Parsing TLEs

This package contains functions to parse TLEs from strings and files.

Parsing TLEs from strings

The simplest way to parse one single TLE is using the macro @tle_str:

julia> tle = tle"""
           AMAZONIA 1
           1 47699U 21015A   23083.68657856 -.00000044  10000-8  43000-4 0  9990
           2 47699  98.4304 162.1097 0001247 136.2017 223.9283 14.40814394108652
           """TLE:
                      Name : AMAZONIA 1
          Satellite number : 47699
  International designator : 21015A
        Epoch (Year / Day) : 23 /  83.68657856 (2023-03-24T16:28:40.388)
        Element set number : 999
              Eccentricity :   0.00012470
               Inclination :  98.43040000 deg
                      RAAN : 162.10970000 deg
       Argument of perigee : 136.20170000 deg
              Mean anomaly : 223.92830000 deg
           Mean motion (n) :  14.40814394 revs / day
         Revolution number : 10865
                        B* :      4.3e-05 1 / er
                     ṅ / 2 :     -4.4e-07 rev / day²
                     n̈ / 6 :        1e-09 rev / day³

This macro considers only one TLE, leading to an error if the string contains additional information:

julia> tle = tle"""
           AMAZONIA 1
           1 47699U 21015A   23083.68657856 -.00000044  10000-8  43000-4 0  9990
           2 47699  98.4304 162.1097 0001247 136.2017 223.9283 14.40814394108652
           CBERS 4A
           1 44883U 19093E   23087.54098578  .00002943  00000+0  38100-3 0  9997
           2 44883  97.8669 167.4611 0001705  77.3129 282.8275 14.81612352176856
           """ERROR: LoadError: ArgumentError: The string `str` must contain only one TLE (2 or 3 lines).
in expression starting at REPL[1]:1

Multiple TLEs can be parsed using the macro @tles_str:

julia> tles = tles"""
           AMAZONIA 1
           1 47699U 21015A   23083.68657856 -.00000044  10000-8  43000-4 0  9990
           2 47699  98.4304 162.1097 0001247 136.2017 223.9283 14.40814394108652
           CBERS 4A
           1 44883U 19093E   23087.54098578  .00002943  00000+0  38100-3 0  9997
           2 44883  97.8669 167.4611 0001705  77.3129 282.8275 14.81612352176856
           """2-element Vector{TLE}:
 TLE: AMAZONIA 1 (Epoch = 2023-03-24T16:28:40.388)
 TLE: CBERS 4A (Epoch = 2023-03-28T12:59:01.171)

In this case, the result will always be a Vector{TLE}.

Note

We distinguished the parsing algorithm of one or multiple TLEs to avoid unnecessary allocations in the former.

@tle_str and @tles_str will always check the checksum of the two lines. If this verification is not desired, use the versions @tle_nc_str and @tles_nc_str.

If the TLE is programmatically added to a string, it can be parsed using the functions read_tle and read_tles for one or multiple TLEs, respectively.

julia> tle_str = """
           AMAZONIA 1
           1 47699U 21015A   23083.68657856 -.00000044  10000-8  43000-4 0  9990
           2 47699  98.4304 162.1097 0001247 136.2017 223.9283 14.40814394108652
           """"AMAZONIA 1\n1 47699U 21015A   23083.68657856 -.00000044  10000-8  43000-4 0  9990\n2 47699  98.4304 162.1097 0001247 136.2017 223.9283 14.40814394108652\n"
julia> read_tle(tle_str)TLE:
                      Name : AMAZONIA 1
          Satellite number : 47699
  International designator : 21015A
        Epoch (Year / Day) : 23 /  83.68657856 (2023-03-24T16:28:40.388)
        Element set number : 999
              Eccentricity :   0.00012470
               Inclination :  98.43040000 deg
                      RAAN : 162.10970000 deg
       Argument of perigee : 136.20170000 deg
              Mean anomaly : 223.92830000 deg
           Mean motion (n) :  14.40814394 revs / day
         Revolution number : 10865
                        B* :      4.3e-05 1 / er
                     ṅ / 2 :     -4.4e-07 rev / day²
                     n̈ / 6 :        1e-09 rev / day³
julia> tles_str = """
           AMAZONIA 1
           1 47699U 21015A   23083.68657856 -.00000044  10000-8  43000-4 0  9990
           2 47699  98.4304 162.1097 0001247 136.2017 223.9283 14.40814394108652
           CBERS 4A
           1 44883U 19093E   23087.54098578  .00002943  00000+0  38100-3 0  9997
           2 44883  97.8669 167.4611 0001705  77.3129 282.8275 14.81612352176856
           """"AMAZONIA 1\n1 47699U 21015A   23083.68657856 -.00000044  10000-8  43000-4 0  9990\n2 47699  98.4304 162.1097 0001247 136.2017 223.9283 14.40814394108652\nCBERS 4A\n1 44883U 19093E   23087.54098578  .00002943  00000+0  38100-3 0  9997\n2 44883  97.8669 167.4611 0001705  77.3129 282.8275 14.81612352176856\n"
julia> tles = read_tles(tles_str)2-element Vector{TLE}:
 TLE: AMAZONIA 1 (Epoch = 2023-03-24T16:28:40.388)
 TLE: CBERS 4A (Epoch = 2023-03-28T12:59:01.171)

If the user does not want checksum verification, pass the keyword verify_checksum = false.

Parsing TLEs from files

We can parse TLEs in files using the function read_tles_from_file:

julia> tles = read_tles_from_file("samples.tle")2-element Vector{TLE}:
 TLE: AMAZONIA 1 (Epoch = 2023-03-24T16:28:40.388)
 TLE: CBERS 4A (Epoch = 2023-03-28T12:59:01.171)

This function will always return a Vector{TLE}.