(meteorobs) Perseids from Switzerland

[Geert Barentsen]

Hi Marco,

Thanks for your mail. I will demo my ZHR machinery at the IMC. The analysis 
is done with functions inside a PostgreSQL-database, largely based on 
Rainer Arlt's article in the 2004 IMC proceedings.

You are right about the high ZHR's. Our limiting magnitudes have been 
systematically underestimated for the past 10 year. I have wondered about 
this a lot because we do everything right (e.g. count in at least 3 or 4 
fields, make sure the fields are at sufficient elevation, take Lm-gaps and 
negative outliers into account, etc...)

My best guess is that our Lm's would be higher if we practiced more under 
really good skies. We mainly observe in the vicinity of Antwerp, Belgium, 
where skies are _extremely_ poor. We could do a test at the IMC.

Geert



At 12:10 24-8-2005, you wrote:


>Geert Barentsen wrote:
>>Hi there,
>>Our Belgian youth group gathered around 4044 Perseids in 229h Teff at our 
>>astronomy camp in Switzerland.  I generated a ZHR graph tonight using 
>>free software (postgresql and gnuplot). Nothing spectacular, but I 
>>thought I'd share the result: http://www.urania.be/oberon/per2005e.pdf
>>(PDF graph)
>>Greetings,
>>Geert
>
>Hi Geert,
>
>Nice graph and nice (and large!) continuous dataset! Well done!
>
>A few of my thoughts after looking at your graph: the ZHR's come out 
>slightly on the high side for all nights concerned. This could be due to 
>either not taking into account personal perceptions in the reduction, or 
>systematic underestimate of the limiting magnitude in the data (the latter 
>often happens with e.g. novice observers).
>
>I have been working on a ZHR calculation program lately which might be 
>useful to you and others. A first version can be downloaded at:
>
>  http://home.wanadoo.nl/marco.langbroek/lamasoft.html
>
>It is a DOS console program (sorry, no yet fluent enough in C++ to make a 
>windows environment...) which will open a DOS console window when you 
>click the .exe. It reads observational data from a .txt file and after a 
>short dialogue where you can set parameters, outputs a table to the screen 
>and to a text file written to your harddisc. Apart from ZHR values it also 
>outputs the solar longitude, radiant altitude etc.
>
>First read the README.txt before you start using it, as this file contains 
>the instructions on the input file format, how to operate the program etc.
>
>- Marco  :-)
>
>-----
>Dr Marco Langbroek
>Dutch Meteor Society (DMS)
>
>e-mail: meteorites at dmsweb.org
>private website http://home.wanadoo.nl/marco.langbroek
>DMS website http://www.dmsweb.org
>-----
>---
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