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

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1answer
52 views

How to update the Z value using an UpdateCursor?

I have created the following script to mimic the ArcGIS 3D Analyst tool, FeatureTo3DByAttribute, which creates a 3D copy of a 2D feature class and sets the Z to a specified attribute. import arcpy, ...
1
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0answers
27 views

How to show elevation on mouse hover in QGIS?

I've got a DEM layer and would like to have the status panel in the bottom display the elevation in addition to the mouse coordinate. Can that be done? Using QGIS 2.6.1
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0answers
12 views

How to calculate the Vertical Distance to Channel Network in ArcGis?

In Saga there is the tool "Vertical Distance to Channel Network". Is there a way to produce the same data in ArcGIs? With con("flowacc" > xx, 1) I was able to create the Channel Network. I am ...
2
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0answers
16 views

Generate contour lines for big DEMs and import into PostGis

I've downloaded the SRTM DEM files for most of Europe, from both 3arc_v4.1 and 1arc_v3 versions. The first comes in 5x5 degrees tiles, the latter in 1x1. I can stitch them together with gdalbuildvrt ...
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1answer
38 views

Displaying DEM with real elevation values in ArcGIS Desktop?

I am trying to create a DEM with hillshading map in ArcGIS Desktop 10, but I'm getting the result with scale values between 0 and 254. How can I display the scale with the real elevation values? ...
1
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1answer
26 views

Changing the Axis on a Profile Graph

I'm working on a map with forest trails and I want to get an elevation profile of them all individually. I have gone through and interpolated the trail layer with a DEM so that I can use the 3D ...
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2answers
40 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
37 views

How to obtain elevation value from given SRTM data on mouse click in web browser?

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 ...
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1answer
30 views

How to decrease elevation values of DEM using open source GIS sotware? [closed]

I am newbie in QGIS, but I was wondering how to decrease elevation dem DEM using QGIS? Can QGIS do that? Or anyone of you can tell me any open source GIS software to perform that?
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0answers
18 views

Where can I download 1/9 arc-second elevation data for the Hawaiian islands?

In same spirit as this question, I'd like to know where I can find 1/9 arc-second elevation data for the Hawaiian islands. The USGS national viewer provides 1/9 arc-second data for certain places, ...
4
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1answer
102 views

Identifying south facing mountain land, above an elevation, within a slope range, less than fixed distance from major roadways

This odd question comes from believing that such an analysis is plausible in a GIS system. Only, I don't how to accomplish the various discrete steps implied from the Title, nor where to get a topo ...
3
votes
1answer
113 views

How to subtract out the slope (in general) of a DEM?

I'm searching for a solution process to subtract out the slope of a DEM like this: I have a high resolution DEM and want to reconstruct historical/old/not active parts of a river. The problem is ...
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1answer
28 views

Want to intersect a polygon of a certain elevation with a tin surface

so I want to generate a flood plain for a river in ArcMap. Basically this means that I want to create polygons with certain elevations above the drainage point elevation (870 m). For instance I would ...
0
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1answer
30 views

Web site to show GPX with elevation?

I notice that a GPX file contains not only lat + lon but also elevations: <trk> <name>Some route</name> <trkseg> <trkpt lat="50.64536" lon="3.05657"> ...
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1answer
51 views

How to get the z(elevation) value from a rendered map at webgl(Qgis2threejs plug-in)?

I am interested at getting the z value at any lat and long i want. For example i have made a 3D map using Qgis2threejs plug-in and it showed the map rendered using three.js library. The elevation ...
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1answer
66 views

Learning about bathymetry?

Besides reading about bathymetry, I would like to work on some hands-on training that I can learn about bathymetry. Is there any good bathymetry out there that I can get some training with the ...
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0answers
17 views

QGIS Extract elevation data only for one country [duplicate]

Hye, Here a map built with (1) a shape file for country contour, and (2) raster from .hgt files with altitudinal representation. How can I only select the area corresponding to the country ? I found ...
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0answers
37 views

River flow downhill

I have polylines (rivers) with assigned elevations. I need to ensure they are flowing downstream and indicate which vertices are incorrect. I do not have 3D analyst, spatial analyst, or network ...
6
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1answer
93 views

What resampling technique should be used to reproject an altitude raster?

