Questions tagged [elevation]

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

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1k views

Reading elevation data from WMS response?

I am trying to get elevation data from the tile received from USGS server. I query the data using Image Format image/Png. When I read the data I get color values. I need to know how to read the ...
3
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1answer
85 views

Generating a buffer of a vector line based on raster values where the vector intersects a raster

I am trying to figure out how to buffer a vector shapefile with a variable distance (in QGIS). However, the variable distance needs to be dependent on the value of a raster (DEM) where that vector ...
3
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3answers
822 views

How to quickly download all GMTED2010 data?

Is there a way to automatically download all the tiles in GMTED2010 data? From: https://topotools.cr.usgs.gov/GMTED_viewer/viewer.htm I can only seem to be able to download by double-clicking tile ...
3
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2answers
69 views

Selecting based on distance and change in elevation

I am trying to find areas near a series of roads that are withing 500 ft of the road, and have a change in elevation of +50 ft. I have been provided a 2 ft contour of the area, and a centerline layer ...
3
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1answer
2k 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?
3
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3answers
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Obtain all elevations points from a raster DEM

I need to obtain all elevation grid points from a raster DEM. I see the steps required as: Read in raster DEM (Arc Info Binary Grid format). Create subset area using Points2One (see triangle area ...
3
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2answers
6k views

extract elevation values along a line using Google Elevation API

I note that there is the Google Elevation API. I see they have an example at the bottom showing an elevation profile for a line. Is there a premade service someone has put up on a website for me to ...
3
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2answers
571 views

Plotting and analyzing extracted elevation data in R?

I have a shapefile of county boundaries for New York state and elevation data downloaded through the elevatr package. library(elevatr) library(raster) library(sf) library(USAboundaries) counties <...
3
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1answer
170 views

Extracting only elevation data from NASA's GLAS Satellite LiDAR to create raster DEM?

I'm trying to open data downloaded from NASA's Earthdata site in ArcGIS 10.4.1. Specifically I'm trying to open "GLAS/ICESat L2 Global Land Surface Altimetry Data (HDF5) V034" (Image below, ...
3
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1answer
107 views

Assigning elevation to reclassified raster in ArcScene or ArcMap

How it it possible to make a 3D view of reclassifed raster map in ArcScene or ArcMap? I have identified a potenial avalanche area using DEM in ArcMap and now I want to have this map in a 3D view in ...
3
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1answer
121 views

What function should I use to assess the degree of elevational change (rocky cliffs etc.) of a DEM?

I have a DEM of my research area and I want to assess how the topography/elevation changes. I am specifically looking to see what areas may be good suitable bat-roosting habitat so I am trying to ...
3
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1answer
38 views

How do I bring the Z value to attribute table?

I have a shapefile exported from a hydraulics software that I use. The file is exported as polylines. I convert it to a point layer using the "Extract Nodes" function. The remaining piece of ...
3
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1answer
49 views

Copy elevation from points to line

I have a vector line, but it has no z-dimension. I have some points along the line, which have the elevation included. Can I add the elevation from the points to the line at that specific point? ...
3
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1answer
247 views

Elevation profile from existing lines

I am trying to pass the geometry of a polyline from a map service layer to the elevation profile widget. Normally, when using a polyline generated from the Draw tool, we can grab the event geometry ...
3
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1answer
223 views

OSM Perspective View for Android/iOS

I am recently working on a project where i want to show a skiarea in a perspective view, like you know it from maps of skiresorts where the ski lifts are displayed. Are there any libraries where i can ...
3
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1answer
178 views

Convert DEM elevation points from centimeters to meters

I would like to convert a large DEM stored in PostGIS which contains elevation values in centimeters to elevation in meters. I found an easy way by updating each point like this: UPDATE mydem a SET ...
3
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1answer
295 views

Counting pixels on raster image

I have a raster file that show forest cover, very simple, where there is a green pixel there is forest. I need to count how many of this pixels fall under a certain elevation. I have the elevation ...
3
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1answer
256 views

Elevation profile using linear shape in ArcGIS Desktop?

I'm working with ArcMap 10.2. So, it's not a duplicate of "Displaying elevation profile and storing DEM elevation back to KML line using QGIS?". I have a linear shapefile that has only one element (a ...
3
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2answers
106 views

Exporting grid line nodes with ELEV attributes as data frame? [closed]

I would like to have a data frame of nrow x ncol where nrow = rows of my grid lines and ncol = col of my grid lines. The purpose is to use the ELEV data for 3D topography modeling in R. This is what ...
3
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2answers
766 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 ...
3
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2answers
98 views

Making simple line more complex using QGIS? [closed]

I am trying to make my own version of code to generate elevation profile for a line drawn over a DEM and I got stuck very early on. As a simple use case: I have a line that consists of just two ...
3
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1answer
969 views

Performing viewshed analysis with Dutch AHN files in QGIS?

i downloaded the new (dutch hight data) AHN files, and was trying to perform a viewshed analysis at some point near UTRECHT. The plugin (grass plugin) works ok, i tried it before with a dem map. ...
3
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1answer
6k views

How to convert to Australian Height Datum from Google Earth elevation?

