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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1answer
442 views

Setting elevation data for tie points in Pix4D

I am currently working in Pix4D and am trying to assign elevation data to my selected tie points. I have aerial images taken using a camera with GPS from an aircraft and am working with a fairly ...
2
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1answer
412 views

Adding elevation data to a network dataset

I am trying to add elevation data to my road network to more accurately calculate walking distance to and from schools. I have figured out how to do the network with out elevation, but for the life of ...
2
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1answer
461 views

How to make slope map from elevation map in Lat/Long?

I have an elevation raster map of the world, in Lat/Long. When I make a slope map, the results of the raster cells will be either 0, or values close to 90. The problem seems to be that the Slope ...
2
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1answer
117 views

Calculating ground cover along a path

I'm trying to figure out an efficient way of pulling data about ground cover along a specific path, where I know the starting lat/long and the end lat/long. I've found that the USGS has ground cover ...
2
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1answer
106 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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1answer
70 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 ...
2
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1answer
913 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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1answer
551 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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2answers
3k 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 ...
2
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1answer
86 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
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1answer
2k 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 ...
2
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1answer
175 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 ...
2
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1answer
2k views

How do I add elevation data to a GeoJSON line from a GPX file?

I understand that elevation can be added as an optional third value in Coordinates (lat, long, elev) in a geojson file, but I can't find a way to actually do that from a gpx file. I've used ogr2ogr to ...
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1answer
656 views

Python GDAL: find out spikes and pits in DEM

I'm working with on a DEM (Geotiff) in Python GDAL, and I'd like to find out the spikes or pits in my terrain. I have no idea how to proceed, does anyone have good algorithm to help me out? Thanks, eo
2
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1answer
409 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
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1answer
318 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
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1answer
979 views

How to create a profile with profile points at discrete altitude intervalls, e.g. each 10 m

In both SAGA and QGIS theres a profile-from-line-function that does a nice job of creating profiles. But there's no way to control the altitude spacing. Any ideas for workflows that would allow me ...
2
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1answer
1k 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
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2answers
628 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 ...
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0answers
19 views

HGT Elevation vs Calculated Elevation

I wondering how to interpret the elevation calculation. Per example. We are in Canada and I use SRTM3 files. I use the GDAL library to extract my elevation, everyting is ok, except: Why (or how) the ...
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0answers
47 views

Route creation with specific length and elevation change [closed]

I'm currently working on a project for my computer science study. The goal is to make a service that allows the user to enter a distance and elevation change which will then result in a random route (...
2
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0answers
51 views

Converting .gri to topojson

I am making client-end javascript-powered maps in the context of web development. I am not using gdal, which I gather is a special kind of rendering software. Data source site: http://www.diva-gis....
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81 views

Complex 3D/elevation profiles in ArcMap 10.6

I'm looking to create a more informative 3D Profile than appears possible with vanilla Arc tools. Honestly I'm kinda surprised that this doesn't exist, maybe I'm searching the wrong terms. Situation: ...
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0answers
76 views

Selecting raster pixels based on dem range

I have two raster layers that are equal extent and resolution: one that is qualified as nonforest tree cover that is made up of pixels with either the value of 1 or NA, and one DEM. What I am hoping ...
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0answers
55 views

Converting Surface Model to Elevation Model?

Is there a way to convert a digital surface model (DSM) to a digital elevation model (DEM) in QGIS? Surface models contain lots of noise (e.g. trees, buildings) when I only want to show the ground. ...
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0answers
206 views

How to change the vertical datum of a geotiff DEM

I am trying to do some change detection between SFM derived DEM products, but the DEM i would like to use as my base elevation (and one other) is in NAD83, the remainder are WGS84. I would like to ...
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0answers
197 views

GDAL merge of DEM data resulting in large black tiles, elevation min/max problem?

I am new to QGIS (former Arc user) and having trouble with the raster merge tool. I am merging 7 tiles of SRTM arc 1 data to cover a province in eastern Ecuador. Data is resulting in large areas of ...
2
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1answer
189 views

Georeferencing X Y (AND Z) with GCPs in QGIS

I have GCPs recorded to centimeter precision in lat, long, and elevation. I want to georeference my UAV-photogrammetry-generated GeoTIFF and DEM with these GCPs (since the GPS on my UAV is only ...
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0answers
76 views

Align approximately colocated vector points for comparison

I have a more general, methodological question and do not have much knowledge about GIS techniques. I have 6 topographic survey ([x,y,z] point clouds), each representing the same dune/beach system ...
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0answers
727 views

Correcting incorrect altitudes of points recorded by my Android or how to calculate Geoid Height in QGIS

I tried to edit my question with more details and I also think that lot of people can benefit from this question! I was recording a track with my Android and later I found out that I end up having ...
2
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0answers
525 views

How to calculate elevation of the point?

I have two points: A ( x1 ( latitude ), y1 ( longitude ), z1 ( elevation ) ) and B ( x2, y2, z2 ). x1,y1,z1 and x2,y2 are known, also I know the distance between A and B. How can I calculate z2 ...
2
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1answer
64 views

Elevation profile and chemical concentrations

I have a IDW layer showing the pattern of a chemical concentration. I have also created an elevation profile across the same area. Is there any way to include the IDW measurements with my elevation ...
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0answers
271 views

DSM and buildings height

How can I create a Digital Surface Model in order to collect the height of buildings and what's exactly needed to create a Digital Surface Model? Any software provide creating it (ENVI or PCI ...
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0answers
132 views

Is elevation MCDA possible in QGIS? [closed]

Taking into account topology and existing building heights, would it be possible to do a MCDA and examine where densifying through new construction would be most profitable*, assuming that new ...
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0answers
330 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 ...
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0answers
46 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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1answer
399 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 ...
2
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0answers
183 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 ...
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0answers
166 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 ...
2
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0answers
372 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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0answers
310 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 ...
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0answers
533 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 ...
2
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2answers
319 views

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

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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0answers
48 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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0answers
3k 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....
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0answers
87 views

Projecting lines onto surface in QGIS? [closed]

I am designing a water distribution system for a rural village in Guatemala. I have created contours for the area. I need to lay out the pipe routes and need to know how to get the elevation of the ...
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0answers
214 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 ...
2
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0answers
249 views

Gridding or interpolating elevation data? [duplicate]

I wonder if someone can recommend a 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 second. ...
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0answers
1k 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
452 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 ...