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 --