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

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22 views

Extract value from Raster data by elevation

I have one raster data (AVHRR NDVI value) and one dtm data (elevation value). Is there anyway to know the NDVI value by 50m interval elevation? For example, I wanna know what is the NDVI value for ...
0
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0answers
35 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 ...
1
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0answers
28 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 ...
2
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2answers
32 views

find elevation for series of (lat,lon) combinations to make 3d model of earth with relief

I would like to say I am a complete novice to the world of GIS, so if I ask stupid questions or make strange assumptions, please point it out and I will try to clarify myself. I would like to make a ...
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1answer
27 views

How do I take a contour .shp file and create a separate layer for each elevation?

The end result is to have a .dxf file in which each different elevation resides in a different layer. If at all possible I would like to be able to do the organizing in tile mill, or through some ...
1
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0answers
17 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 ...
1
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2answers
55 views

Where do I get Elevation Data for Scotland?

So I am new here and I arrived here because I have been searching for quality elevation data for the entire Scotland but I have not succeeded yet. Kindly help if you know where to get the data Raster ...
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0answers
27 views

How to get elevation of a coordinate given a dtm file out of a PostGIS?

What would be the best way to get elevation of a coordinate out of a PostGIS database (SQL/plpgsql) given a GeoTIFF dtm file? Importing as PostGIS Raster (which seems more costly) and calling ...
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0answers
38 views

Converting from WGS84 Ellipsoidal Height to NAVD88 Orthometric Height

Is anyone aware of a way to batch convert or project elevation z-values from a point from WGS Height Above Ellipsoid (standard GPS height) to ortometric NAVD height using the GEOID03 model in ...
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0answers
50 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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0answers
15 views

What is the best option for web elevation profile using in-house DEM?

ArcGIS Server requires the advanced license for the 3D analysts extension. Are there any open source options? Thanks
2
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3answers
92 views

How to update the Z value using an UpdateCursor?

I have created the following script to mimic the ArcGIS 3D Analyst tool, FeatureTo3DByAttribute, which creates a 3D copy of a 2D feature class and sets the Z to a specified attribute. import arcpy, ...
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0answers
37 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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0answers
26 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 ...
2
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0answers
38 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 ...
1
vote
1answer
59 views

Displaying DEM with real elevation values in ArcGIS Desktop?

I am trying to create a DEM with hillshading map in ArcGIS Desktop 10, but I'm getting the result with scale values between 0 and 254. How can I display the scale with the real elevation values? ...
1
vote
1answer
43 views

Changing the Axis on a Profile Graph

I'm working on a map with forest trails and I want to get an elevation profile of them all individually. I have gone through and interpolated the trail layer with a DEM so that I can use the 3D ...
0
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2answers
53 views

Calculate mean elevation over a region

For the purposes of spatial interpolation, I have created a grid using "Create Fishnet" in ArcMap10.2 (I use the "label points", which have a spacing of 0,00833333 degrees). For every point (label ...
0
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1answer
58 views

How to obtain elevation value from given SRTM data on mouse click in web browser?

I need JavaScript code for obtaining elevation data from SRTM tiff image. I have used Google APIs, but I need for downloaded SRTM tiff image. (SRTM file is being loaded on a base layer, and both ...
-1
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1answer
33 views

How to decrease elevation values of DEM using open source GIS sotware? [closed]

I am newbie in QGIS, but I was wondering how to decrease elevation dem DEM using QGIS? Can QGIS do that? Or anyone of you can tell me any open source GIS software to perform that?
0
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0answers
22 views

Where can I download 1/9 arc-second elevation data for the Hawaiian islands?

In same spirit as this question, I'd like to know where I can find 1/9 arc-second elevation data for the Hawaiian islands. The USGS national viewer provides 1/9 arc-second data for certain places, ...
4
votes
1answer
118 views

Identifying south facing mountain land, above an elevation, within a slope range, less than fixed distance from major roadways

This odd question comes from believing that such an analysis is plausible in a GIS system. Only, I don't how to accomplish the various discrete steps implied from the Title, nor where to get a topo ...
3
votes
1answer
137 views

How to subtract out the slope (in general) of a DEM?

