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Re: Moonrise-over-Connecticut
From: Paul Hirose
Date: 2021 Nov 7, 23:11 -0800

On 2021-11-07 21:00, I wrote:
> On 2021-11-05 14:30, Peter Blaskett wrote:
>>           Celestial Navigation Data for 2021 Nov  6 at 11 43 35 UT (GMT)
>>                                Delta T =  87.7 seconds
>>                   For Assumed Location:  Longitude       0 00.0
>>                                          Latitude        0 00.0
>
> At that time and place, with the ICE delta T, the Lunar 4.4 program gives:
>
> Moon geocentric apparent place
> 244°53.26' -21°54.44' equinox RA, dec
> 135°43.80' +58°35.81' geocentric az, el
>
> However, the correct delta T is 32.184 (a fixed value) + 37 (until the
> next leap second) - -0.107 (UT1-UTC from IERS Bulletin A). The sum is
> 69.29 s. With the correct delta T:
>
> 244°53.06' -21°54.39' equinox RA, dec
> 135°43.97' +58°35.99' geocentric az, el
>
> ICE altitude error is almost 0.2'.

Correction: 0.2' is the altitude error of my Lunar software if I force
it to use the ICE delta T, vs. its output with the actual delta T on
that date (second set of coordinates). I don't have ICE but would be
interested to hear what it says.

--
Paul Hirose
http://sofajpl.com/

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