m.e.ash   may 1974   subroutine norad
read norad 2 card mean elements and convert to osculating
cartesian coordinates by applying kozai corrections
norad = north american air defense, satellite part of which is now
called the space defense center (sdc)

format of space defense center 2 card classical mean elements
card 1
col   name  description                            units  field format
1     linno line number (always 1 for card 1)      none              x
2     blank
3-7   satno satellite number                       none          xxxxx
8     clasi element classification(u=unclassified, none              x
c=confidential, s=secret)
9     blank
10-11 idyr  international designator (last two     launch           xx
digits of launch year)                 yr
12-14 idln0 international designator (launch       none            xxx
number of the year
15-17 idpn0 international designator (piece of     none            xxx
launch)
18    blank
19-20 epyr  epoch year (last two digits of year)   epoch yr         xx

21-32 epoch epoch (day and fractional days of the  utc    xxx.xxxxxxxx
year (jan 1 is day 1)                  days
33    blank
34-43 ndot2 first time derivative of the mean motion
34-43 ndot2 first time derivative of the mean      revolu- +-.xxxxxxxx
or   motion or ballistic coefficient        tions   (if ndot2
bterm (depending on ephemeris type)          /day**2 .gt.1, +
or m**2 w/o sign)
/kg
44    blank
45-52 ndot6 second time derivative of mean motion  revolu-   +-xxxxx-x
(field blank if ndot6 not applicable)  tions    (decimal
/day**3  pt assumed
between
cols 45&46
53    blank
54-61 bstar bstar drag term if gp4 general pertur-           +-xxxxx-x
or   bations theory was used. otherwise will
agom  be the radiation pressure coefficient.
62    blank
63    ephtyp ephemeris type (specifies ephemeris   none              x
theory used to produce elements)
64    blank
65-68 elno  element number                         number         xxxx
69    cksum check sum (modulo 10)                  none              x
card 2
col   name  description                            units  field format
1     linno line number (always 2 for card 2)      none              x
2     blank
3-7   satno satellite number                       none          xxxxx
8     blank
9-16  ii    inclination                            degrees    xxx.xxxx
17    blank
18-25 node  right ascension of ascending node      degrees    xxx.xxxx
26    blank
27-33 ee    eccentricity (decimal pt assumed)      none       .xxxxxxx
34    blank
35-42 omega argument of perigee                    degrees    xxx.xxxx
43    blank
44-51 mm    mean anomaly                           degrees    xxx.xxxx
52    blank
53-63 nn    mean motion                            revolu- xx.xxxxxxxx
tions
/day
64-68 revno revolution number at epoch             revolutions   xxxxx
69    cksum check sum (modulo 10)                  none              x