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 -----------------------------------------------------------------------                          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.