# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Location Center of Responses thus Far
From: Glendon
Date: 2001 Jul 23, 7:04 PM

```Its an optimisation problem isn't it?

Let x be the unknown location centre
Let D(i) be the great circle distance between the i th member and x
Then we want to choose x such as to:
minimise{sum of [ D(i); i=1-n]}

or, minimise{sumof[ square of D(i): i=1-n]}
subject to x lying between lat and lon of 0-360

hmmm, shipping or airline companies must have tackled this one??
Lee Martin
----- Original Message -----
From  "Dan Allen"
To:
Sent: Tuesday, July 24, 2001 7:23 AM
Subject: Location Center of Responses thus Far

> The following people have replied so far to my request for location:
>
> NAME             LAT     LON
> ================================
> Allen Dan        47.482  121.798
> Arrouye Yves     37.892  122.997
> Emerson Rick     40.245   75.252
> Gilbert Greg    -35.167 -138.75
> Hogan Dan        33.147  117.958
> Huxtable* George 51.6      1.28
> Murdoch* Bill    36.548   82.562
> Ouvry Philip     42.43    -3.15
> Sher* Russell   -33.933  -18.367
> Simmonds John   -37.353 -143.635
> Smith Peter      42.217   71.283
> Talge Gordon     34.052  117.253
> Taylor* Chuck    47.9    122.3
> Tripp Steven     37.5   -140
>
> * = Position approximated by looking up city in Encarta World Atlas
> (North and West are positive, South and East are negative)
>
> Using these 14 data points, the average latitude is 24.6 North,
> and the average longitude is 27.7 West, a spot 487 nautical miles
> north of Mindelo, Cape Verde islands in the central Atlantic ocean.
> This is quite a distance from the nearest restaurant.
>
> The nearest spot on a continent is Nouakchott, Mauritania, 761 nmi SE.
> It is 1177 nautical miles NE to Casablanca in Morocco.
>
> Hmmmm...
>
> Daniel K. Allen
> Measure | Analyze | Communicate
>
```
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