Having a TLE data, how do I update it with -let's say- today's date ?
I have the TLE of the ISS, I concluded that in order to have the location of the satellite at the moment, columns 21 to 32 should be altered with the date at the moment.
I have no problem with columns 21,22,23, but the rest are the problem (up to 32). I tried to convert to epoch time, but it's not giving me "8 slots"; rather 10. I couldn't understand what is meant by " Epoch (day of the year and fractional portion of the day". I tried to convert the time to many forms, but it either yields "6 slots" or "10 slots".