Does anyone know whether I should choose: nearest, bilinear, cubic or majority when projecting the WorldClim altitude raster layer?
2
votes
2answers
70 views

Check if a polygon is at one elevation

I have a polygon (pond) and I need to ensure it is at one elevation. I have converted all vertices of the polygon to points, used summary statistics to determine the range in elevations and if the ...
1
vote
1answer
54 views

Select points with lowest elevations and same x,y coordinates

The problem is as following, I have a point layer with x,y,z coordinates. Some of the points have same x,y but different z. I need to separate points without duplicates (x,y) and in case there are ...
3
votes
2answers
75 views

How do I get rid of this thin band between raster layers created from TNM?

After hitting my head against the table for many days, I'm humbly presenting myself to the QGIS community. I downloaded 4 IMG files (1/3 arc second, elevation data) from The National Map on the USGS ...
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2answers
64 views

Interpolate dxf polyline vertex elevation from DTM?

I am working on several autocad polylines (with several vertices...) that have the exact N,E coords but now I would like to add the elevation data for every polyline's vertices from a dtm. I thought ...
2
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0answers
29 views

infer the altitude from a DTM & finally provide it to point / evincere la altitudine da un DTM & finalmente fornirla a dei punti

I would like to complete a point vector's table with Z data. I am not able to take Z coordinate from a dtm (downloaded from ...
2
votes
1answer
28 views

Looking for smallish raster of global elevation data

I'm trying to find elevation data for the whole globe for a simple mapping application and I'm not having any luck. I really don't want anything fancy, just something like a 4000x2000 raster of ...
2
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0answers
90 views

Command line tools to generate elevation profile from DEM + GPX/GeoJSON

I'm looking to generate elevation profiles from a number of GPX traces (which I also have GeoJSON conversions of). I have 20m resolution DEMs of the area, in GeoTIFF format. Ultimately I want to ...
3
votes
0answers
25 views

How can ASTER elevation data be converted to a CAD model

I am trying to convert ASTER elevation data to a 3D CAD model using only opensource software. I have tried using different file formats but I have been unsuccessful. I use QGIS for my GIS work and ...
4
votes
1answer
168 views

Creating a point corresponding to the maximum elevation of a DEM [duplicate]

I am wondering how can I create a point corresponding to the maximum elevation value of a DEM. I mean, from the DEM I can easily get the maximum elevation. For the sake of a viewshed analysis, I would ...
2
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0answers
61 views

Find Average Elevation - ArcGIS Desktop

I am working with 2 shapefiles. One contains the boundaries of a city, the other contains polylines representing the topographic features of the area. Essentially, the polylines make a topographic ...
2
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0answers
32 views

Project lines onto surface in QGIS

This question may already be answered so please point me in the right direction. I am designing a water distribution system for a rural village in Guatemala. I have created contours for the area. I ...
2
votes
1answer
22 views

Grass, Route Finding with Elevation Limits

I've got GRASS (7.0) installed and I "play" with it on ocassion since I am far from a GIS pro. What I want to do is to find all road routes from a certain point limited by distance (path length, not ...
3
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0answers
59 views

Where do I find official summit elevations found on USGS topo maps?

I'm creating topo maps for my day hikes guides for national parks. I've already done one for Glacier National Park. When I was working on summits, I downloaded the data for Montana from GNIS and when ...
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0answers
52 views

Inverting color ramp in legend

I have inverted the color ramp to display land surface elevation, now when I add a legend in print composer it shows the lowest value at the top and the highest at the bottom. See below: It is more ...
2
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1answer
85 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 ...
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0answers
19 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
50 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
votes
0answers
392 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
votes
2answers
125 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
votes
1answer
133 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
74 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
votes
0answers
92 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
210 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 ...
4
votes
1answer
618 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 ...
1
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1answer
131 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
338 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
216 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. ...
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0answers
100 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 ...
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4answers
148 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
878 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
39 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 ...