|
|
Subject: occultations of jupiter's satellites
From: Federico Rossi (fedeastro.rossi@XXX.XXX)
Date: Sun Apr 06 2003 - 13:01:24 EDT
I've read Arthur Pearson's contribution about Lunar distances and found it very interesting.
As far as getting accurate time at sea is concerned, I think another method is worth noting.
My father was an Italian merchant marine officer during the '60: an older officer once told him he had still used a method based on timing the occultations of Jupiter's Galilean satellites to get the K of chronometers, probably before WWII when accurate radio timing signals were not always available. A long focus telescope was installed on the bridge and, comparing the timing of the occultation given by the nautical almanac and the time given by the chronometer, one could obtain the correction later used to reduce star sights. This method doesn't even need to take sights with sextant and, in periods of good Jupiter visibility, several occultations occurs every day.
Have you ever heard about this technique?
Federico Rossi
|