Results of the IMO Video Meteor Network - September 2006
========================================================
Describing the observing results of September I'm running out of superlatives.
We experienced already a number of successful months in the history of the
camera network, but the last one outshined everything we had before.
Let's start with the observers. In September 2006, 14 observers operated 19
video cameras. Beware that the data of Times5, Times6 (BENOR) and Remo1
(MOLSI) are not yet gathered.
Thanks to the perfect weather in central Europe, up to 14 cameras were active
in the same night, and there are two nights were we could collect more than
100 hours of effective observing time. Six observers managed to observe in 20
or more nights!
Last October I thought that the fresh record of 1500 hours of observing time
would be hard to beat. Well, the available data set from last month sums up
to more than 1750 hours, and together with the three missing cameras it could
be up to almost 2000. That would be twice as much as in the whole first year
of the camera network.
The meteor number was 50% higher than in the best September so far.
To keep the long story short: The golden September 2006 was very favourable
to the video observers, who did not let the chance slip.
What else to report? Bob Lunsford demonstrated how far a good observing site
can influence the outcome when operating an image-intensified camera. On
September 1 he observed from a really dark site at Mt. Laguna. Within 3.5 hours
he managed to record a blazing 150 meteors. I checked the observation - they
are all real. :-) In the remaining part of the month he observed from his
primary, more light polluted site. There he recorded well below half the
number of meteors in more than 8 hours.
As mentioned in the last report, together with Pavel Spurny from Ondrejov
Observatory I could do some detailed analysis of the accuracy of wide angle
video recordings (Mintron camera with 6mm f/0.8 lens) based on a fireball
record from August 15.
The first results were disastrous. A closer inspection revealed three errors:
- The automatically measured positions had a fixed offset, since the camera
was not perfectly fixed. It had shifted by 1/2 deg since the last measurement
of reference stars.
- At the time of maximum meteor brightness, the were huge position errors
since not the center of the fireball shutter break was measured, but the
leading point of the meteor along the trail.
- At the end the fireball moved outside the field of view, but MetRec still
detected the persistent train for a short time. In this part of the trajectory,
the error naturally increased incrementally.
After the shutter break positions of the video record were manually corrected,
the result was much better.
A detailed analysis yielded the following results:
- The deviation of individual video meteor positions from the average
trajectory computed from all photographic records was about 120 m. It was by
a factor of five larger than the scatter of the photographic measurements.
This comes as no surprise, since the resolution of the video camera was 9'
per pixel, compared to 1/2' resolution of the photographic fisheye cameras.
- Due to the higher sensitivity, the video camera detected the fireball more
than one second earlier, which in this case translates to an altitude
difference of 6 km (80 vs. 74 km).
- The photographic brightness was several magnitudes brighter than the one
determined by MetRec (-8 vs. -4 mag). It has to be remembered, though, that
there are no reference stars in the given magnitude range such that the video
brightness needed to be extrapolated over several magnitudes.
- Even though the image of bright objects is heavily distorted (coma) when
using asperical Computar lenses, the position is still quite accurate when
estimating the center of the shutter breaks. The deviation of the video data
from the photographic trajectory increased only little at the time of
maximum brightness.
- The velocity determined from the video recording showed a much larger scatter
from frame to frame than the photographic measurements.
It can be concluded, that wide-angle video data are less accurate than the
fisheye cameras from the EN due to the lower resolution, but they can still be
used for trajectory determination. It is vital to work accurately and rule
out systematic errors. The mentioned deviation by 1/2 degree shifted the
trajectory systematically by a few hundred meters. An addition, video position
measurements of bright fireball need to be verified and corrected manually.
