NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Frank's Lunar calculator
From: Alexandre Eremenko
Date: 2006 May 7, 00:03 -0500
Frank,
It seems to me that your Lunar calculator
contains a little bug.
Its output is two numbers:
the error in the Lunar distance and
the error in longitude.
Both numbers have signs, plus or minus.
The bug is that the sign of both numbers
is always the same:-)
In reality, the sign of the error in longitude
is sometimes the same as the sign of the error in distance,
sometimes the opposite, depending on the limb used.
If the Moon moves towards a star overshot in the distance
means underestimate of the time, and vice versa.
(You wrote once that your error in longitude is simply obtained
by multiplication of the error in distance by 30.
But one has to take the sign into account, the sign nedends
on the limb used).
Alex
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From: Alexandre Eremenko
Date: 2006 May 7, 00:03 -0500
Frank,
It seems to me that your Lunar calculator
contains a little bug.
Its output is two numbers:
the error in the Lunar distance and
the error in longitude.
Both numbers have signs, plus or minus.
The bug is that the sign of both numbers
is always the same:-)
In reality, the sign of the error in longitude
is sometimes the same as the sign of the error in distance,
sometimes the opposite, depending on the limb used.
If the Moon moves towards a star overshot in the distance
means underestimate of the time, and vice versa.
(You wrote once that your error in longitude is simply obtained
by multiplication of the error in distance by 30.
But one has to take the sign into account, the sign nedends
on the limb used).
Alex
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---