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    Re: Anti-spoof testing my sextant
    From: Frank Reed
    Date: 2020 Jan 30, 18:07 -0800

    I wrote:
    "What you should look at it is the average and standard deviation of your nineteen cells H6 through H24, which show the difference between the app-predicted altitude and your observed altitude."

    I intended to mention that these differences are identical to "intercept" values. In traditional celestial navigation, we observe Hs and apply various corrections to get Ho. Then we look up in tables or do some math to get Hc. And the intercept Ho-Hc is telling us how far our line of position is from our initial (AP) position. But from a modern perspective, we can get the machine to directly calculate what our Hs ought to be from our known exact position (equivalent to an AP from the point of view of the computation). Any error in observation tells us how far our LOP from that sight would be from our true position.

    Frank Reed

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