Tagged Questions

The height of an object or point in relation to sea level or ground level.

learn more… | top users | synonyms

1
vote
0answers
61 views

Setting the correct zoom level from Sector bounds for flat map using WorldWind SDK

This is not coming out correct for me. Setting the zoom level based on some other code I got on here using the EarthFlat model, which does not set the correct zoom for the placemarks within a sector ...
1
vote
0answers
62 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 ...
0
votes
1answer
101 views

Z value (height,altitude) from 3D multipoint shapefile in QGIS

Is there a way to get Z value/height/altitude from 3D multipoint shapefile in QGIS? All I found is way through SpatiaLite or PostGIS as explained here: ...
0
votes
0answers
46 views

How to calculate raster distance with z value using ArcGIS for Desktop?

I'm trying to produce a raster distance map by using euclidean distance function having input feature as flight path (with altitude as Z value). However, my euclidean distance calculation did not ...
1
vote
1answer
211 views

How to calculate relative height of point on slope relative to nearest creek and ridge?

I'm attempting to calculate the relative height (values between 0 and 1 preferably) of waypoints on a slope along the path of least resistance. Ideally, points in creeks would have values of 0 and ...
1
vote
1answer
178 views

How can I add height data to a polyline in QGIS?

I want to place a polyline at the correct altitude in QGIS. Is that possible and how do I do this? What I have is a polyline (railroad) and I want to add information on the electrics above the ...
3
votes
1answer
75 views

How is elevation and altitude measured?

According to my watch that claims to measure altitude, as far as I can see it says that in Stockholm Sweden the altitude is 170 meters but can that be right? How exactly can we know that 0 altitude in ...
2
votes
0answers
118 views

Height of the geoid in ECEF coordinates

I know that the relationship of geoid height N and ellipsoid height h to orthometric height H is defined by H = h - N, but what if I have some position in Earth-Centered-Earth-Fixed (ECEF) ...
1
vote
0answers
401 views

Calculating Accurate % Grade from GPS Coordinates

I am trying to calculate % Grade from GPS points. I am using the basic equation of (Rise/Run)×100 The problem is I am getting spikes in my GPS data (example 1 meter rise for 3 meter run), I am ...
11
votes
1answer
425 views

Why does GPS altitude jump sometimes?

I am currently developing a little application in Android which uses GPS. When i click a button i start to record a "track". If i walk around i save my position every second into a file. This works ...
3
votes
1answer
684 views

How to get elevation with LibGeoTiff?

I'm trying to get an elevation profile from a geotif file ( downloaded from http://srtm.csi.cgiar.org/). I downloaded the libgeotiff library but i can's see any function that can return an elevation ...
6
votes
2answers
620 views

How to get latitude, longitude and altitude database from a GeoTIFF file?

I am developing an AR iOS application. When the iPhone gets the current location, it has to calculate locally the visible point. I want to read the tiff files in my application, and then get the ...
10
votes
2answers
349 views

What is my distance when viewing a scaled-topographic map?

A close friend from my company asked me a question about a topographic scaled map (1:25.000) that what was the altitude to a location in km (as you are viewing Earth from space) when he was viewing ...