .tif dsm on the web map?

I have my dsm .tiff file, pixels are floating point 32bit values giving the terrain elevation in metres. I need to create a web map where user can draw a path and get elevation profile for that path. ...
1
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0answers
51 views

SRTM elevation data question

I have a question concerning the SRTM elevation data (http://srtm.usgs.gov/). As a little thought experiment, assume I want to build a 3D model of the earth's surface as a point cloud. The earth's ...
0
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4answers
70 views

Using Arcpy, how can I determine min and max elevation from a raster DEM layer within my current extent?

Using Arcpy, how can I determine min and max elevation from a raster DEM layer within my current extent? I'm currently using Data Driven Pages to centre the layout on each feature extent. I need to ...
2
votes
3answers
182 views

Creating a Slope Map Using Contours

I am trying to create a slope map. I have many contour elevation files. I tried to use the slope tool in Arctoolbox, but it calls for raster files and I'm working with vector data. Any help with this ...
0
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1answer
26 views

digital elevation model data help?

I know little about geographic data. I am trying to get a file of elevation data for the United Kingdom so that I can import it into a CAD program and convert it to an *.stl or *.dxf format. I ...
0
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0answers
32 views

“US NED” OnEarth JPL NASA Tiled WMS working?

I am working on developing a computer software application that displays a 3D terrain based on the 30m elevation data for USA. I am using the OnEarth JPL NASA Tiled WMS for fetching the elevation ...
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2answers
27 views

Is convention to denote Building Elevation with respect to ground or sea level?

Have a query on shapefile. I have a shapefile containing a number of polygon features representing buildings. I am trying to extract the elevation of the building. I would like to know if the usual ...
1
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2answers
80 views

Creating a DEM from CAD contour polylines

Is it at all possible generate a digital elevation model raster from CAD contour polylines with elevations? I am using straight AutoCAD 2014, not Map3D or Civil3D. I was able to bring the dxf of ...
1
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1answer
27 views

Adding shapefile elevation data to dted

I am a newbie to QGIS. Currently trying to augment a dted raster value file with vector shapefile(polygon) containing height of buildings. Have converted the shapefile into raster via rasterize ...
2
votes
1answer
95 views

Obtaining average value around polygon in raster for different cross sections?

I have elevation data in a raster, river (blue line) and the flooded area (black polygon) as shown in the image below: I want to find the water depth in the flooded area (inside the black polygon). ...
0
votes
1answer
38 views

What dem data are Flex Viewers using to create elevation profiles?

I asked a similar question a year or two ago here: Can Elevation Profile data in Arc's Flex Viewer 3.0 be exported? which appears to not have an answer. Another question regarding the Flex Viewer ...
0
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1answer
60 views

ArcGIS 10.2 Viewshed not using Z Value?

I'm currently trying to produce a line-of-sight map of a tower with no results. Every time I run the viewshed tool, the program uses the base Z value of the DEM. I use the DEM Raster for the ...
0
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0answers
35 views

QGIS - Obtain elevation profile [duplicate]

I wish to obtain a bathymetry profile along the selected path (Google Earth calls this feature "elevation profile". Can QGIS 2.2 provide this? I created a layer using the WMS service to load the ...
0
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0answers
30 views

QGIS Bathymetry Display, Bathymetry along a path [duplicate]

This post has two related questions. I am new to QGIS or any GIS software so please forgive me if the answer is obvious. I wish to view the Bathymetry point for any given coordinates (e.g. as I move ...
3
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1answer
94 views

How to obtain a DTM/DEM from DSM

I need to obtain a grid of bare ground elevation (removing all edifices, trees, roads and man-made elements) for quantitative geomorphological analysis from a high resolution (1 m) DSM obtained by ...
0
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0answers
72 views

Problem with Elevation Profile Graph

I have a problem when creating the elevation profile using 3d Analyst. I have a DEM and a polyline representing a a highway route consisting of several line segments that I have manually combined. I ...
2
votes
0answers
46 views

DTM Extraction/Smoothing in ArcGIS

I have an .las file, intended to be a DTM (bare earth) that I generated from a photogrammetry software package that has come out just a bit too lumpy. I now have the license for that software tied up ...
3
votes
1answer
125 views

Why not measure elevation from the center of the earth?

In trying to understand Geoid vs Ellipsoid height, I ran across this page. One of the claims is: Zero elevation as defined by Spain is not the same zero elevation defined by Canada ...
4
votes
2answers
98 views

How to query DEM elevation values in a web application based on cursor/click point location?

