1

I was wondering where I could find the TLE of a satellite ( I am looking for CASSIOPE). I went into this link - https://www.n2yo.com/satellite/?s=39265 but it has only got the most recent updated TLE. I would like to have the TLE of the past few days of December and searched a lot for the same but in vain. Don't they store the TLE history just like IERS stores the earth orientation parameters along with other quantities on their website?

budding physicist
  • 51
  • 4

1 Answers1

2

For the latest TLES you can use Celestrak; 1, 2, 3 and there are some collections of some historical (but not recent) TLEs as well.

You can access a huge collection of historical TLEs in Space-Track after you register and read the rules. See this answer for more on that. When I first started I also though I'd have to scrape them from websites!

See also Why Celestrak has Archived TLEs for most space stations from Russia and the US, but not Tiangong-1, Tiangong-2 or Skylab?

update: For CASSIOPE (39265, 2013-055A) (CAScade, Smallsat and IOnospheric Polar Explorer, see pdf linked there for more) the Canadian Space Agency's (CSA) multi-mission satellite operated by MacDonald, Dettwiler and Associates (MDA):

Community
  • 1
uhoh
  • 148,791
  • 53
  • 476
  • 1,473
  • 1
    Thank you so much for the links. I was just wondering what the latitude and longitude values in the link - https://epop.phys.ucalgary.ca/where-is-cassiope/ actually mean? Are they the geocentric latitude and longitude values of the satellite at that particular time? – budding physicist Dec 08 '19 at 20:34
  • 1
    @MahithM I think that's an excellent guess considering that there's an altitude there as well. In order to generate the image of the map with a satellite on it that's on that page (or on any page at n2yo where you stated your question) you need a lat/lon pair to place the picture of the satellite. – uhoh Dec 08 '19 at 23:56
  • 1
    @MahithM The exact definition they use to calculate the sub-satellite point is uncertain since there are three different definitions of "up" from a given point on the Earth (1, 2), but it's probably the lat/lon of the sub-satellite point on the WGS84 reference sphere. If you use Python then Skyfield works nicely to process TLEs and it also has a .subpoint() method. – uhoh Dec 08 '19 at 23:59