A.G.Kirichenko, L.M.Kizyun,V.U.Klimik,K.A.Kudak, G.M.Matso, M.I.Demchyk. CATALOGUE GOCKU99 OF POSITIONS AND ORBITAL ELEMENTS OF GEOSYNCHRONOUS SPACE OBJECTS OBSERVED IN 1999. PECULIARITIES OF CONTROLLED GEOSYNCHRONOUS SATELLITES IDENTIFICATION

   Abstract. Catalogue GOCKU99 (Geosynchronous Objects Catalogue:Kyiv-Uzhgorod 1999) containing topocentric equatorial coordinates and orbital elements of geosynchronous satellites obtained by photographic methods at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine ( MAO NASU ) and at the Space Research Laboratory of Uzhgorod State University (SRL USU) in 1999 is presented. Results of identification of 2445 observations of 140 objects among the total 2570 observations of 169 objects are given. Peculiarities of controlled geosynchronous satellites identification are considered.

   Photographical observations of geosynchronous satellites were performed at MAO NASU and SRL USU in 1999 following the previous surveys (Demchyk et al.1996; Kizyun et al.1998). Total number of identified and unidentified objects for each station is summarized in Table 1.124 various objects are observed in 1999, 35 of them - in two stations.
   The satellite right ascensions RA and declinations D obtained using the observations at MAO NASU reduced using the PPM Star Catalogue in J2000.0 reference frame(Table 2). Time instants are given in the UTC scale.
   Table 3 presents the satellites positions obtained at SRL USU and reduced using the same Catalogue. Time instants are given in the UTC(SU) scale.
   The object name,its COSPAR designation, the object motion type ((c)-controlled satellites,(d)-drifting objects, objects subsatellite longitude L (degree),longitude drift Lt (degree/day), time in MJD scale, i- orbital inclination, W- longitude of the ascending node (degree), u -argument perigee (degree) are provided for the identified objects. There are W(lap),i(lap) for the active satellites with a large orbital inclination (i) and for the passive objects with a large longitude drift. An observations by which an orbital manoeuvre of the satellite is followed is marked by asterisk.

      TABLE  1. NUMBER  OF  GEOSYNCHRONOUS  OBJECTS  DERIVED   BY
                 OBSERVATIONS  IN  KYIV  AND  UZHGOROD  IN 1999
            ______________________________________________________
                      Object type      Kyiv          Uzhgorod
            ______________________________________________________
                                   Identified

                    controlled          61              65
                    drifting            -                7
                  uncontrolled          -                4
                  unknown type          -                3

                                   Unidentified

                    controlled          -                -
                      drifting          -                -
                  uncontrolled          -                5
                  unknown type          19               5

                       Totally          80              89
            ___________________________________________________________

   The identification has been pursued by the orbital inclination, longitude of the ascending node, both reffered to the Laplace plane, objects Greenwich longitude and longitude drift using the method (Kirichenko & Klimik 1994 ).
   Above equator region are the heights where the geostationary satellites are distributed filles up mainly by communication,meteorological satellites and so the satellites for near space investigation. The periodical manoeuvres are need to keep these objects within the limits of +-0.1 degr in longitude. These ones compensate the satellites deviations from the nominal subsatellite point for the various types of satellites perturbations.
   The most observations carried out at MAO NASU and SRL USU are controlled,their subsatellite longitude drift is almost equal zero.
   At first sight the controlled satellites are lightly identified as they "hang" in the same longitudes. But the observations analysis (Demchyk et al.1996; Kizyun et al.1998;Kirichenko et al.1998 ) shown that there are some peculiarities in the identification of these objects and the confident satellites identification impossible without the systematic catalogues of their orbital elements (Log of objects,1999).
   So,at the longitude of (60.0 +-0.1) degr the controlled object is observed and near it - the object 90056A. In 1997 at this longitude have been detected another object with the orbit not diven in catalogues. From 1999 only two unidentified objects have been observed in this region. There is object observed at the longitude 57.0 degr during six years,but this one not given in catalogues too.It may be many examples to take like that.In such case the photometric investigations is desirable to carry out to make sure of the same objects.
    The large deficiency of modern systematic catalogues is that they don't give an information about the transfer of uncontrolled objects in another longitude. So, the object 91003B, observed at SRL before at the longitude 10 degr(E) was observed at the longitude 355.4 degr beginning from July 1999. The object 92041B was observed at the longitude 7 degr(E),but then was transfered of the longitude 10 degr(E).
    Because of damage the instruments at the space objects (the refusal of boundary systems,the orientation disturbance and so on) controlled objects become uncontrolled (passive). After their orbital manoeuvres, these satellites become controlled again. As an example there are two satellites 97070A,Kupon 1 and 99047A, Yamal 1 Table 4.

      TABLE  4.CHANGE OF OBJECT 97070A, KUPON 1 PARAMETERS
__________________________________________________________
  Epoch      Longitude   Drift     i      a       e10-5
   of          degr     degr/day  degr    km
  data
 ________________________________________________________
  7.01.1998   54.20      0.01     0.01    -         -
 13.01.1999   87.89      0.00     0.65  42194.7     9
 18.09.1999   78.29     -0.17     1.17  42178.4    20
  3.01.2000  127.00      0.00     0.02  42166.9   340
_________________________________________________________

   The satellites orbital manoeuvres with a zero orbital inclination (i=0 degr) and withi>1 degr is different. For the first type of objects the subsatellite longitude changes within the limits of +-0.1 arc sec. But, if i>1 degr, the satellite longitude may to change at more large value. The data in Table 5 show as the satellites 99010A, Raduga 1 and 81107A, Fleetsatcom 5 longitudes changes. 99010A satellite manoeuvre took place within MJD 51315.88-51316.87,and for the 81107A object at the moment MJD 51254.99. During the time from MJD 51251.97 to MJD 51375.97 the subsatellite longitude changes almost at 1 degr.
    The satellite orbital elements referred to the Laplace plane are need for the objects identification with a large orbital inclination (Demchyk et al.1996 ). In this case the orbital inclination changes without orbital manoeuvres linearly.

      TABLE  5. CHANGE SOME PARAMETERS OF CONTROLLED OBJECTS
                          99010A AND 81107A
   _________________________________________________________________
               99010A                             81107A
   _________________________________________________________________
      MJD     L       ilap              MJD      L       ilap
             degr     degr                     degr      degr
   _________________________________________________________________
   51251.99  35.2     8.40           51251.97  331.8     6.11
   51315.88  34.7     8.20           51254.99  331.8     6.04
   51316.87  34.7     8.15           51316.94  332.3     6.20
   51375.90  34.8     8.39           51375.97  332.7     6.26
   51376.87  34.8     8.39           51376.93  332.7     6.24
   51434.88  34.8     8.42           51434.96  333.0     6.28
   51436.84  34.9     8.42           51436.91  333.0     6.28
   _________________________________________________________________

    The controlled geostationary satellites having companions,located closer than 0.1 degr, collocated satellites, are difficult to identify, when the orbital manoeuvres occured.
    In Fig.1,2 the collocated satellites positions are given as they obtained using the SBG camera.

• Fig.1,2. Satellites positions for collocated zones

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