A
demonstration of the detection of an orbiting object via the drift-matching (DM) mode of
CCD operation.
The CCD
has been set such that its read direction and read rate exactly match the orbital
parameters of a
catalogued
object. In this example, the object is Satellite Number 14344 which is a piece of SL-8
debris with
a RCS
derived diameter of 12.5 cm. When crossing through the LMT FOV, the object was at an
altitude of
775 km
with an angular velocity of 0.5833 degrees/sec, a position angle of motion of 74 degrees
and a solar
phase
angle of 68 degrees. The CCD was oriented accordingly and then read at the corresponding
rate. The
object
signal photons were then able to accumulate on only several pixels rather than streak
through the FOV.
The
vertical streaks are background stars which are virtually stationary at this high read
rate and short effective
exposure
time of 0.585 seconds. Based upon the measured net flux above background (1900 ADU)
coupled with
the
assumption of a 0.1 albedo and a specular phase function, the object optical cross-section
(OCS) based diameter
is
approximately 5.12 cm. This white light image
was acquired with the LSP 2K CCD with 16x16 binning in order
to
accommodate the high angular rate and consequent short readout time.