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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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65 views

Snowline extract elevation using NDSI index in Google Earth Engine

I'm trying to extract snowline elevation values using the NDSI index (normalized difference snow index), with the target of to know the variations of height over Landsat collection. I'm trying to do ...
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24 views

How can I change the elevation of a lake on a DEM so I show the lake bottom contours?

I'm studying the drainage of a lake and I have a DEM of the lake and the surrounding area. I already identified the shorelines of ancient lake levels at higher elevations, but I would like to keep ...
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1answer
64 views

QGIS: Edit elevation in DTM to get correct slope of a river

I am new to QGIS and just need it to do a hydrolocic analysis of an area of which I later make a flow model with HEC-RAS 2D. I made it according to this tutorial: https://www.youtube.com/watch?v=Ro-...
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0answers
33 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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32 views

Band 1: Access window out of range in RasterIO()

I'm trying to implement a mouse_move event handler to display the elevation based on the mouse location. I'm using the ThinkGeo API to display the raster map (.tif) and gdal C# to get the elevation ...
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0answers
17 views

Summarize Elevation in ArcGIS Pro not working? [closed]

The tool Summarize Elevation is not producing the typical fields ie Min, Mean, and Max elevation field values, although fields like Dem Res, Product Name, Source, Source URL are being produced. Has ...
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1answer
54 views

Converting RTK Elevation Data to DEM?

I have a shapefile that contains elevation data. I want to eventually convert this to a slope layer. I'm assuming I have to convert to a raster, then a DEM, then slope. Is that correct? If so, ...
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2answers
69 views

How to extract Z data from a shapefile from points on another separate layer QGIS

I have two layers; one with elevation data (m), and the other with roads (derived from points via points to polyines). I want to run a spatial query that basically extracts the elevation data from the ...
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21 views

Command line to change altimetric reference with gdal

I want to convert a DEM with the following GEOGCS : GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]], AUTHORITY["EPSG","6326"]], ...
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2answers
29 views

Obtaining Elevation for single point from ArcGIS REST API?

I have spent quite a while trying to get the ESRI API working. Basically we would like to pass a lat, long to a service and obtain the elevation back. Our previous service stopped working - we were ...
2
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1answer
59 views

How can I modify DEM elevation data within QGIS using a polygon?

How can I modify an existing DEM using a polygon? I have a DEM raster with terrain varying between 355 and 365 meters. I have a polygon I've drawn over the area. Ideally, I would like to uniformly ...
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39 views

Is there a way to linear reference a line in QGis [duplicate]

Iv'e seen a number of plugin's that do things like create grids of points and such like, but what I need to do ideally is to create a line of points that follows a line geometry, and then drop those ...
2
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1answer
51 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 ...
1
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1answer
37 views

Calculating meshes average within boundary?

I have mesh data of elevations. Each mesh has a value of elevation (e.g. 87, 60, 33, ...). And I also have data of administrative boundaries. I want to calculate the average of each administrative ...
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1answer
43 views

How can I show the roads that are below 10 ft elevations?

I have point elevation data and road layers for a region. I am trying to show the road sections that are below 10 ft elevations. How can i solve such problems with elevations? I am using ArcGIS 10.3.1....
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1answer
70 views

Reconciling elevation difference between SRTM and old US Army map in Laos?

In QGIS I georeferenced a 1970 US Army contour map for part of southern Laos (20 m intervals) with the following indicated properties: Horizontal datum Indian datum 1960 Spheroid=Everest Verical ...
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1answer
41 views

Determining elevation of a point from a DEM in QGIS?

I have created a series of DEMs that layercake on top of each other. I would like to be able to lookup a coordinate and get the elevation that has already been interpolated. The goal is to ...
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2answers
113 views

Source of Contour Lines for QGIS

I am planning to go on multiple days hike and used Wikiloc to download GPX tracks. We will use a GPS for our navigation but I always want a printed map as a backup. Maps for that area are notoriously ...
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1answer
55 views

Using UK Government Data in QGIS?

I've downloaded some .asc files from the UK Government. They are 1m resolution LIDAR tiles. Apparently. When I load them into QGIS, they appear with the nice thumbnails and everything. But I get ...
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0answers
46 views

Extracting raster values to point feature class failing in ArcMap?

I need to extract values to point features from Mosaic dataset made out of DEMs (Whole world SRTM) . My feature class has 18,000,00 points. When I ran the below tools, only <20K points receive ...
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0answers
40 views

QGIS - how to extract interpolated elevation from a raster? [duplicate]

I maintain my own database of oil well information with thousands of curated points. I have lat, long, and subsea elevation. This information was used to create a raster and a set of contour lines. ...
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1answer
141 views

Getting correct elevation from hgt file [closed]

When reading SRTM3 data from a .hgt file I get the wrong elevation of a specific latitude longitude and I can't see why. Maybe someone can see the problem ? My coordinate is near Lissabon in the sea ...
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2answers
42 views

DEM's from Baja, Mexico [closed]

I need to extend my digital elevation map (10m or 30m will do) into Baja from southern CA.
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2answers
295 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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1answer
35 views

Identifying the greatest value point within each polygon

I have a series of polygons (4,000) and a series of points that exist on the perimeter of each polygon (3 to 5). The points refer to the elevation value which has previously been extracted from a DEM ...
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2answers
57 views

Elevation Data in form of a database or colored Map

I am new to the GIS Topic and I hope someone can help me in the following. I am looking for elevation data for the whole world in the form of a database (Latitude; Longitude; Elevation(Level over ...
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0answers
85 views

QGIS - Lookup elevation or slope from geoTIFF from a series of lat/lon values

I have a geoTIFF file (pretty large) covering a good chunk of Spain around Almeria. I got it from the EU-DEM v1.1 data (25m resolution), freely available in which I have a route in lat/long and I want ...
3
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2answers
263 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 <...
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2answers
51 views

Editing elevation in ArcGIS Desktop?

