[amsat-bb] Re: testing the grey line theory

john heath g7hia at btinternet.com
Sat Oct 13 14:32:11 PDT 2007


Thanks to Garie for the LUSAT data which decodes to 20.1Volts from the solar 
panels on the +Z (top) face of the satellite.

Mike Ruprecht DK3WN has a neat telemetry utility on his web site. Type in 
the letter groups and read off the corresponding values.
Thanks Mike, I use this a lot.  www.mike-rupprecht.de   ( hope its still on 
the site I downloaded it in 2006)

The Grey Line idea  I had in mind was to take a series of values for +Z as 
the satellite passed from darkness, across the grey line then into sunlight.
Compare these with the position of the greyline shown on a tracking program.

I see two obvious flaws in the idea. The telemetry from Lusat is not 
continious so there are short gaps in the data.
The unknown time delay between the spacecraft software capturing the voltage 
value and transmitting it.

AO-51 has much more sophisticated telemetry data so perhaps this is a good 
experiment to try on AO-51,  when the soundcard software is released.
As far I can tell the currently available telemetry software only works with 
the output from a hardware modem (expensive).

BTW - you can see the grey line in space. Watch a visual of the ISS going 
West to East in the evening. The ISS is very bright near TCA and as it gets 
into the East the brightness diminishes, goes through a dull orange colour, 
then dissapears into the darkness.

73 John G7HIA

More information about the AMSAT-BB mailing list