I am trying to figure out how to convert from Google Earth elevation to Australian Height Datum (AHD). Google Earth's elevation / altitude is based on The vertical component (altitude) is measured ...
3
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2answers
2k views

Add Surface Information in 3d-analyst

One of our guys is using the "Functional Surface->Add Surface Information" feature in 3D-analyst tool in ArcMap 10.1 to add elevation data to an XY list. It's the only feature we're using from the 3D-...
3
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1answer
182 views

Corpscon6 reliability

I've been blindly using Corpscon to convert from NGVD29 to NAVD88. Have any of you kind folks found issues with your outputs?
3
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1answer
153 views

Show elevation profile from linestring's z values

I have linestring geometries with z values and I want to display them in a nice elevation profile (with x/z scaling functions, several profiles to overlay, and so on). Is there any QGIS function or ...
3
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1answer
92 views

Including elevation values in polyline (to export it as ASCII table)?

I'm using a code to simulate flood events and I need to build two main files: one with the river channel width and another one with the bed elevation (both in ARC-info ascii raster format). I've ...
3
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1answer
281 views

Postgis Self-intersection on geometry<->raster comparison

I am rather new to postgis and try to get a (weighted) average height of an area around a point. I am running Postgresql 9.5.5 with Postgis 2.2.1 on Ubuntu. I have imported ASTER GDEM elevation ...
3
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2answers
153 views

GeoTiff Elevation Service

Is there a standardized web feature (WFS) or web processing query to get a single pixel value from a map? I don't need a whole tile, which seems to be what the WFS and WMS standards are designed for....
3
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1answer
695 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
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2answers
519 views

Find elevation for series of (lat,lon) combinations to make 3d model of earth with relief

I would like to say I am a complete novice to the world of GIS, so if I ask stupid questions or make strange assumptions, please point it out and I will try to clarify myself. I would like to make a ...
3
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2answers
308 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 ...
3
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1answer
2k views

Extracting elevation data using 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.
3
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2answers
2k 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 ...
3
votes
1answer
135 views

Elevation off Road in ArcGIS/Python

i'm using the Modelbuilder in ArcGIS 10.1 to calculate pixels depending on their slope and distance from the road. The third necessary task is to find out, if the pixel is upwards the road or ...
3
votes
1answer
2k views

How can I get the elevation of a point in openlayers?

I want to know if it is possible to obtain the elevation of a point with some type of control of others. I am painting a linestring with a series of coordinates but I need to know the elevation of ...
3
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2answers
255 views

Obtaining nodata information for ASTER datasets?

Is there any way to determine what the nodata value should be, in a set of geotiff images that do not have the 42113 tiff tag ? I am trying to get elevation information, programatically in c++, and ...
3
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1answer
304 views

Change ellipsoid reference for altitude in a DEM

I have DEM data stored as RGF93 (Lambert-93) for lat/lon and NGF-IGN69 for altitude. I'm trying to change the reference ellipsoid for the elevation data (ultimately to NTF, but WGS84 would be fine to ...
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0answers
51 views

Checking and enforcing downstream Z constraint for synthetic streams?

Assume I've delineated planar (X, Y) stream breaklines to use them for enforcement of bare ground DEM derivation from high density lidar data. The stream features are in a Z and M enabled polyline ...
3
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0answers
160 views

Which STRM resolution Srtm2Osm.exe uses?

The piece of program Srtm2Osm uses SRTM elevation model from NASA to produce countour lines in OSM format. Does it use the SRTM1 at 30m or SRTM3 at 90m?
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0answers
81 views

How can ASTER elevation data be converted to a CAD model? [duplicate]

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 ...
3
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0answers
225 views

Elevation statistics for a given Area

I am attempting to determine the best way to calculate the Minimum and Maximum elevation for a defined area. The area is defined by an IPolygon The elevation is defined as an ISurface Possible ...
3
votes
1answer
1k views

How can I programmatically project the Z value of a z-aware feature point, using ArcObjects in .NET/C#?

I discovered the following code leaves the Z coordinate of featurePt untouched: // if not WGS84 project it if (!SpatialRefsEqual(featureSpatialRef, srWgs84)) { // featurePt here is a Z-Aware ...
2
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1answer
6k views

How to conditionnally assign a new value to pixels of a raster image?

Given a topographic GIS raster of one country crop.tif: Given a know pixel value such as elevation (z) is +73 : $ gdallocationinfo crop.tif 1 1 -valonly > 73 Given an elevation threshold n = 50 (...
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2answers
308 views

Calculate pixel value in arcmap

I want to change pixel values of elevation data. I want to change values meter to feet. So i need to multiply pixel values with 3.2808. How can i do that in arcmap?
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5answers
11k views

Creating Slope Map Using Contours in ArcGIS Desktop?

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.
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1answer
2k views

Querying Elevation Data in Postgis

Problem: I have a bunch of raster data (DTED) and I want to use this to make elevation queries using PostGIS (if it makes sense). E.g. I want to ask the question "what is the elevation at (lat1,lon1), ...
2
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1answer
564 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
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1answer
220 views

Lidar Elevations Data

I am trying to acquire a method of detecting sub cm elevation without manually measuring from the field. Can LIDAR data produce this for me? Example: A 1500 foot long pipe conveying water from one ...
2
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3answers
3k views

Seeking alternative to Google Maps Elevation API?

The Google Maps Elevation API lets me pass a URL like https://maps.googleapis.com/maps/api/elevation/json?locations=39.7391536,-104.984703 along with a developer key, and get a result like { "...