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
82 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
votes
1answer
702 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
votes
1answer
152 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
votes
1answer
70 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
75 views

How is elevation and altitude measured?

According to my watch that claims to measure altitude, as far as I can see it says that in Stockholm Sweden the altitude is 170 meters but can that be right? How exactly can we know that 0 altitude in ...
3
votes
1answer
502 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
votes
2answers
341 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 ...
3
votes
1answer
633 views

How to get elevation with LibGeoTiff?

I'm trying to get an elevation profile from a geotif file ( downloaded from http://srtm.csi.cgiar.org/). I downloaded the libgeotiff library but i can's see any function that can return an elevation ...
3
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1answer
114 views

Help 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 I ...
3
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1answer
160 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 ...
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.
3
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0answers
146 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
619 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
votes
3answers
180 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 ...
2
votes
1answer
146 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
votes
1answer
457 views

Programmatically download (seamless) NED tiles?

I used to download 1/3 arcsecond elevation geotiffs from extract.cr.usgs.gov using web services. But a few days ago, that stopped working, probably because USGS reorganized their site. I tried ...
2
votes
1answer
114 views

How to change layer transparency without changing border lines?

I have a raster image of elevations. I have added a vector shapefile that contains local political divisions. I want to keep the elevation colors, but I want to keep the black lines representing the ...
2
votes
2answers
3k views

Can WMS be used to get a local copy of raster data?

I have tried reading up on WMS on wiki and other sources but haven't managed to get my head around a couple of points. 1) Using WMS is it possible to get a local copy of the raster data (say a tiff ...
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 ...
2
votes
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 ...
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). ...
2
votes
1answer
386 views

Orthogonal Height Profile along line (sextante -> v.segment, r.profile?)

While trying to find a way to find "valleys/ridges" within a DEM, I'd like to know if there are tools, plugins or "methods" known or available to automatically generate height profiles along a given ...
2
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1answer
200 views

How can I calculate elevation from relief?

I have an SDE Raster that displays relief, but I want to display elevation. How would I go about doing this? I would really appreciate any advice or direction on how to do this.
2
votes
2answers
441 views

How to read 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 ...
2
votes
1answer
638 views

DTED/GeoTiff layer: Get elevation under mouse pointer

I have a simple desktop app with a map control. The map data that will be available to show will be either DTED files (Military Analyst's catalog / MADTEDLayer), or GeoTiffs (created by gdal). I want ...
2
votes
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
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 ...
2
votes
1answer
159 views

Making a subsurface TIN model

I had been very glad if any of you have time to help me. I am a student and currently writing a thesis. In this paper I will create a 3D model of a glacier, where I will show the internal structures ...
2
votes
1answer
136 views

filter / generalize elevation points on the basis of some conditions

I wanted to generalize many elevation points in a rectangular area (about 700 square km). I need to take about 3 points for square km. These points must satisfy some conditions: One of these ...
2
votes
1answer
556 views

Read .DEM (USGS) FIles with C#

I have a huge number of .DEMs and have been investigating how to process them into something useful. Does anyone know how, or even if it is possible to read coordinates and elevation data from ...
2
votes
2answers
446 views

Elevation Data not showing on Globe

Using ArcGLobe I'm attempting to display elevation data. I'm using Digital Terrain Elevation Data (DTED) data and trying to load it in the following fashion. IRasterLayer rasterLayer = new ...
2
votes
0answers
6 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 ...
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
39 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 ...
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 ...
2
votes
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
vote
1answer
500 views

What is the highest obtainable resolution of FREE elevation data in the UK?

I am seeking closure with this question guys. I am aware of various sources of free elevation data ~30+ m, and I have been searching for higher resolution FREE data for a while now. This already ...
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2answers
2k views

Reading National Elevation Dataset (ArcGrid/GridFloat/IMG) with python only tools

I've found high precision elevation (1/3 - 1/9 arcsecond resolution) data from the National Elevation Dataset provided by the USGS. It comes int IMG, Arcgrid, and GridFloat formats. I know ArcGrid ...
1
vote
1answer
628 views

Help with technique to create contours from ASTER DEM in Phnom Penh, Cambodia

I have the ASTER version 2 DEM of Cambodia. I want to use it to create 1m contours of Phnom Penh, Cambodia. If anyone has this already please let me know. Now, onto the problems: I am using ArcGIS ...
1
vote
1answer
112 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 ...
1
vote
3answers
104 views

Is there demand for a higher resolution alternative to GPS tracking in the GIS market?

If there was an alternative to GPS that provided higher resolution tracking, what applications would there be for it in GIS? Note that this means higher resolution, but not necessarily higher ...
1
vote
1answer
250 views

Buffer analysis - use of surface area based on DEM

I have one problem and this is that I would like to create a buffer around point. This is simple with ArcMap using the buffer tool. But is it possible to create the buffer considering also the true ...
1
vote
1answer
185 views

How to apply DEM elevation adjustment parameters?

I have a nice DEM, created from UAV data, which I want to process further in QGIS, my platform of first choice. In order to represent the evelation of each pixel correctly, I have to adjust the ...
1
vote
2answers
2k 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 ...
1
vote
1answer
420 views

Using SRTM data, how to get the coordinates of the peaks visible from a location?

Using SRTM data and a coordinate-altitude database of the peaks, I want to get the coordinates of the visible peaks from my location. I want to make an application similar to this. How is this ...
1
vote
2answers
680 views

Calculating slope over distance from raster

I am sitting with an elevation raster, trying to produce a calculation for slope angle. I have a cell size of 2,-2 and I am trying to figure out how to calculate cell value difference between adjacent ...
1
vote
1answer
94 views

Read height data from Meridian 2

I'm having difficulties reading the Gridded height data (OS Meridian 2). I'm loading with OSGB 1936 reference system but have trouble finding the lat/lon data for each point. i.e.I open the attribute ...
1
vote
2answers
670 views

Mosaicing LIDAR files in ArcGIS 10

I have a number of LIDAR files (the extension is .adf). When put together, they show the same area (each shows one part of it), so, before I do anything else with them, I would like to combine them ...
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vote
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
vote
1answer
591 views

How to Create Cost Surface Raster for Least Cost Path Analysis?

I have a DEM raster and would like to carry out a cost path analysis. Among other factors such as slope, proximity rivers etc. I would also like to take elevation into consideration. According to ...