I'm searching for a solution process to subtract out the slope of a DEM like this: I have a high resolution DEM and want to reconstruct historical/old/not active parts of a river. The problem is ...
0
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1answer
39 views

Want to intersect a polygon of a certain elevation with a tin surface

so I want to generate a flood plain for a river in ArcMap. Basically this means that I want to create polygons with certain elevations above the drainage point elevation (870 m). For instance I would ...
0
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1answer
37 views

Web site to show GPX with elevation?

I notice that a GPX file contains not only lat + lon but also elevations: <trk> <name>Some route</name> <trkseg> <trkpt lat="50.64536" lon="3.05657"> ...
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1answer
65 views

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

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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1answer
92 views

Learning about bathymetry?

Besides reading about bathymetry, I would like to work on some hands-on training that I can learn about bathymetry. Is there any good bathymetry out there that I can get some training with the ...
1
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0answers
17 views

QGIS Extract elevation data only for one country [duplicate]

Hye, Here a map built with (1) a shape file for country contour, and (2) raster from .hgt files with altitudinal representation. How can I only select the area corresponding to the country ? I found ...
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0answers
38 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 ...
6
votes
1answer
128 views

What resampling technique should be used to reproject an altitude raster?

Does anyone know whether I should choose: nearest, bilinear, cubic or majority when projecting the WorldClim altitude raster layer?
2
votes
2answers
73 views

Check if a polygon is at one elevation

I have a polygon (pond) and I need to ensure it is at one elevation. I have converted all vertices of the polygon to points, used summary statistics to determine the range in elevations and if the ...
1
vote
1answer
67 views

Select points with lowest elevations and same x,y coordinates

The problem is as following, I have a point layer with x,y,z coordinates. Some of the points have same x,y but different z. I need to separate points without duplicates (x,y) and in case there are ...
3
votes
2answers
82 views

How do I get rid of this thin band between raster layers created from TNM?

After hitting my head against the table for many days, I'm humbly presenting myself to the QGIS community. I downloaded 4 IMG files (1/3 arc second, elevation data) from The National Map on the USGS ...
1
vote
2answers
76 views

Interpolate dxf polyline vertex elevation from DTM?

I am working on several autocad polylines (with several vertices...) that have the exact N,E coords but now I would like to add the elevation data for every polyline's vertices from a dtm. I thought ...
2
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0answers
30 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 ...
2
votes
1answer
28 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
votes
0answers
115 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
votes
0answers
26 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 ...
4
votes
1answer
184 views

Creating a point corresponding to the maximum elevation of a DEM [duplicate]

I am wondering how can I create a point corresponding to the maximum elevation value of a DEM. I mean, from the DEM I can easily get the maximum elevation. For the sake of a viewshed analysis, I would ...
2
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0answers
113 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 ...
2
votes
0answers
37 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
votes
1answer
25 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 ...
3
votes
0answers
66 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 ...
1
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0answers
53 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 ...
2
votes
1answer
118 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 ...
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0answers
20 views

How to merge elevation from a raster image onto a shape road network with QGIS? [duplicate]

I have a shape file with Stockholms road network and a raster image with elevation data from the same area. Is there any way to merge the two somehow, either by adding the slope direction as ...
0
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0answers
60 views

How to calculate fastest bicycle routes in Stockholm with QGIS?

Hello StackExchangers, I would really appreciate if expert users could point out a few directions for me, this is what I wanna do: Access an online map from my iPhone that gives me the possibility ...
3
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0answers
446 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.
6
votes
2answers
139 views

Reducing elevation from DEM using ArcGIS for Desktop?

I am so curious how would I strip off elevation from the DEM. I don't know how I would explain it further but I have attached an image to clarify this. I wanted to eliminate the area shaded with ...
2
votes
1answer
156 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? ...