I work for a city government that has LiDAR derived DEM rasters which we would like to make accessible to other departments in the city. The problem is that many departments don't have anyone with ...
0
votes
1answer
67 views

Read Elevation from 1/3 Arc-Second NED .tif or .img

I'm trying to read multiple elevations from a USGS 1/3 arc-second IMG / GeoTIFF file. A sample of the files is available here (5 MB): http://tdds3.cr.usgs.gov/Ortho9/ned/ned_13/img/n43w108.zip I can ...
1
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1answer
34 views

Combining several rasters before r.surf.contour?

I have been trying to generate an elevation model from contour lines using first v.to.rast.attr and then r.surf.contour. Generally, it works pretty well, execpt for one issue. My data contains a lot ...
1
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1answer
44 views

Make a Ground Mask raster with the Greater Than tool (DEMs are generated from LiDAR)

I'm trying to see if I can replicate the Esri solar suitability site example from this article. I fail on the creation of the binary ground raster. I have made a Bare Earth raster from LiDAR ground ...
4
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0answers
229 views

Bringing GIS data into Minecraft

A little off the beaten path...: Denmark has built a 1m:1block Minecraft World using real GIS data. Here's the home page, in Danish: http://gst.dk/emner/frie-data/minecraft/, and an ArsTechnica ...
1
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1answer
79 views

Find minimum elevation along a polyline and return xy or point?

Using ArcGIS 10.1 and Python IDLE 2.7.2... I'm trying to find the minimum value of a polyline with a raster layer and turn that LOCATION into a point. I put everything together in model builder, but ...
3
votes
1answer
87 views

How to give elevation information to a polygon feature class using existing TIN file ? (geological mapping)

I'm an ArcGIS 10.1 user. My issue: I have a printed form of a map which depicts geological bodies being surface rock occurence. Additionaly, there are elevation contour lines. I digitized the map by ...
1
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1answer
76 views

difference of reference plane/Plane Height / Z factor in Surface volume calculation?

I have a TIN surface with Minimum elevation 25 m and Maximum elevation 140 m. I want to calculate surface volume in different elevation between 25 and 140 meter. I wonder for example If I want to ...
2
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0answers
67 views

Global height data as polygons — Natural Earth doesn't have it?

I love the bathymetry data from Natural Earth. I've been looking for the last few days for the same basic data but for land. I'm trying to find general elevation shapefiles, as polygons. I don't need ...
1
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1answer
164 views

How can I make a reference plane to measure surface volume?

I am looking to make a reference plane like the links below. I want to measure surface volume of an area in different elevation layer. I just need to know how to make the reference plane in ArcGIS ...
1
vote
2answers
208 views

How do you convert SRTM HGT elevations from WGS84 into meters above sea level?

I am building a JavaScript script that reads binary HGT files - as generated by the SRTM - and converts the data into bitmaps viewable in your browser. You can try out the script and view the source ...
0
votes
2answers
287 views

Extract ground elevation from a path of lat/lon

I have a set of Lat/Lon points and I'd like to know the actual ground elevation of these points. I have access to Global Mapper, Google Earth, AutoCAD Civil 3D. Could somebody suggest the bets way ...
0
votes
1answer
50 views

DEM difference looks like a hillshade

I wanted to find the elevation difference between 2 DEMs. When I got the data, I had to georef one image and had to aggregated it too because their cell values do not match. I also tried to resample ...
0
votes
0answers
25 views

What information, Open Attribute table of stream segment shows?

I have delineated the watershed from DEM data. I have converted the stream segment(raster) to vector lines. In the attribute table of this vector lines, there are 3 columns, CAT, VALUE, LABEL, what ...
2
votes
1answer
31 views

Wrong sorting of elevation classes QGIS

I'm a totally beginner with QGIS and maybe I have a very easy problem, but I can't help myself. I got an elevation shapefile with classes of elevations like that: 1-100m, 101-200m, ... When I try to ...
4
votes
2answers
600 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? Any advice would be ...
6
votes
5answers
325 views

Looking for (nearly) worldwide elevation data

I know the raw ASTER and SRTM datasets. Is there any error corrected version available? Or did anybody already combine the data? At least the ASTER data often misses tiles for costal regions (if there ...
3
votes
1answer
247 views

How to display an elevation profile and store the DEM elevation back to the KML line?

When I draw a track in Google Earth, for example along a road, I can right-click it to "Show elevation profile", and it displays a 2D plot of distance vs elevation. However, if I save the KML, the ...
8
votes
2answers
532 views

DEM Elevation Units

I'm fairly new to the GIS world, and have a quick question. I'm currently using 10.1. I do not know much about rasters, so does transforming a DEM from one projection to another automatically convert ...
2
votes
2answers
79 views

Elevation and point data

On arcmap 10.1, I have elevation data that is shown as contour lines (polylines) i also have point data showing the distribution on certain animals. I want to run some kind of statistical analysis to ...