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    Meaning of Tilde
    From: David C
    Date: 2016 Jun 20, 16:58 -0700

    I think that I know what (dec ~ lat) means but I am not completely sure. If I google ~ wikipedia gives dozens of meanings, none of which seem to match the navigation use. Navigation books usually give very wordy explanations if how to calculate it.

    My explanation is  (dec ~ lat) = mod(dec - lat)

    Example 1:   dec = N23°,  lat = S41°

         mod(dec - lat)     =   64°

    Example 2:       dec = S23°,  lat = S41°

       mod(dec - lat)     =   18°

    Example 3:   dec = S23°,  lat = N41°

         mod(dec - lat)     =   64°

    Am I correct?

    I have also seen the expression (dec +- lat)    (+- symbols stacked vertically). Is this an alternative  way of expressing the same idea?

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