TLE dates are not Julian Day numbers (sequential), but of the form YYDDD.dddddddd In a spreadsheet, put the tle day number in column A, and the following formula (Excel 2002 format, counting dates as no. of days since 1899-12-31) in column B: =A1-INT(A1/1000)*1000+INT(365.25*INT(A1/1000-1))+IF(A1>57000;366;36891) Set the format of column B to date+time (in Excel YYYY-MM-DD hh:mm:ss.ss) (Column A could be 00000.00000000) The first term gives correct dates for 2000-01-01 to 2000-02-28. The second term corrects the date - but not the year - of all non-leap years 2000-2099 The third term corrects all years 2000-2099, if the fourth term is a hardcoded 36891 The fourth term corrects years 1957-1999. ----- Original Message ----- From: "Thomas Fly" <thomasfly@charter.net> To: <SeeSat-L@satobs.org> Sent: Thursday, February 27, 2003 2:16 AM Subject: Re: day/month/year/UTC > From: "Tom Wagner" <sciteach@mchsi.com> > > > I'm looking at some archived 2-line TLEs and I need to know how to convert > > the seconds past whatever year it is is to day/month/year/UTC. Do I need > to > > find an online conversion or what? > > Two-line element format: > http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSS OP/ > SSOP_Help/tle_def.html > > http://aa.usno.navy.mil/data/docs/JulianDate.html can convert a calendar > date to Julian date, and vice-versa. > > ----------------------------------------------------------------- > To unsubscribe from SeeSat-L, send a message with 'unsubscribe' > in the SUBJECT to SeeSat-L-request@satobs.org > List archived at http://www.satobs.org/seesat/seesatindex.html > > ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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