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

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277 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
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0answers
55 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 ...
3
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0answers
117 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 ...
3
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588 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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180 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 ...
2
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58 views

How to show a 2.5D surface of raster above terrain layer in Cesium?

I'm developing an web application that will show surfaces of rasters and terrain. These rasters are on GeoTiff format. I learned from example cesium can show image overlays earth surface. The ...
2
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26 views

Does USGS 3DEP data use a hash or checksum?

I'm downloading some USGS 3DEP elevation data, e.g., the file at the following URL: https://www.sciencebase.gov/catalog/item/563afea8e4b0d6133fe7357b The "ID" of this file is given in both the URL ...
2
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0answers
30 views

QGIS estimate height of feature vertices from TIN

I have a TIN representing a digital terrain model, and another polygon layer representing features (e.g. building outlines) which is assumed to 'sit' on top of the DTM. How do I calculate the ...
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48 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 ...
2
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75 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 ...
2
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69 views

From track+waypoints to elevation profile with waypoints

I have a track and waypoints (1) imported in QGIS. I want to calculate the closest point from every waypoint to the track (2). Then, I want a table with data that allows me to draw an elevation ...
2
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203 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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35 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 http://www.regione.piemonte.it/geoscaweb/index.php?pgs2=0&pgs3=DTM10&...
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798 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 map....
2
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49 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
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0answers
190 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
209 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
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0answers
279 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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344 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
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0answers
210 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 ...
2
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887 views

Topography: How to convert raster into vector layers?

(nb:This project is part of the #Wikipedia #wikimaps project) 1. Question: How to create vector topographic maps from raster image ? How to convert raster topographic image into closed vector ...
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300 views

Read negative elevation data from NASA png tiles

I query NASA JPL service using query string. Response is a unsigned 16 bit per pixel png image and the values are elevation values in meters. Same is described in the capabilty xml of the layer as can ...
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53 views

How to create an elevation profile in google earth from a kml?

I have a KML file of a stream that I originally created as a line shapefile in ArcMap (one stream extracted from a larger watershed data set). I need to create an elevation profile of this stream. ...
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26 views

How to find roads with similar incline?

I have no prior GIS experience, so please bare with me. What I'm trying to do is find a road (or a portions of road) from one country that is similar to another road(or portion of a road) from a ...
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55 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 QGIS. My problem is that I don't need an air-line distance of 25 km around the points, but a "real distance" having ...
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74 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 ...
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33 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 ...
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39 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 ...
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132 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 ...
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26 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: C:\&...
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48 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 ...
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48 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 ...
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62 views

calculate Z~F from polygon and raster

I have a polygon shapefile and raster layer. How I can calculate the elevation and area (Z~F) relationship for each polygon by using QGIS or ArcMap?
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91 views

How to get the elevation of the complete sea floor?

I am not a cartographer, I am an analyst-programmer, I know nothing about SRTM, DXF, PostGIS, QGIS... I just saw those names in other questions... Is there a quick guide where I can learn about this? ...
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0answers
147 views

Modifying DEM elevation data in QGIS using a polygon

I've tried searching through the existing questions but am struggling to find a succinct answer to what I am trying to achieve. For background, I am running a flood model in TUFLOW to help support a ...
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0answers
55 views

Trajectory / ballistics

I'm trying to calculate if a canon will be able to shoot over a height in the terrain. lets saytThe canon have to be 15'000-18'000m from the target, and the impact degrees have to be over 30 degrees....
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0answers
38 views

Where can I obtain data on flood sites, land sewage systems, and property value?

I am a college student trying to obtain this data for a class project. If anyone can help that would be great. Basically, my hypothesis for this project is that land sewage systems that have not been ...
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68 views

cutting contour lines over raster (building) areas

I am looking to cut the contours in ArcMap and /or AutoCAD so they don't pass through buildings or roads. Is there a process or code to do this, so it doesn't have to be done manually? Also, looking ...
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273 views

Generate elevation profile graphs for multiple line segments in shapefile?

I'm familiar with the profile graph feature in 3D analyst and I saw the stack profile tool as well. However, I'd like to generate elevation profile graphs for 137 line segments. I don't want to ...
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261 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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158 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 ...
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47 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 ...
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67 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 ...
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0answers
304 views

How to create a buffer around a point that takes terrain elevation in account?

In QGIS, I am creating a few different buffer around points to simulate walking distances. For example, 10 minutes walk about 800m at 5km/h. Using population density, I then clip a population layer ...
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0answers
119 views

Unsplit lines based on length and attributes

I have a contour dilemma. Using Microstation, 1-ft contours have been made on a til-by-tile basis in our project. These DGNs were imported into a GDB, so the polylines have already been merged ...
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97 views

How to request elevation data from ERDAS Apollo?

I'm developing a custom application(Desktop based using uDig SDK) where user have a provision to select the line feature on map to view its elevation chart. So far I can do this using Google ...
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280 views

Can Elevation Profile data in Arc's Flex Viewer 3.0 be exported?

a related thread here: google earth profile used in mashup or flex Would like to export the elevation profile data (csv, txt, etc.) from Arc's Flex Viewer 3.0 as it creates one: Also, if there is a ...
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64 views

Process to load elevation data into Oracle 11G

We have the National Elevation data set from USGS and considering loading it into Oracle (11G) database. Can someone help with the process/steps?
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10 views

German/European standards for vertical accuracy assessment

I am working on assessing the accuracy of different elevation datasets (XYZ Grid, Lidar and a 20 years old DEM, compared to terrestrial survey Points), using the FGDC's Geospatial Positioning Accuracy ...
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31 views

Convert EGM96 gps elevation to WGS84 ellipsoid elevation.

I have GPS elevation data (300k points) in EGM96. These points are located on the East US coast. I realise i need to work out the difference between the EGM96 and WGS84 ellipsoid in this region to ...