
Radio Meteor Observation Bulletin No. 24                        Aug 1995


1. FORWARD SCATTER METEOR OBSERVATIONS

Observer: Maurice De Meyere
Location: Deurle, Belgium  (3 37' E, 51 00' N)
Frequency: 66.60 MHz 
Transmitter locations:
         Gdansk, PR3,      Poland,   66.29 MHz, 89 kW, distance 1100 km
         Birlad, PR1       Romania,  66.36 MHz, 46 kW
         Sibu, PR1         Romania,  66.44 MHz, 40 kW
         Bucuresti         Romania

Antenna: crossed Yagi, 4 elements, astronomical azimuth 270 o (= East),
         elevation 30 o
         Antenna amplifier: 25 dB  max level  90 dBmuV
Receiver: commercial, Progresson 447A, TESLA, Bratislava
         Sensitivity: 8 muV for S/N = 26 dB  (300 Ohm)
Observing method: automated setup, 150 samples/second,  8 bit resolution.
         [Time and details of all individual meteor reflections are stored on
         file in the University of Ghent format  (Prometeos), and are
         available for further analysis. Reduction software for DOS and
         Windows available].

         Raw counts of reflections with a duration of at least 0.027 s
         during one hour interval starting at UT:


  July |
  1995 |   20h  21   22   23   00   01   02   03   04   05   06
----------------------------------------------------------------
  1- 2 |   16   20   20   27   35   24   33   38   34   28   30
  2- 3 |    /    /    /    /    /    /    /    /    /    /    /
  3- 4 |   21    6   10   11   19   22   33   36   30   32    &
  4- 5 |   10   10   14   24   35   29   33   38   61   32   22
  5- 6 |    4   14   16   25   22   33   42   19   18   24   20
  6- 7 |    -    7   14   15   16   25   30   32   25   30   20
  7- 8 |   12   10    9   19   22   36   32   19   26   21   17
  8- 9 |   27   33   37   58   56   64   56   84?  60   56   59
  9-10 |    -   16   19   37   41   33   44   45  109?  30   32
 10-11 |    -    -    -    -    -    -    -    -    -    -    -
 11-12 |    /    /    /    /    /    /    /    /    /    /    /
 12-13 |    9   13   15   20   18   22   39   29   43   42   34
 13-14 |    /    /    /    /    /    /    /    /    /    /    /
 14-15 |   18    9   20   27   29   39   45   43   41   32   22
 15-16 |    7   11    9   13   21   17   54   32   36   22   15
 16-17 |    &   11   19   21   12   17   22   22   31   20   15
 17-18 |    9    6   12    8    6   20   20   23   17   20   21
 18-19 |   24    8    9   13   13    6   12   20   14    9    8
 19-20 |   11    5    7    8   11   11   20   17   20    8   11
 20-21 |   10    4   19   15   13   14   39   28   26   20   19
 21-22 |   12    6    8    6  115   20    &    &    &    &    &
 22-23 |   19   14    9    7   13   13   29   22   31   21   13
 23-24 |   18   15   15   10   12   23   39   20   34   16   13
 24-25 |   17    7   18   16   13   31   44   55   45   17   30
 25-26 |    9   12    6   14   11   21   27   25   27   23   12
 26-27 |   17    9    9   20   12   55   46   36   19   19   12
 27-28 |    8    5    7   14   15   28   37   63   50   18   30
 28-29 |    -    -    -    -    -    -    -    -    -    -    -
 29-30 |    5   13   14   21   13   23   33   44   35   16   14
 30-31 |   12   96   21   17   17   18   37   26   29   18    7
 31-01 |   10    8   10    7    7   16   23   20   34   11   16
 ------|--------------------------------------------------------
  1995 |   20h  21   22   23   00   01   02   03   04   05   06
  July |


Notes:

 . Some transmitters are not broadcasting between 2h-5h local time
   (Sat-Sun 3h-6h local time) or sometimes longer. (When summer hour is
   in use: local time = UT + 2h).

