Description of satellite information after the name
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The so-called "line 0" contains the name, dimensions, estimated standard
magnitude, and Radar Cross Section in the following format:
Columns
01-14 Name
17-20 Length, m (1)
22-25 Width, m (2)
27-30 Depth, m
31-35 Standard magnitude (at 1000 km range, and 50% illuminated) (3)
37-37 Standard magnitude source flag
39-42 Radar Cross Section value (4)
(1) If width and depth are zero, then the object is a sphere, and the
length is its diameter. Objects with unknown dimensions have been
assumed to be spherical, and a value of diameter has been
"guesstimated".
(2) If depth is zero, then the object is a cylinder, and width is its
diameter.
(3) The standard magnitude may be an estimate based on the mean cross-
sectional area derived from its dimensions, or it may be a mean
value derived from visual observations. The former are denoted by a
letter "d" in column 37; the latter by a "v". To estimate the
magnitude at other ranges and illuminations, use the following formula:
mag = stdmag - 15.75 + 2.5 * log10 (range * range / fracil)
where : stdmag = standard magnitude as defined above
range = distance from observer to satellite, km
fracil = fraction of satellite illuminated,
[ 0 <= fracil <= 1 ]
(4) The Radar Cross Section is a median value derived from the last several
years of values in the Satellite Situation Report. For classified objects
or newly-launched objects or objects without a value or with a clearly
erroneous value in the SSR, I have chosen a value. The units of the
RCS are square meters.
Ted Molczan, Sept. 23, 1996
Mike McCants, Jan. 9, 1999, June 7, 2004