----- Original Message ----- From: "James R Miller" <g3...@jrmiller.demon.co.uk> To: <domenico.i8...@tin.it> Cc: <peter.guel...@kourou.de> Sent: Monday, November 28, 2011 1:57 AM Subject: Re: Fw: [amsat-bb] AMSAT-DL Hears Mars Science Laboratory X-Band Downlink
> Dear Domenico, > > > I was really impressed reading your report about receiving the > > MSL beacon of MSL on the following page: > > Thank you! > > It is not difficult; we receive lots of the NASA spacecraft all the time. > Stereo-A/B every day, and when they have gone LOS, we (I) check Grail-A > and Grail-B and also Juno. When Juno was new, the signal was huge, and > enabled the beam shape to be determined with greater depth than before. > > Grail-A/B have very high performance Ultra Stable Oscillators (USO) and > they are free running. A daily check allows us to check independently > that our own station oscillators remain in accurately lock. > > Reception of MSL required adding its trajectory data to the spacecraft > database, and the frequency to the radio control computer. Provided the > given frequency is with +/- 40 kHz of the actual frequency, we can lock > onto it in 1 sec via an FFT acquisition process. As it happens, the > actual frequency was within 8 kHz of the DSN channel centre, so finding it > was immediate. > > The station computers can be remotely accessed from home to do software > maintenance jobs. Hardware requires people to go to the site, of course. > Remote software management is probably the most important part of this > story. > > Article about telescope systems: > http://www.amsat.org/amsat/articles/g3ruh/126.html > > Article about Stereo A/B reception: > http://www.amsat.org/amsat/articles/g3ruh/127.html > > Hoping you are in good health. Wish I was in Italy for the winter! > > 73 de James G3RUH > > -- > ========================================================================== > James R Miller WWW/PGP: http://www.jrmiller.demon.co.uk/ > Cambridge, England Stardate: 2011 Nov 28 [Mon] 0053 utc > ========================================================================== HI Peter, DB2OS and James, G3RUH I was really impressed reading your report about receiving the MSL beacon of MSL on the following page: http://tinyurl.com/7t5xjwk Congrats to you Peter and James , I am sure that in the future AMSAT-DL will be able to launch P3-E and P5-A Thanks also to JoAnne K9JKM for providing us with the above information. 73" de i8CVS Domenico _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
