Ethnocentric USian that I am, I've assumed that we and the
xUSSR were the only countries with significant capabilities to track
non-cooperative objects in low Earth orbit. Grazing in a couple of 
databases recently,  I found that Japan has some optical capabilities
along this line, and also uses a radar designed for other purposes
for orbital debris surveys (it isn't clear whether the radar can 
determine orbital elements for the objects it detects). Abstracts of 
the articles are appended. 


    This leads to the more general question: do yet other people than 
the US, Russia, and Japan do space surveillance, and if so, how and 
why? 

Allen Thomson              SAIC                        McLean, VA, USA
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                         ABSTRACTS

Optical tracking of the experimental geodetic satellite (EGS)
TAKABE, MASAO; ITABE, TOSHIKAZU; ARUGA, TADASHI
Radio Research Laboratory, Review (ISSN 0033-801X), vol. 34,
March 1988, p. 23-34. In Japanese, with abstract in English.
     This paper reports the optical tracking results of EGS
(experimental geodetic satellite) which was launched on August 13,
1986, by NASDA. The EGS optical tracking experiment process and an
outline of the Radio Research Laboratory (RRL) optical ground       <----
station are discussed. A star tracking technique for optical
equipment calibration and satellite tracking technique for orbit
prediction improvement are also described. The accuracy of EGS
tracking data obtained by RRL at the request of NASDA is also
discussed. In addition, it is briefly demonstrated that the
position of the Japanese amateur satellite (JAS-1) which was
launched with the EGS, was accurately determined by means of a      <----
satellite tracking video. It is clear from this experiment that     <----
optical observation data (i.e., satellite direction data) are very  <----
useful for satellite orbit determination during initial launch      <----
stages. Furthermore, the results confirm the effectivenes of these  <----
two satellite optical tracking techniques.                          <----


MU radar measurements of orbital debris
SATO, TORU; KAYAMA, HIDETOSHI; FURUSAWA, AKIRA; KIMURA, IWANE
(Kyoto University, Japan)
AIAA, NASA, and DOD, Orbital Debris Conference: Technical Issues and 
Future Directions, Baltimore, MD, Apr. 16-19, 1990. 10 p. 
RPN: AIAA PAPER 90-1343
     Distributions of orbital debris versus height and scattering cross 
section are determined from a series of observations made with a high-
power VHF Doppler radar (MU radar) of Japan. An automated data 
processing algorithm has been developed to discriminate echoes of 
orbiting objects from those of undesired signals such as meteor trail 
echoes or lightning atmospherics. Although the results are preliminary, 
they showed good agreement with those from NORAD tracking radar      <----
observations using a much higher frequency. It is found that the     <----
collision frequency of a Space Station of 1 km x 1 km size at an 
altitude of 500 km with orbiting debris is expected to be as high as 
once per two years. 


Monitoring of the MU radar antenna pattern by Satellite Ohzora (EXOS-C)
SATO, T.; INOOKA, Y.; FUKAO, S. (Kyoto Univ., Japan); KATO, S.
Kyoto Univ., Uji (Japan). Radio Atmospheric Science Center.
In International Council of Scientific Unions, Middle Atmosphere Program.
Handbook for MAP, Vol. 20 5 p
Publication Date: Jun. 1986
      As the first attempt among MST (mesosphere stratosphere 
troposphere) type radars, the MU (middle and upper atmosphere) radar 
features an active phased array system. Unlike the conventional large 
VHF radars, in which output power of a large vacuum tube is distributed 
to individual antenna elements, each of 475 solid state power amplifier 
feeds each antenna element. This system configuration enables very fast 
beam steering as well as various flexible operations by dividing the 
antenna into independent subarrays, because phase shift and signal 
division/combination are performed at a low signal level using 
electronic devices under control of a computer network. The antenna 
beam can be switched within 10 microsec to any direction within the 
zenith angle of 30 deg. Since a precise phase alignment of each element 
is crucial to realize the excellent performance of this system, careful 
calibration of the output phase of each power amplifier and antenna 
element was carried out. Among various aircraft which may be used for 
this purpose artificial satellites have an advantage of being able to 
make a long term monitoring with the same system. An antenna pattern 
monitoring system for the MU radar was developed using the scientific 
satellite OHZORA (EXOS-C). A receiver named MUM (MU radar antenna 
Monitor) on board the satellite measures a CW signal of 100 to 400 
watts transmitted from the MU radar. The principle of the measurement 
and results are discussed.
