<DOC>
<DOCNO>
617
</DOCNO>
<TITLE>
determination of upper-atmosphere air density profile from satellite
observations .
</TITLE>
<AUTHOR>
groves, g.v.
</AUTHOR>
<BIBLIO>
proc. roy. soc. a. 252, 28-34, 1959 .
</BIBLIO>
<TEXT>
the theory previously developed for the changes in the perigee distance
and semi-major axis of a satellite orbit due to air drag is extended to
enable the air-density profile/i.e.its relative variation with height/to
 be derived from the motion of the orbit's perigee . the solution is
first obtained in terms of the change in perigee distance and then in
terms of the change in the radius of the earth at the sub-perigee point
 the scale height in the 180 and 220 km altitude regions .
</TEXT>
</DOC>
