SDR-14 Used to copy Mars Phoenix Lander

[fgentges at mindspring.com]

Tom,

The Green Bank antenna area/ 12 Ft Dish area = 744:1

1000:1 is 30 dB in power, 631:1 is 28 Db.  So that is about a 29 dB 
disadvantage our hapless AMRAD member has if he can match the noise 
figure of the Green Bank front end.

If it were a standard NTSC color signal and all we wanted to do was to 
detect was the carrier, we could probably pull it out. Depending on 
transmitter power and the modulation chosen, when the MPL starts sending 
data we might sift out the carrier with a very narrowband filter. I 
doubt there is as much room on the MPL signal as with the NTSC signal.

Frank K0BRA


Tom Azlin, N4ZPT wrote:
> Hi Frank,
> 
> Pat can attest to my reaction when I saw that screen shot.  I sort of 
> said that I had that software and they much have an SDR-14. This was 
> quickly confirmed on the SDR reflectors.
> 
> So just how much path margin would one have with a 12 ft diameter C band 
> dish and a downconverter if we tried to see that 401 MHz signal coming 
> from Mars? That feed was coming from the Green Bank system!
> 
> Fun!
> 
> 73, Tom n4zpt
> 
> fgentges at mindspring.com wrote:
>> tacoistas,
>>
>> An RFSpace SDR-14 was used on the Green Bank 100 meter Radio Telescope 
>> to copy the Mars Phoenix Lander during its descent.  The transmission 
>> copied was on 401.585825 MHz.  The software used was SpectraVue that was 
>> written by Moetronix and supplied by RFSpace.  Details at
>>
>> http://www.rfspace.com/Blog/Entries/2008/5/25_Day_of_longboarding.html
>>
>> This suggests that if you have an old large C band dish sitting around, 
>> you can attach a good RF front end and follow up with something like the 
>> SDR-14 or SDR-IQ you too can copy interesting stuff from space.
>>
>> Frank K0BRA
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