 . *  sporadic-E
   /  thunderstorms, antenna disconnected
   ?  possibly sporadic-E, to be checked


        Maurice De Meyere / Chris Steyaert


----------------------------------------------------------------------
Observer: Werfried Kuneth, OE8FNK
Location: Villach, Austria (46 37' N, 13 53' E)
Frequency: 59.250 MHz,  SSB mode
Supposed Transmitter locations:
  TV video carrier from Bucarest, distance about 900 km, east.
  Several TV audio carriers (AM?) from Italian Locations in
  Sicilia, Bari and Arezzo, distance 400 to 900 km (all south)
  and possibly other transmitters.

Antenna: dipole with reflector, direction east.
Receiver: AOR AR-8000. No modifications, No preamplifier.
Observing method:
 The audio signal is fed into a real time FFT display (FFTDSP program
 from AF9Y) on the PC where a bandwidth of 2.4 khz is displayed in 2Hz
 steps (in different colors) and stored every 20 minutes.
   All observed carrier frequencies act together like beacons, every meteor
 reflection produces a distinct whistle, which is recorded easily by the
 real time FFT program. Usually there are several different transmitters
 producing visible marks (= meteor reflections) on the display, I count
 only two of them.
   If there are unsufficient transmitters available (usually from 0h00 to
 03h00 UT in the night hours) this is marked with and * (asterix) in the
 table, this means, that the claimed count is (known to be) too low.
   Another situation is marked with an + (plus-sign) when several signals
 are very strong, AGC is active, and no different meteor reflections are
 audible or visible on the spectrum display. This is possibly due to band
 openings or sporadic-E conditions.
   There is a possible deviation where the counts could be wrong. Sometimes
 a transmitter is switched off or "fades out", and I've to count another
 source. Think that the error is now about +/- 10%, but this error will be
 reduced with increasing experience to interpret the "frequency" of the
 incoming meteors directly.
   All the .GIF files are stored on a hard disk for later verification
 (CD-ROM will be available on request).

         Counts in one hour intervals starting at UT:

     |  July July July July July July 1995
  UT |    19   20   21   22   23   24
  ----------------------------------------
  00 |     -    -    -  *15   64  *11
  01 |     -    -    -   *7  *30  *38
  02 |     -    -    -  *15   *0   81
  03 |     -    -    -   97  117   97
  04 |   189  156  114  123  136   96
  05 |   197  148   72    +  136  104
  06 |   183  133    +    -  135  118
  07 |   147  142    +    -  114  123
  08 |   145  142  103    -    -    +
  09 |    78  132   72    -    -   84
  10 |    59    +    +    -    -   90
  11 |    56    +   99    -    -   90
  12 |    63   97    +    -    -   96
  13 |   156  150    +    -    -  108
  14 |     -    -    +    -    -  123
  15 |     -    -    +    -    -  105
  16 |     -    -    +    -    -    +
  17 |     -    -    +    -    -    -
  18 |     -    -    +    -   99    -
  19 |     -    -   -     -  118    -
  20 |     -    -   -     -  165    -
  21 |     -    -   68  150  107
  22 |     -    -   55  116   95
  23 |   123    -   45   73   56
  ----------------------------------------
  UT |    19   20   21   22   23   24
     |  July July July July July July 1995

---------------------------------------------------------------------
Observer:  Ilkka Yrjola
Location:  Finland  (26 35' E, 60 54' N)
Frequency: 87.360 MHz
Receiver: narrow band FM, detected signal level >-122dBm.
Antenna: 2 element Yagi with 4dBd gain to SW.
Antenna Azimuth:  45 o
Computer: T-1000SE
Data sampling system: threshold crossing detection is fed in binary
  form (1 bit) from the receiver, to the computer.
  Computer logs total hourly elapsed reflection time, number of
  threshold crossings for the hour, the longest time the signal was
  continuously above detection level for the hour.

