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By Bruce McCurdy

The following Geminid results were manually transcribed from the Northern Claw Radio Meteor Observatory (that would be the one in my basement) which does passive detection of meteors on FM 92.1 MHz using a 3-element Yagi antenna and Radio SkyPipe software. Reception was very consistent over the five-day period recorded, with peak activity clearly occurring on December 14 UT and a surprisingly rapid descent on the 15th. (Is this normal?)

I have two different predictions at my disposal re: the peak: the RASC Observer's Handbook projected 4h UT, Gary Kronk's (great!) website suggested 1510 UT, both on the 14th. I would conclude from my data that the peak was sometime fairly early on the 14th UT, as results for the evening hours of the 13th (MST) were much higher than the equivalent period on the 14th MST. This is reflected in the significantly different curve for the Mean Hourly Rate calculated for each calendar date UT v. MST, as recorded on the bottom two lines.

I also recorded the mean hourly rate for each hour on the extreme right column. The diurnal rise and fall is clearly apparent: here at +53°33' N, 113°33' W, the radiant transits around 0230 MST (0930 UT), and sets below the northern horizon from roughly 1230-1630 MST (1930-2330 UT). Indeed, the few "hits" I had during this four hour block featured a number of the biggest spikes anywhere on my charts, suggesting some sort of spurious mid-day local source. In addition, my evening counts were actually low as I heard quite a number of hits which were obvious to the ear as signal instead of static, but which were at similar volume levels and therefore did not show up as spikes. So the diurnal data which shows meteor hits in the overnight hours as being some ten times the rate as the mid-day hours is, if anything, moderate. 

UT   MST  | 12/11  12/12 12/13  12/14  12/15  | Total Mean HR

_____________________________________________________________
 0    -7  |   10     9      9     22      8   |   58     12
 1    -6  |    8     8     13     28     21   |   78     16
 2    -5  |   12     9     22     48     19   |  110     22
 3    -4  |   22    33     39     77     34   |  205     41
 4    -3  |   25    28     41    104     47   |  245     49
 5    -2  |   32    37     53    109     43   |  274     55
 6    -1  |   37    27     83     87    null  |  234     59
 7     0  |   33    34     80    111     18   |  276     55
 8     1  |   24    41     77     97     26   |  265     53
 9     2  |   25    43     74    105     22   |  269     54
10     3  |   32    46     73    119     18   |  288     58
11     4  |   26    34     43     81     28   |  212     42
12     5  |   13    29    null    83     14   |  139     35
13     6  |   20    27     57     63     13   |  180     36
14     7  |   20    31     52     49     11   |  163     33
15     8  |   17    22     24     47     21   |  131     26
16     9  |    9    18     31     38     16   |  112     22
17    10  |    7    19     18     18      4   |   66     13
18    11  |   14    12      8     23      4   |   61     12
19    12  |   12    12     10      8      8   |   50     10
20    13  |   10     5      5      2      3   |   25      5
21    14  |    4     6      9      2      2   |   23      5
22    15  |    4    12      4      7      5   |   32      6
23    16  |    8     6      8      9      6   |   37      7
____________________________________________________________

Daily Total   424   548    833   1337    391
Mean  HR (UT)  18    23     36     56     17
***
Mean  HR (MST) 18    27     46     45     12

             12/11 12/12  12/13  12/14  12/15