Message-ID: <CANVKczOMqr6bu1vmL6YojdvYUTOSw0xrXJZT+x85MmGZXgizoA@mail.gmail.com>
Date: 2013-11-29T11:52:49Z
From: Barry Rowlingson
Subject: Taking elevation into account when calculating distance
In-Reply-To: <00a71e91955a45268ecbf4f2d88c0414@EX-0-HT0.lancs.local>
Ask Pythagoras?
On a small enough raster so that you can ignore the (nearly) spherical
earth its just sqrt(dx^2+dy^2+dz^2) where dz is the elevation
difference in the same units as x and y.
Sample the elevations from the raster using the functions in the
raster package. Job done?
Barry
On Fri, Nov 29, 2013 at 10:27 AM, John Tellat <john.tellat at gmail.com> wrote:
> Hi,
>
> I?m currently dealing with telemetry data combined with altitude
> measurements in a mountainous area with many valleys.
>
> I want to compute the straight distance between points but taking into
> account the elevation which is likely to extend the distance.
> Any idea on how to compute the "real distance" based on elevation raster
> data?
>
> Thanks!
>
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