  Data stored in the Compact MS-Soft format. Software for viewing available
  from FTP.FUNET.FI  pub/ham/vhf-work/mssoft42.zip

                 delta Aquarids and Capricornids 1995

      Number of threshold crossings for the hour starting at:


   UT  | 27 Jul   28 Jul   29 Jul   30 Jul
   ---------------------------------------
    0  |    487      517      446      514
    1  |    468      652      485      608
    2  |    458      447      500      563
    3  |    455      412      423      508
    4  |    489      410      342      480
    5  |    313      281      309      367
    6  |    345      348      304      292
    7  |    293      278      270      292
    8  |    325      259      300      311
    9  |    316      308      278      236
   10  |    205      213      263      196
   11  |    247      221      245      209
   12  |    212      185      247      165
   13  |    209      164      311      203
   14  |    212      172      203      160
   15  |    179      178      186      152
   16  |    162      159      165      116
   17  |    227      157      177      126
   18  |    158      180      186      139
   19  |    164      164      172      156
   20  |    157      148      255      187
   21  |    240      236      293      419
   22  |    363      292      375      407
   23  |    494      439      428      494
   ---------------------------------------
   UT  | 27 Jul   28 Jul   29 Jul   30 Jul

    Ilkka Yrjola / via M. De Meyere


2. FOR SALE

  Fluke 6071A Synthesiser RF signal generator
  continously from 200 kHz to 1040 MHz
  AM/FM modulation  (internal/external)
  modulation frequency  20 Hz / 20 kHz
  output  -150 dB / + 20 dB
  fully digital
  with IEEE output

  Contact: Benny Croonen, tel +32 (11) 54 68 97  or e-mail via C. Steyaert

  This is a professional piece of equipment, hence it is not cheap.
  Until it has not been sold: possibility to calibrate your receiver
  for a fee (if you can make it to Lommel, Belgium...)


3. ABOUT THE RMOB

The RMOB is an independent initiative of some workers in the field of radio
meteor scatter observations and data reduction. It started in August 1993
in order to spread rapidly the Perseid results via E-mail. Since then, it
has appeared monthly, and has gradually been expanded.

Typically it contains: summaries of recent observations, first results of
stream activity by radio methods, relations between radio and optical
meteors, references to other publications in the field of meteor astronomy
and radio scatter techniques, announcements of meetings, short questions and
answers, non-commercial (second hand) sale of radio equipment, available
software.

Contributors are mentioned, and interested persons are asked to contact them
directly.

RMOB can be copied freely in unabridged and unmodified form. Extracts should
indicate the source (Radio Meteor Obs Bulletin, month and year).

If you want to subscribe (or unsubscribe) to the E-mail distribution list,
please send a message to C. Steyaert.
Those not having access to E-mail can obtain a printed copy free of charge
from J. Van Wassenhove (current or back-issues).


4. CONTRIBUTORS / USEFUL ADDRESSES

Thomas Ashcraft
Santa Fe, New Mexico
E-mail: 72632.1427@compuserve.com

Maurice De Meyere
Hullekensstraat 24, B 9831 Deurle, Belgium
tel: +32 (9) 282 35 26
Call: ON4NU,  packet: ON4NU@ON4AWP
E-mail: via Chris Steyaert

Werfried Kuneth
Villach, Austria
Call: OE8FNK

Chris Steyaert, VVS
Kruisven 66, B 2400 Mol, Belgium
tel: +32 (14) 31 51 04
fax: +32 (14) 22 13 73
E-mail: steyaert@vvs.innet.be
Compuserve: 72650,3513

Jeroen Van Wassenhove, VVS
's Gravenstraat 66, B 9810 Nazareth, Belgium
tel: +32 (9) 385 61 09
E-mail: 100101.734@compuserve.com

Paul Vauterin, University of Ghent, Astronomical Observatory
E-mail: paul@izar.rug.ac.be

Ilkka Yrjola
Jukolantie 16
SF 45700 Kuusankoski, Finland
tel: +358 (951)402 2797
Call: OH51Y
E-mail: ILKKA.YRJOLA@915000.KY.KYMMENE.MEMONET.mailnet.fi

--
Christian Steyaert            (RMOB9507)                         11 Aug 1995
--
