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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161 views

How to correct the elevation of the raster?

While comparing the DEMs of relatively small area raster (1) obtained of UAV data and (2) EU-DEM elevation model, I spotted around 30 meter difference in elevation between them. Since no GCP was ...
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2answers
415 views

QGIS - Calculate Highest Elevation within 1 degree grid

I have downloaded country raster elevation data from Diva-GIS and added 1 degree grid from "View >> Decorations >> Grid" as seen in the image below. Now, I want to know the highest elevation within ...
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1answer
187 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
489 views

Calculating slope and aspect from DTM lidar elevation data in ArcGIS Desktop? [closed]

I have an ASCII 2m lidar DTM file which I converted into a raster in ArcGIS with the From ASCII to Raster tool. From this DTM file I would like to calculate the slope and aspect. I have used the ...
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420 views

Converting elevation from EU-DEM (ETRS89) to WGS84

I'm having a hard time trying to use elevation data from EU-DEM. This data is in ETRS89 (EPSG:4258), according to their site. Now, when I extract the elevation for a shore, I get 0 meters of ...
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1answer
296 views

Looking for topographic map of Bogota, Colombia, with elevation contour lines [closed]

I'm looking for a topographic map of Bogota, Colombia; specifically, we want to get the elevation contour lines, and export that layer to CAD. If anyone knows of any free places to find this data, we ...
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3answers
275 views

Will Topographic Position Index (Tpi) not work in scattered raster layers?

I have a non-continuous elevation raster layer and want to use tpi in the spatialEco package in R. The elevation raster is in EPSG:5677 and looks like this: I always get this (to me) rather cryptic ...
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1answer
238 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 ...
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1answer
260 views

In QGIS, my contour layer is always in meters despite settings, and DEM [closed]

I have a DEM file in Raster Layer that has elevations in meters, I have used the Raster Calculator to convert them to feet, and saved as a new DEM layer. The legend shows feet. When I run an ...
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1answer
978 views

How can I get the average elevation for an area in QGIS?

I have got .tif file for a country and a dbf file which divides the country area into 42 subunit. I want to get the average elevation data for each subunit in meters.
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2answers
527 views

Extracting peaks from DEM and creating 5 m elevation buffer around each peak in ArcGIS Desktop?

I have a DEM available and would like to identify all the peaks that are likely to be bare rock. I want to be able to isolate these areas and create a 5m elevation buffer around them to represent the ...
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2answers
182 views

Increasing Flood Plain

I am doing a project where we are attempting to determine how many more buildings would flood if the FEMA flood plain increased by 1',2' and 5'. I have the elev of the flood plain rasters from lidar ...
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98 views

Web page that dynamically draws contours at user specified elevation?

How might I setup a web page that will draw dynamically contours and/or hypsometric tints at a user specified starting elevation and/or interval? Example scenario: flood hazard modelling. The web ...
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1answer
236 views

GTOPO30 elevation value are wrong in QGIS

I downloaded GTOPO30 DEM archives from USGS(earthexplorer.usgs.gov/), and I just simply drag the file into QGIS, but somehow I find the elevation isn't the same with the actual scenery. I want to draw ...
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1answer
77 views

Volume estimation using multidate DEM

I have 10 multidate Cartosat-1 stereo pair derived raster DEMs of dates ranging over a decade over a river sand area. I want to derive volumes of sand deposited in that period within that area. Is it ...
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1answer
533 views

How to calculate difference in elevation between a POINT and the surrounding cardinal directions?

I have a POINT shapefile (Rain gauges) and a 100m DTM in the same coordinate system. Is there a method using QGis to calculate the difference in elevation between the elevation of each rain gauge ...
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1answer
155 views

GDALDEM hillshading running slow?

I have, for a while, been trying to make a terrain map using NASA's SRTM 3 dataset. I have a large (13 GB), geotiff projected to web mercator of all the elevation files provided. I have been able to ...
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2answers
711 views

Convert TIF to PNG without normalizing alpha

I'm trying to make some height maps with elevation data from https://earthexplorer.usgs.gov/. Since they give you assets in separate TIF tiles, I need to convert them to PNG and stitch them together ...
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1answer
133 views

Does gdal2tiles strip elevation data?

I have a GEOTiff file that has elevation data associated with it . It seems like the resulting png/jpg files I get after feeding it to gdal2tiles does not have elevation data. Same thing with the tms ...
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1answer
130 views

Automating calculation of cumulative elevation for multiple line segments (not the profile graph)

I'm using ArcGIS and am trying to figure out how to calculate the cumulative elevation gain (in feet or meters) for over 1,000 line segments representing separate, often unconnected trails. I have a ...
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1answer
28 views

ASCII Grid file doesnt have data matching NCOLS

I have an ASCII Grid file that states the following in its header: ncols 2205 nrows 653 . . . nodata_value -9999 But when going through the rows, the max number of cols is 12 and the number of rows ...
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1answer
180 views

DEM, points values and elevation to create a map of temeperature

I am using SAGA - Universal Kriging (Global) for this, but I am stucked. I have grid (.tif) for Serbia with elevation values, and .shp file with points that have mean yearly temperature. I want to ...
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0answers
98 views

AGOL “Elevation Layer (Hosted)” is not displaying outside of a narrow scale range

28/08/17 Edit: Solved. None of the errors or tools will specify this, but you need to manually generate pyramid layers on the input raster to have it display correctly as an elevation surface. ...
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1answer
217 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 ...
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1answer
641 views

