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    Re: USNO Celnav data is back
    From: Paul Hirose
    Date: 2022 May 4, 16:52 -0700

    On 5/4/2022 7:00 AM, Dave Walden wrote:
    > For Assumed Position:    Latitude   N 39º 0.0',    Longitude   W 77º 0.0'
    > For 2022 May 4 at 2:44:00 UT
    
    All degree symbols in your post look like this: º, i.e., a tiny letter o
    with underscore. I do not see that on the web page, but when I copy and
    paste from the page to a document, the same thing happens. Some years
    ago I wrote about this phenomenon in some other context, but I can't
    remember the details.
    
    It's not clear to me why the application can't make life easy for the
    navigator by computing the expected topocentric angles. There could even
    be an input for height of eye. Instead, it takes the traditional
    approach where the navigator must correct the observed altitude to
    obtain the equivalent geocentric angle Hc.
    
    And I think it ought to compute Moon altitude for the appropriate limb,
    or just compute altitude of both limbs.
    
    The AM/PM UT1 input format is peculiar and annoying since the precise
    meaning of 12 AM is ambiguous. Is it 0000 or 2400? If you enter 00 hours
    the USNO application automatically changes to 12 AM. But that convention
    is not universal:
    
    
    https://www.whec.com/rochester-new-york-news/midnight-birth-leads-to-year-long-battle-over-birthdate/6452977/?cat=13421
    
    --
    Paul Hirose
    sofajpl.com
    

       
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