1. Observers
============
Code Name Place Camera FOV LM Nights Time Meteors
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CASFL Castellani Monte Baldo BMH1 (0.8/6) 55 dg 3 mag 15 98.1 h 262
ELTMA Eltri Venezia MET38 (0.8/3.8) 80 dg 3 mag 4 35.6 h 143
EVAST Evans Moreton RF1 (0.8/12) 25 dg 5 mag 10 69.3 h 262
HINWO Hinz Brannenburg AKM2 (0.85/25) 32 dg 5 mag 13 97.4 h 672
KACJA Kac Kostanjevec METKA (0.8/8) 42 dg 2 mag 23 112.7 h 200
Kamnik REZIKA (0.8/6) 55 dg 3 mag 18 109.3 h 471
KOSDE Koschny Noordwijkerh. ICC3 (0.85/25) 25 dg 5 mag 1 5.7 h 52
LUNRO Lunsford Chula Vista BOCAM (1.4/50) 60 dg 6 mag 21 119.3 h 855
MOLSI Molau Seysdorf AVIS2 (1.4/50) 60 dg 6 mag 18 92.1 h 1558
MINCAM1 (0.8/6) 55 dg 3 mag 27 159.9 h 513
SLAST Slavec Ljubljana KAYAK1 (1.8/28) 50 dg 4 mag 20 94.4 h 172
SPEUL Sperberg Salzwedel AKM1 (0.85/2) 32 dg 5 mag 3 22.3 h 61
STOEN Stomeo Scorze MIN38 (0.8/3.8) 80 dg 3 mag 8 54.6 h 163
STRJO Strunk Leopoldshoehe MINCAM2 (0.8/6) 55 dg 3 mag 27 161.8 h 396
MINCAM3 (0.8/8) 42 dg 4 mag 17 129.8 h 438
MINCAM4 (1.4/2) 180 dg 0 mag 5 45.9 h 25
MINCAM5 (0.8/6) 55 dg 3 mag 13 99.5 h 527
TRIMI Triglav Velenje SRAKA (0.8/6) 55 dg 3 mag 26 134.8 h 429
YRJIL Yrjola Kuusankoski FINEXCAM (0.8/6) 55 dg 3 mag 19 111.8 h 672
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Sum 30 1754.3 h 7871
2. Observing Times (h)
======================
Sep 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
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CASFL 8.4 3.9 8.5 8.5 8.1 3.5 - 4.5 8.9 5.8 8.6 9.3 4.3 - -
ELTRI 8.1 - - - - - - - - - - - 8.4 - -
EVAST - - 7.4 - - - 7.9 8.7 - 8.6 - - - - -
HINWO 7.7 - - - - - - 8.5 8.7 6.4 8.4 7.4 8.1 - -
KACJA 8.7 4.2 8.8 5.4 2.5 2.3 2.1 5.0 7.2 1.3 5.0 6.2 2.5 - -
8.9 - 9.1 0.3 7.1 1.4 - - 5.6 - 8.8 5.6 8.1 - -
KOSDE - - - - - - - - - - - - - - -
LUNRO 3.5 8.6 8.1 6.6 3.7 4.7 3.0 1.7 - 5.6 8.1 7.1 5.5 - -
MOLSI 5.2 - 0.7 3.5 6.0 - - 8.2 7.7 3.3 - - - - -
5.6 0.4 2.2 5.7 9.3 7.4 0.6 9.5 9.6 5.6 9.7 9.8 9.8 4.9 1.6
SLAST - 3.4 8.1 8.0 6.4 2.4 - 3.5 6.0 3.0 3.0 6.0 - - -
SPEUL - - - - - - - - - - - - - 5.0 -
STOEN 7.9 5.5 - - 6.1 - - - - 1.8 - 8.6 6.8 - -
STRJO 1.2 - 0.8 8.3 0.5 8.4 3.2 8.5 8.6 7.2 8.7 8.8 8.9 7.7 0.5
- - - 8.2 - 4.1 0.8 6.3 8.5 8.7 8.8 8.7 8.9 9.0 -
- - - - - - - - - - - - 8.9 9.0 -
- - 1.1 8.2 - 8.3 0.7 8.7 8.6 8.6 8.8 8.7 9.0 - -
TRIMI 7.0 7.0 7.0 7.0 1.5 2.2 1.7 4.8 6.7 6.6 5.7 7.0 7.0 0.5 -
YRJIL 4.3 0.6 1.5 - - 4.6 - - - 7.1 4.5 4.9 6.0 8.1 8.2
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Sum 76.5 33.6 63.3 69.7 51.2 49.3 20.0 77.9 86.1 79.6 88.1 98.1102.2 44.2 10.3
Sep 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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CASFL - - - - - - - 7.3 - - 4.0 4.5 - - -
ELTRI - - - - - - - 9.5 - - - 9.6 - - -
EVAST - - - 7.8 9.0 - 8.4 - 3.6 2.6 - - - 5.3 -
HINWO - - - - 9.2 - 7.9 9.6 6.0 - - - 7.8 1.7 -
KACJA - - - - 4.2 1.7 3.0 6.4 8.6 6.6 - 2.6 4.0 7.8 6.6