I have a raster layer that covers a large area (three cities). When I load the raster layer into a 3D visualizer, there are multiple areas with a drastic change in the slope rather than a gentle ...
2
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1answer
66 views

How do I use a Simple Feature Collection (sfc) from the sf package with the elevatr package to load elevation data?

I'm trying to load elevation data from AWS using the elevatr package, with a region defined as a Simple Features Collection from the sf package. Here's a simple example: library(elevatr) library(sf) ...
11
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3answers
236 views

Latitude above and below the surface of the Earth

I know that Geodetic Latitude is measured with respect to the normal at a point on the surface of the reference ellipsoid. But what about points above and below the surface? Do they follow a ...
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133 views

Is there a “vincenty” version for calculating the elevation between two points?

As many of you know Vincenty is a great tool for calculating the azimuth (e.g. bearing) between two points with reference to True North. Currently, I have a python script that takes two coordinates in ...
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52 views

How to interpolate ibutton transect temperature data ArcGIS

I have three transects on opposing slopes. Each transect has ibutton data loggers set to record temperature at hourly intervals. The loggers are spaced at 20m altitudinal intervals from 1550 - 1810m (...
2
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1answer
129 views

Reprojecting XYZ coordinates in Python whilst keeping Z coordinate constant

When doing a reprojection from a projected coordinate system (e.g. EPSG:28992) to a geographic coordinate system (e.g. EPSG:4326), the Z coordinate gets an offset of 45 meters. The Z coordinates of ...
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1answer
81 views

Elevation API: Same coordinates, different elevation result

I'm using google maps elevation API, but while asking a single request(single coordinates) and a multi-request(many coordinates), I'm getting different elevation result of the same latitude and ...
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2answers
52 views

Expression in field calculator to populate a field with the same attributes as other field

I am just after a super simple expression to copy the attributes of one field directly into a new field with a different name - to export to AutoCAD with Z height data.
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1answer
61 views

Can QGIS produce a Stage Storage Plan?

I work for an engineering firm, and my question to the forum is: Can QGIS produce a stage storage plan for multiple drainage basins? I am attaching an image of what I am talking about. Currently, we ...
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0answers
52 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
43 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
49 views

Locate roads that are close to steep slopes which risks landslides

I've a query, I'm trying to locate all the roads which are basically at risk of erosion (landslide?) when it's raining heavily for a municipality. What I have to work with is this: A shape layer ...
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1answer
110 views

Getting elevation from polyline feature using QGIS?

I have imported contour lines from AutoCAD DXF file. I've 3D geometry. Í would like to add a new column to the attribute table of the contour lines. In th field calculator I user the following ...
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1answer
537 views

Creating Elevation Profile from Line Shapefile of Contours using QGIS?

I have a line shapefile that contains contour lines. The attribute table of the shapefile has a field that gives the elevation of each line. I would like to draw a line across the contours and get an ...
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1answer
70 views

Elevation shading of linear feature compared to surrounding ground level in QGIS

I have a digital elevation model (DEM - geoTIFF) in QGIS 3.2. There is a linear feature (earth bund/wall) in the DEM that I would like to shade/colour based on its elevation above the surrounding ...
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0answers
93 views

Generate XYZ coordinates of DEM mesh/grid

Is there a way to generate a wire grid of plain text XYZ coordinates starting and ending points for each wire segment? I want to generate them from a digital elevation model. Preferably with gdal/qgis ...
2
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0answers
102 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
37 views

GeoTIFF software generation

I have some data about the height of a set of points (for example, from the Google Elevation API). There is a task to save this data in GeoTIFF format, then to use in osgEarth (GDAL). How can this be ...
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0answers
27 views

Why isn't variation in elevation across DEMs of different resolutions reflected in the profile graph? [duplicate]

In ArcGIS; Spatial Analyst. I have a DEM at various resolutions: 1m, 3m, 5m, 10m, and 30 meters. In Spatial Analyst I have interpolated the same 1km line across the each of the DEMs, expecting to get ...
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1answer
85 views

Trimble 7X GNSS point Z returns negative elevations

I have a newly acquired Trimble 7X (with a centimeter kit). I collected a point in an area with a clear view of the sky. The accuracy indicator showed 1" accuracy and post processing and a ...
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0answers
112 views

Elevation Point Data from Google Earth to DXF Contours with height separation?

I've taken point data through a KML file converted to CSV into QGIS, which has given points that I then used the Contour plug in to give lines. I wish to export these contour lines with elevation data ...
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0answers
43 views

QGIS .adf file saved as GTiff changes elevations

I have got two .adf DEMs which I need in GTiff format so they can be merged. When I 'Save As' the layer as a GTiff, the resulting output has elevations which are inconsistent with the original .adf ...