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Re: Further AO-10 Observations On Perigee Passes



    AO-10 currently experiences eclipses at perigee of approximately 30 minutes
    length.  The one tonight should start at 00:37:34 UTC (MA = 255) and end at
    01:07:08 UTC (MA = 30).  During this time there should be complete loss of
    signal.  What Jerry is describing above appears to be a different
    phenomenon related to slow tumbling of the satellite producing poor
    illumination of the solar panels, poor antenna positioning, or both.
    However, please note that the perigee eclipses will continue for a long
    time (months). They will slowly move towards a later period in the orbit
    and a corresponding longer duration into the early part of 2000. For
    example, by 2000/03/01, the eclipses will have moved to MA 45-72 and will
    be 75 minutes long.  AO-10 won't be "eclipse free" again until March 25, 2000.

Attached are predictions for the coming week for portions of passes which
are near-perigee passes (e.g. < 157 dB loss) and not in eclipse.  K5OE has
noted a pass that wasn't on either coast, so i've included Texas as well as
both coasts in this set.

This coming week looks particularly favorable for west of the Mississippi
in terms of distance, but on the West Coast, most of the passes are in
the middle of the night.  Otherwise, it's mostly a matter of getting up
early enough.  I'll try to get up early (6am PDT) tomorrow (Saturday) and
maybe Sunday (5am).

Analogous to EME operation, i hope some of the 'big guns' will be out there
with their excellent receiving equipment to work some of us penny-whistle
stations.  I heard England from California on a four element-pair LPVA 
the last time i tried this(!), so your presence is especially appreciated.

                                -- KD6PAG

-------------------------------------------------------------------------------
KD6PAG SatTrack V3.1 Prediction Summary (sunlit LEO passes)

Satellite #14129  : AO-10 (OSCAR 10)
Data File         : tlex.dat
Element Set Number: 594 (Orbit 9463)
Element Set Epoch : 02Oct99  15:06:15.703 UTC   (20.1 days ago)
Orbit Geometry    : 4004.91 km x 35447.61 km at 27.190 deg
Propagation Model : TLE Mean
Ground Station    : Berkeley (SSL), CA, USA   ---   CM87VV
Time Zone         : UTC (+0.00 h)
Downlink Frequency: 145.9000 MHz

   UTC    Azimuth  Elev    Range  Sun Ang  Doppler  Loss  Phs Md V
           [deg]  [deg]     [km]    [deg]   [kHz]   [dB]

Sat  23Oct99  ---  Orbit 9507

13:02:43   248.0   52.4   9736.6     40.0   -0.90  155.5   15  B V
13:13:43   231.0   65.9  11213.5     58.3   -1.23  156.7   19  B V

Sun  24Oct99  ---  Orbit 9509

12:13:24   245.6   47.8   8463.7     25.4   -0.60  154.3   12  B V
12:35:24   189.3   73.4  11498.3     65.2   -1.40  156.9   20  B V

Mon  25Oct99  ---  Orbit 9511

11:26:50   240.0   45.4   7621.2     15.5   -0.36  153.4   10  B V
11:51:35   155.5   72.0  11027.7     64.9   -1.50  156.6   19  B V

Tue  26Oct99  ---  Orbit 9513

10:45:46   222.7   55.0   7197.8     19.8   -0.62  152.9   10  B V
11:10:31   126.2   64.7  11210.2     68.1   -1.62  156.7   19  B V

Wed  27Oct99  ---  Orbit 9515

10:07:27   181.0   65.0   7321.8     32.4   -1.15  153.0   11  B V
10:26:42   113.7   57.0  10980.5     67.6   -1.71  156.5   18  B V

Thu  28Oct99  ---  Orbit 9517

09:26:23   147.5   61.3   7410.8     37.7   -1.41  153.1   11  B V
09:45:38   102.9   46.8  11449.0     70.1   -1.80  156.9   18  B V

Fri  29Oct99  ---  Orbit 9519

08:45:20   125.3   52.6   7706.9     42.5   -1.63  153.5   11  B V
09:01:50    97.2   38.7  11405.4     68.8   -1.88  156.9   17  B V

Sat  30Oct99  ---  Orbit 9521

08:05:34   108.8   41.1   8473.1     48.8   -1.84  154.3   12  B V
08:16:34    93.9   31.9  11071.0     65.3   -1.94  156.6   16  B V


