NORAD Two-Line Element Set Format

NORAD Two-Line Element Set Format

As I mentioned in my previous publication, NORAD Two-Line Element Set Format is a standard operating procedure to transmit satellites orbital parameters.

For example:

123456789012345678901234567890123456789012345678901234567890123456789

NOAA 14

1 23455U 94089A   97320.90946019  .00000140  00000-0  10191-3 0  2621

2 23455  99.0090 272.6745 0008546 223.1686 136.8816 14.11711747148495

To facilitate the compression, I have added column number in the first row. As a result we can detect we have 69 characters.

Lines (0, 1 and 2) description:

– Line 0: satellite name

– Line 1 description:

 

Line 1

Columns Description Example
01 Row number 1
03-07 Satellite number 23455
08 Classification (U=Unclassified) U
09 None Â
10-11 International Designator (Last two digits of launch year) 94
12-14 International Designator (Launch number of the year) 089
15-17 International Designator (Piece of the launch) A00
18 None
19-20 Epoch Year (Last two digits of year) 97
21-32 Epoch (Day of the year and fractional portion of the day) 97320.90946019
34-43 First Time Derivative of the Mean Motion .00000140
45-52 Second Time Derivative of Mean Motion (decimal point assumed) 00000-0
53 None
54-61 BSTAR drag term (decimal point assumed) 10191-3
62 None
63 Ephemeris type 0
64 None
65-68 Element number 262
69 Checksum (Modulo 10)
(Letters, blanks, periods, plus signs = 0; minus signs = 1)
1

– Line 2 description:

Line 2

Columnas Description Example
01 Line Number of Element Data 2
03-07 Satellite Number 23455
08 None
09-16 Inclination [Degrees] 99.0090
17 None
18-25 Right Ascension of the Ascending Node [Degrees] 275.6745
26 None
27-33 Eccentricity (decimal point assumed) 0008546
34 None
35-42 Argument of Perigee [Degrees] 223.1686
43 None
44-51 Mean Anomaly [Degrees] 136.8816
52 None
53-63 Mean Motion [Revs per day] 14.11711747
64-68 Revolution number at epoch [Revs] 14849
69 Checksum 5