

WORK IN PROGRESS  TESTING
The purpose of this page is to help you convert NORAD 2 line elements to Charlie elements. Get hold of your original data as a text file. Try opening an example text listing of Cubesat 2 line elements. Use Microsoft Notepad or similar simple text reader.
From your text file, highlight and copy and paste your selected three lines of text data into the text input box below. Hint: Copy is Control C. Paste is Control V. Then click the button below to make the conversion and generate the output text line.
One line Charlie element.
Analysis and processed output from line 1.
Analysis and processed output from line 2.
Unused miscellaneous data.
25th Sept 2016: This calculator is new and not fully tested. Use for the moment is for testing and verification purposes only.
The result for drag is dubious. If the input is " 100003" as per the default above the Charlie output should be 6 digits. I don't know how to convert this variable. At present it converts as 000100
The other results may be in error and should not be used for for anything important or orbital manoeuvres or the navigation of real spacecraft. You have been warned ! If anyone uses this page and is able to do the calculations independently themselves or with other software please tell me eric@satsig.net where I am right and where I am wrong.
TTTTTTTTTTTTTTTTTTTTTTTT O3B FM4 1 NNNNNT NNNNNTTT NNNNN.NNNNNNNN +.NNNNNNNN +NNNNNN +NNNNNN N NNNNN 1 39189U 13031B 13322.55940486 .00000028 000000 100003 0 390 2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN 2 39189 0.0361 358.2964 0001026 0.7257 0.9823 5.00115079 7309 123456789012345678901234567890123456789012345678901234567890123456789 1 2 3 4 5 6
First text line: Up to 24 text characters. Text name as used in common public documents and adverts. It may vary with time due to change of owner/lessee and marketing ideas. Names may be changed as a result of change in the orbit position of geostationary satellites.
Line 1 explanation: Column number meanings
1 If set to 1, indicates line 1 of two element data set
37 Satellite number
8 Classification: U=unclassified
1011 International Designator (Last two digits of launch year 19571999, 20002056)
1214 International Designator (Launch number of the year)
1517 International Designator (Part off the launcher, letters A, B, C ... AA, AB, etc)
1920 Epoch Year (Last two digits of year 5799, 0056)
2132 Epoch Day of the year with leading zeros and fractional portion of the day.
3443 First Time Derivative of the Mean Motion
4552 Second Time Derivative of Mean Motion (decimal point assumed)
5461 BSTAR drag term " NNNNNN" assumed to mean 0.NNNNN, then apply N as power of 10
54: First character may be + or blank.
I am uncertain how this BSTAR drag term converts to 6 digits in Charlie one line elements.
I have assumed that +123453 converts to 000123, units of revs/day^2. This may be all wrong. The term may alternatively be a drag coefficient.
63 Ephemeris type
6568 Element number
69 Checksum
Line 2 explanation: Column number meanings
1 If set to 2, indicates line 2 of two elements data set
37 Satellite number
916 Inclination NNN.NNNN deg. Leading zeros may be absent. Converts to NNNNNN which means NNN.NNN
1825 Right Ascension of the Ascending Node NNN.NNNN deg. Leading zeros may be absent.
2733 Eccentricity NNNNNNN means .NNNNNNN
3542 Argument of Perigee deg NNN.NNNN converts to NNNNNN which means NNN.NNN
4451 Mean Anomaly deg NNN.NNNN converts to NNNNNN which means NNN.NNN
5363 Mean Motion revs per day NN.NNNNNNNN converts to NNNNNNNN which means NN.NNNNNN
6468 Revolution number at epoch revs
69 Checksum
The oneline Charlie element format is still used as an input format for some older satellite dish pointing software and for some military applications. It comprises a single line of 60 decimal digits. The meaning of column numbers is as follows:
130311332255940400010000003635829600010200072500098205001150 123456789012345678901234567890123456789012345678901234567890 1 2 3 4 5 6
15 NORAD Catalogue Number.
67 Epoch year (Last two digits of launch year 19571999, 20002056).
810 Epoch Day of year with leading zeros NNN
1116 Fraction of a day of epoch NNNNNN means .NNNNNN
1722 Drag. NNNNNN Uncertain could be revs/day^2 or a drag coefficient
2328 Inclination NNNNNN means NN.NNN deg
2934 Right Ascension of Ascending Node (deg) NNNNNN means NNN.NNN
3540 Eccentricity NNNNNN means NNNNNN
4146 Argument of Perigee (deg) NNNNNN means NNN.NNN
4752 Mean Anomaly, (deg) NNN.NNNN convetts to NNNNNN means NNN.NNN
5360 Mean Motion, (rev/day) NNNNNNNN means NN.NNNNN
Known possible software problem (not resolved)
The web page program needs to identify the start of each data line. It looks for matching sequences of "1 NNNNNT" or "2 NNNNN ", where N is a digit and T is text character, and space is a space character. This will not work properly if there is false match due to unusual satellite text name of the data input is not as I have assumed. Please tell me if you ever see this.
Any problems, suggestions for improvements or comments, please email me
Eric Johnston Page started 22 Sept 2016, amended 14 Dec 2023. 