- - - 1.1 4.0 5.7 9.6 - 5.6 8.0 - 2.3 9.6 8.5 -
KOSDE - - - - - 5.7 - - - - - - - - -
LUNRO - 6.0 9.9 7.5 2.8 1.2 2.6 - 10.1 - - - 8.0 - 5.0
MOLSI - 3.2 - - 5.4 7.2 9.6 9.3 5.9 2.8 - 2.0 5.1 6.5 0.5
5.6 5.6 - 0.7 10.2 10.0 10.4 10.4 6.2 3.0 - 0.6 1.2 4.3 -
SLAST - - - 1.0 4.7 - - 8.7 6.7 2.0 8.4 5.4 2.1 4.3 1.3
SPEUL - - - - - 8.6 - - 8.7 - - - - - -
STOEN - - - - - - - - - - 9.4 8.5 - - -
STRJO 6.2 0.5 - 7.4 9.4 9.6 9.6 9.6 9.7 - 0.5 3.0 6.2 2.0 6.8
9.0 - - 1.3 9.4 9.6 9.4 9.5 9.6 - - - - - -
9.1 - - - 9.4 9.5 - - - - - - - - -
- - - - - - - 9.4 9.6 - - - - - 9.8
TRIMI - - - 0.2 7.0 5.0 1.1 4.8 7.8 7.0 5.5 5.8 7.9 7.0 4.0
YRJIL 8.0 6.5 3.3 - 8.5 - 8.8 8.9 - 8.2 8.3 1.5 - - -
--------------------------------------------------------------------------------
Sum 37.9 21.8 13.2 27.0 93.2 73.8 80.4103.4 98.1 40.2 36.1 45.8 51.9 47.4 34.0
3. Results (Meteors)
====================
Sep 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
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CASFL 25 6 24 33 21 5 - 10 34 18 15 20 7 - -
ELTRI 41 - - - - - - - - - - - 28 - -
EVAST - - 15 - - - 35 37 - 25 - - - - -
HINWO 44 - - - - - - 40 77 29 46 41 77 - -
KACJA 12 11 13 8 4 5 6 12 16 1 10 8 8 - -
45 - 46 2 25 3 - - 41 - 30 19 39 - -
KOSDE - - - - - - - - - - - - - - -
LUNRO 150 74 39 35 13 10 7 2 - 24 38 42 27 - -
MOLSI 91 - 6 47 115 - - 80 116 45 - - - - -
18 2 7 24 50 28 3 35 52 10 35 29 33 17 8
SLAST - 5 19 26 13 1 - 5 9 3 4 11 - - -
SPEUL - - - - - - - - - - - - - 12 -
STOEN 24 13 - - 12 - - - - 2 - 26 21 - -
STRJO 5 - 2 22 1 17 12 21 26 9 24 19 19 18 1
- - - 24 - 10 3 28 32 19 23 30 39 33 -
- - - - - - - - - - - - 4 8 -
- - 3 49 - 23 1 58 52 35 50 45 44 - -
TRIMI 32 26 33 22 3 3 4 11 24 25 17 20 18 2 -
YRJIL 32 1 2 - - 40 - - - 44 16 30 35 61 76
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Sum 519 138 209 292 257 145 71 339 479 289 308 340 399 151 85
Sep 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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CASFL - - - - - - - 28 - - 7 9 - - -
ELTRI - - - - - - - 36 - - - 38 - - -
EVAST - - - 29 41 - 25 - 8 9 - - - 38 -
HINWO - - - - 73 - 63 82 23 - - - 68 9 -
KACJA - - - - 14 4 4 5 14 12 - 4 7 13 9
- - - 10 10 25 42 - 31 16 - 2 40 45 -
KOSDE - - - - - 52 - - - - - - - - -
LUNRO - 39 100 69 9 4 4 - 88 - - - 58 - 23
MOLSI - 44 - - 141 165 211 254 85 18 - 16 52 69 3
16 6 - 1 14 30 30 38 8 4 - 2 3 10 -
SLAST - - - 1 11 - - 15 7 1 24 5 6 5 1
SPEUL - - - - - 21 - - 28 - - - - - -
STOEN - - - - - - - - - - 32 33 - - -
STRJO 12 1 - 14 17 25 24 14 29 - 2 12 16 6 28
30 - - 3 40 40 24 22 38 - - - - - -
5 - - - 5 3 - - - - - - - - -
- - - - - - - 48 71 - - - - - 48
TRIMI - - - 1 20 11 3 17 24 13 23 14 26 28 9
YRJIL 65 40 12 - 77 - 42 68 - 16 13 2 - - -
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Sum 128 130 112 128 472 380 472 627 454 89 101 137 276 223 121
Sirko Molau, 2006/10/19