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    Re: Symmedian talk
    From: Bill Lionheart
    Date: 2017 Feb 25, 20:11 +0000

    Yes the Wikipedia animation was a compromise but the audience got the
    idea.  I wish I was good at making diagrams (and animations) myself. I
    would love a better one to illustrate a circle of position around the
    GP for example. Any suggestions of diagrams (that are free to use)
    gladly received. As you correctly understood this audience has
    probably never thought about celestial navigation before.
    Github is a bit daunting - but everything is there somewhere. Each
    time I give the talk I update to slides and make a "release" (just
    like it was any other software).
    The link to the version of slides for this talk is on this link
    and the slightly updated one with improveents here
    [The watch  is my old Suunto Vector -1 sec per 4.3 days but at least
    it is consistent when strapped to my wrist. Great alto/baro but
    rubbish fluxgate compass - and no it has no freeze-time facility! Big
    enough to read without glasses, waterproof enough for sailing but not
    So of course it is easy to (algebraically)  handle different variances
    in the Gaussian distribution of errors, or even a known covariance
    matrix if the errors are correlated. You gust change coordinates then
    do the standard least squares problem and change back when you have
    finished. Technically this is a change of Euclidean metric, but it is
    still a flat metric, so you can still use Euclidean Geometry.  I can
    see I am going to have to give a special NavList edition of the talk
    at some point!
    On 25 February 2017 at 19:08, Greg Rudzinski  wrote:
    > Thanks Bill ,
    > I really enjoyed your lecture :)) Now please tell us what kind of very large
    > watch is on your left wrist.
    > To further complicate the triangle center- what happens to the triangle
    > center when we attach a confidence value to each individual LOP ? I call
    > this a "calling the shot percentage".
    > Greg Rudzinski
    > From: Bill Lionheart
    > Date: 2017 Feb 25, 10:12 -0800
    > We videoed my talk to school students on the symmedian point and navigation.
    > https://youtu.be/pzDyi7ANoVA. OK so the video is not so good as the
    > projector saturates the camera - slides are added in the corner. So by now
    > NavListers all know about the symmedian point!
    > I am just sharing this and all the source materials for the slides including
    > both Euklides and Geogebra code for drawing symmedian points here on Github
    > https://github.com/billlion/symmedian-talk, just in case any members want to
    > make a similar (better I hope) talk on geometry and navigation!
    > I have given the talk a few times since and got a bit better. I pass around
    > Colin Steele's old sextant (which I shared earlier) and they seemed to like
    > that.
    > View and reply to this message
    Professor of Applied Mathematics

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