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
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
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    -    -    -
--------------------------------------------------------------------------------
Sum   128  130  112  128  472  380  472  627  454   89  101  137  276  223  121

Sirko Molau, 2006/10/19