<DOC>
<DOCNO>
614
</DOCNO>
<TITLE>
the contraction of satellite orbits under the influence of air drag .
</TITLE>
<AUTHOR>
part ii . with oblate atmosphere .
</AUTHOR>
<BIBLIO>
king-hele, d.g., cook, g.e. and walker, d.m.c.
r.a.e. tn. gw. 565. 1960 .
</BIBLIO>
<TEXT>
part ii . with oblate atmosphere .
the effect of air drag on satellite orbits of small eccentricity e/0.2/
was studied in part i/technical note no.g.w.533/on the assumption that
the atmosphere was spherically symmetrical . here the theory is extended
 to an atmosphere in which the surfaces of constant density are
spheroids of arbitrary small ellipticity . equations are derived which
show how perigee distance and orbital period vary with eccentricity, and
 how eccentricity is related to time . expressions are also obtained
which give lifetime and air density at perigee in terms of the rate of
change of period . in most of the equations, terms of order e and higher
 are neglected . the results take different forms according as the
eccentricity is greater or less than about 0.025, while circular orbits
are dealt with in a separate section . the results are also presented
graphically in a manner designed for practical application, and examples
 of the theory in use are given .
the influence of atmospheric oblateness is difficult to summarize fairly
simultaneously assume their'worst'values, some of the sphericalatmosphere
results can be altered by up to 30( as a result of oblateness
and 5-10( would be a more representative figure .
</TEXT>
</DOC>