Satellite #14129  : AO-10 (OSCAR 10)
Data File         : tlex.dat
Element Set Number: 594 (Orbit 9463)
Element Set Epoch : 02Oct99  15:06:15.703 UTC   (20.2 days ago)
Orbit Geometry    : 4004.91 km x 35447.61 km at 27.190 deg
Propagation Model : TLE Mean
Ground Station    : Dallas, TX, USA   ---   EM12OS
Time Zone         : UTC (+0.00 h)
Downlink Frequency: 145.9000 MHz

   UTC    Azimuth  Elev    Range  Sun Ang  Doppler  Loss  Phs Md V
           [deg]  [deg]     [km]    [deg]   [kHz]   [dB]

Fri  22Oct99  ---  Orbit 9505

(Actually following day in UTC)
00:10:53   180.0    3.9  11375.0     99.1   +1.41  156.8  245  B D
00:16:23   170.7    3.1  10475.2     89.1   +1.23  156.1  247  B V

Sat  23Oct99  ---  Orbit 9507

12:51:06   278.6    5.6  11096.8      9.8   +0.06  156.6   11  B D
13:02:06   275.5   24.0  11424.2     30.2   -0.51  156.9   15  B D

Mon  25Oct99  ---  Orbit 9511

11:48:13   260.7   57.4  10876.6     47.9   -1.04  156.5   18  B V
11:50:58   258.5   60.9  11241.5     52.1   -1.11  156.7   19  B V

Tue  26Oct99  ---  Orbit 9513

10:58:54   258.1   56.7   9402.1     36.2   -0.90  155.2   15  B V
11:12:39   237.7   75.0  11329.9     59.2   -1.30  156.8   20  B V

Wed  27Oct99  ---  Orbit 9515

10:12:20   252.3   58.3   8356.2     27.9   -0.80  154.2   13  B V
10:31:35   177.7   81.4  11222.4     62.7   -1.43  156.7   20  B V

Thu  28Oct99  ---  Orbit 9517

09:28:31   240.5   64.4   7678.0     25.6   -0.86  153.4   12  B V
09:50:31   120.8   74.5  11312.4     66.2   -1.56  156.8   20  B V

Fri  29Oct99  ---  Orbit 9519

08:44:42   221.8   69.1   7093.6     23.5   -0.92  152.7   11  B V
09:06:42   106.1   65.7  11025.6     66.1   -1.67  156.6   19  B V

Sat  30Oct99  ---  Orbit 9521

08:03:38   172.3   73.7   6991.1     29.5   -1.24  152.6   11  B V
08:25:38    96.7   54.1  11441.5     69.1   -1.77  156.9   19  B V


Satellite #14129  : AO-10 (OSCAR 10)
Data File         : tlex.dat
Element Set Number: 594 (Orbit 9463)
Element Set Epoch : 02Oct99  15:06:15.703 UTC   (20.1 days ago)
Orbit Geometry    : 4004.91 km x 35447.61 km at 27.190 deg
Propagation Model : TLE Mean
Ground Station    : New York, NY, USA   ---   FN30AS
Time Zone         : UTC (+0.00 h)
Downlink Frequency: 145.9000 MHz

   UTC    Azimuth  Elev    Range  Sun Ang  Doppler  Loss  Phs Md V
           [deg]  [deg]     [km]    [deg]   [kHz]   [dB]

Mon  25Oct99  ---  Orbit 9511

11:29:02   275.8    3.3  11333.3     12.1   +0.01  156.8   11  B D
11:34:32   272.9   12.3  11427.0     20.8   -0.28  156.9   13  B D

Wed  27Oct99  ---  Orbit 9515

10:23:24   250.3   46.3  10886.3     41.7   -0.93  156.5   17  B V
10:26:09   247.4   49.6  11217.0     46.1   -1.02  156.7   18  B V

Thu  28Oct99  ---  Orbit 9517

09:36:50   245.1   48.1   9771.4     34.2   -0.85  155.5   15  B V
09:47:50   228.2   61.2  11199.7     52.7   -1.21  156.7   19  B V

Fri  29Oct99  ---  Orbit 9519

08:47:31   243.5   42.8   8549.0     19.6   -0.52  154.4   12  B V
09:09:31   194.3   68.6  11446.5     59.4   -1.38  156.9   20  B V

Sat  30Oct99  ---  Orbit 9521

08:03:42   234.2   46.3   7883.1     16.6   -0.50  153.7   11  B V
08:28:27   159.4   68.0  11448.3     62.5   -1.50  156.9   20  B V

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