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    Re: LAN curve parabola?
    From: David Fleming
    Date: 2019 Nov 22, 15:45 -0800

    Using a series of sights is attractive if you think of error reduction but in the practice of navigation is not lkely to result in an improvement justifying the work.

    Attached is a spreadsheet analysis of a long sequence of sights about MT that I carried out a while back.  It turns out that for latitude determination the clasic take a few sight at or about MT, graph them and eyeball the peak or tangency to a sloped line appropriate to the rate of change of dec for that day works better than any fancy math.

    I looked at rate analysis, plotting the rate of change of altitude over time, as a way of determining time of meridian transit and thereby longitude to a higher accuracy than graphing, to see if that is feasible.   But here least squared fitting did a better job than just a rate plot and not enough better to justify the work. 


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