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Applet
Navigation
by
Lunar
Distance
Comparison
of
the
results
for
Lunar
Distance
1914
January:
| Jan 01, 12:00 UT |
Jan 06, 12:00 UT | Jan 20, 12:00 UT | |
| Almanac | 56° 59' 08'' |
111° 15' 53'' | 70° 57' 03'' |
| MICA | 56° 59' 19'' | 111° 16' 06'' | 70° 56' 55'' |
| Planets applet | 56° 59' 22'' | 111° 16' 04'' | 70° 56' 57'' |
The
MICA results (USNO
Multiyear
Interactive Computer Almanac) are computed from
the precise apparent geocentric latitudes and longitudes (True Equinox
and
Ecliptic of Date) using the formula:
The
error is <3'' for the Planets applet, <=13'' for the 1914 Almanac.
The
Planets applet is using the most important terms (J. Meeus:
Astronomical Alorithms) of the VSOP 87
theory
(error in latitude, longitude: Sun <1'', Moon: <10'', <4'').
Comparing
41
Lunar
Distances
the
mean difference between the "American Ephemeris
and Nautical Almanac for the Year 1911" and my Planets applet (using
∆T=ET-UT=0) is only 1.7''.
 |
The lunar
distance data window is available from the "Write/Draw" menu for the
Sun, and the bright planets. |
More features of the Planet Applet are described here
|
|
|
Lunar
distance (navigation) (Wikipedia) A Short Guide
to Celestial Navigation (PDF, Henning Umland) Angular Distances between two celestial objects and Lunar Calculation |
Updated:
2010,
Sep 15
©
2010 J. Giesen