Creating sloped lines from XYZ in QGIS

I have a dataset of lines with a start and end elevation value in the attribute table. I want to apply this value to the Z coordinate of the start/end vertex respectively to create a 3D line. The ...
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0answers
55 views

Buffer road line, taking into consideration elevation and upslope/downslope [closed]

I have a roads polyline layer. I have vector-based contour lines. I have converted those contours to a TIN, then created a raster based on that TIN. Now I have my roads and my elevation raster. Now I ...
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1answer
270 views

Merging raster elevation data

Using QGIS I have to merge 416 raster files with elevation data, at the beginning I´m using with only 4 of them to try out: When using "merge" (Raster > Miscellaneous) the result are a file with only ...
3
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1answer
177 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 ...
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1answer
251 views

Getting Hypsometric curve and Integral from elevation data in ENVI?

I am attempting to get the hypsometric curve (HC) and integral (HI) from some elevation data. The data I have is in ENVI format (ENVI ROIs and DEMs). Eventually, I would like to automate this, but for ...
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1answer
33 views

How to make new raster with higher values than the older one?

I'm working in ArcGIS and I have an elevation model of seaside. What I should do is to model an uplift of land, so make a new raster dataset in which will be higher values (for example to make a new ...
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1answer
43 views

Restrict geoprocessing from ArcGIS Server service

I have an Image Service up on our ArcGIS server. Its a DEM we are providing it to some of our partners. Works great and fast, but I want to turn off the ability to run tools from the service within ...
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1answer
248 views

Finding elevation of points using PyQGIS?

Which function and library do I use to find elevation of a set of points from shapefile in Python QGIS? I have point shapefile and DEM with me.
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1answer
670 views

Convert NGVD 1929 to NAVD 1988?

My root issue is that I have elevation values in NGVD 1929 that need to be related to a DEM which has elevation values in NAVD 1988. Is there a way that I can convert elevation from one data to ...
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1answer
231 views

TIN interpolation errors and weird lines [Qgis 2.18]

I want to create an elevation model in EPSG 4326 from 2 shapefiles [img0] : elevation lines [Altimetria linee Antrodoco] and elevation points [Altimetria punti Antrodoco], both obtained by the ...
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1answer
91 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 ...
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0answers
156 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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1answer
215 views

GRASS GIS: Interpolate DEM from irregularly spaced coastal survey data

I am attempting to interpolate the elevations of data sets of cross-shore survey transects. The data set size range from 50k to 300k points with ~100m between the transects and 1-5m between the points ...
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1answer
121 views

Convert elevation

I have a big trouble with a DTM. I have original DTM with SR WGS84/32633. Now I want merge at it a new DTM create from LiDAR data, but this (new DTM) have elevation that is 40/42 meters high that ...
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2answers
524 views

Get values of terrain elevation of roads in QGIS?

I have one DEM raster layer with elevation values and one vector layer of the roads; same size, extension and CRS. I want to do what this guy did here: http://youarealegend.blogspot.de/2012/07/...
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0answers
377 views

Reading SRTM30 Plus data with Python

From How to extract elevation from .HGT file? I know how to get the elevation from SRTM1 and SRTM3 files. But how to get elevation from SRTM30 Plus ftp://topex.ucsd.edu/pub/srtm30_plus/srtm30/data/ ? ...
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1answer
54 views

Handling an irregularly shaped elevation raster file

We are trying to process a set of elevation rasters of increasing resolution. We have a 30m resolution file that covers a large area, and a 5m resolution file that looks something like this image. ...
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1answer
102 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 ...
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2answers
675 views

GPS Elevation height

I want to calculate the height of an object based on nearest ground surface. I have GPS coordinates and GPS elevation(which I assume is ellipsoid height) as an input in WGS84 coordinate system. I read ...
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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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1answer
86 views

Conversion of elevation from Wusong Datum to Chinese 1985 National Datum to WGS84

I want to combine/compare raster data from a digital elevation model (EarthEnv-DEM90) with surface water level data from China. Unfortunately the water level data is given in a vertical Datum with ...
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1answer
881 views

Extracting values from raster to get elevation values in R?

I am trying to generate an isoscape using IsoriX in R. Here how my data looks: > head(dataC) siteID long lat animalID species tissue.value 1 A -5.88 53.82 CC1_33.2/1_15 ...
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0answers
61 views

Deriving Topographic Information from Geotagged Photos?

I wish to extract elevation data from geotagged photos? I have worked with DEM's and the open source CLI program: GMT for my graduate studies. I own a DJI Phantom 3 and used the trial version of ...
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1answer
355 views

Creating Buffer Polygon following Elevations using ArcGIS Desktop?

What I'm looking to do is put a 100 m buffer on a polygon, but rather than the buffer being at a fixed width "as the crow flies" I want it to follow the slopes of my Lidar DEM. I have ArcMap (with 3D ...
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0answers
234 views

Obtain elevation from a request lat,long with a map .tif

I am trying to get the elevation between two points in a route of Spain using APIs with HTTP request. I am using OpenStreetMap to get the routes, but I don't know how extract elevation with other tool....
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3answers
221 views

In DEM data there the elevation ranges from - 156 to 3877. What does this mean?

The elevation of that (project) particular landform cannot be negative (I think). Does this mean the DEM data is wrong?