the question asks you to make two line element it give you the given information and also everything is answered but the one thing i don't understand in here is how do the change the Epoch 29 sep 2010 18:00:00:00.000 to 10272.41666666. i need someone to explain this to me in detail.
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1$\begingroup$ have you done any checking of your own, on this site or elsewhere? Where, in your study, have you actually run into a problem? $\endgroup$– Erin AnneCommented Mar 31 at 9:56
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$\begingroup$ Welcome to Stak Exchange! There may be an answer to your question in the following. If you find it, you are welcome to post an answer to your own question. Convert TLE times (decimal days) to seconds after epoch and Time, UTC, Julian Date, TLE epoch - how are they related quantitatively? and How to obtain UTC of the epoch time in a satellite TLE (two line element)? $\endgroup$– uhohCommented Apr 1 at 2:22
1 Answer
The example you posted is erroneous. The format of the "Epoch Year & Julian Day Fraction" is yyddd.ffffffff
, where yy
is the last two digits of the year, ddd
is the day number of the year (sometimes called Julian day; do not confuse this with the concept of Julian dates), and .ffffffff
is the UTC time of day as a fractional number of days. So 10272.41666666 is not the correct representation of 2010 September 29 at 18:00:00 UTC. It instead corresponds to 2010 (10 means 2010) September 29 (September 29 is the 272nd day of the year in a non-leap year) at 10:00:00 UTC (0.4166666 = 5/12, or 10/24).