This experiment was designed to determine nonsystematic changes of upper
atmospheric density by conducting studies of the drag on a 3.6-m diameter,
low-density sphere caused by short-term variations in solar activity. Density
values near perigee were deduced from sequential observations of the spacecraft
position using optical (Baker-Nunn camera network) and radio/radar tracking
techniques. The ... general techniques used to deduce density values from satellite
drag data can be found in L. G. Jacchia and J. Slowey, 'Accurate drag
determination for eight artificial satellites of atmospheric densities and
temperatures,' Smithsonian Astrophysical Observatory special report no. 100,
Cambridge, Mass., July 1962.
Predicted world maps and atmosphere drag density tables on microfiche are
archived at NSSDC.