NH transmission times? Options

[pjm]

Hi folks,

I'm wondering if anyone here knows specifics of transmission times from the NH space craft to DSN tracking stations? There is some vague information on the JPL RAPWEB pages about long range forcasts of DSN resource useage, but nothing specific about start / end days and times. Even though NH is fairly far away, it should be possible to detect signals from it, whilst its less than a couple of hundred million miles from Earth.

regards,

Paul.
contributor to http://www.uhf-satcom.com

[RNeuhaus]

Why are you interested to catch any NH's signaling? Theirs are only useful for the John Hopkins Applied Physics Laboratory and nothing else.

Rodolfo

[Bob Shaw]

Rodolfo:

I think, basically, you'll find that it's 'cos he *can*! And wouldn't *you*?

Bob Shaw

[RNeuhaus]

Rodolfo:

I think, basically, you'll find that it's 'cos he *can*! And wouldn't *you*?

Bob Shaw

Yeah, it is a kind of game!

Rodolfo

[pjm]

Why are you interested to catch any NH's signaling? Theirs are only useful for the John Hopkins Applied Physics Laboratory and nothing else.

Rodolfo

Hi,

Well I'm not really interested in the signalling, just to detect the carrier / tracking beacon. Demodulation isnt possible with small antennas, due to the low signal to noise ratio. But the technical challenge is making a receive system that can detect such small signals, thats all. I'm preparing a peltier cooled low noise amplifier which should add another 0.5dB SNR over my current setup.

cheers,

Paul
www.uhf-satcom.com

[mcaplinger]

There is some vague information on the JPL RAPWEB pages about long range forcasts of DSN resource useage, but nothing specific about start / end days and times.

Try going to the mid-range scheduling page; you can download the DSN schedule, and look for "NHPC" tracking passes.

[pjm]

Try going to the mid-range scheduling page; you can download the DSN schedule, and look for "NHPC" tracking passes.

Hi,

Yep I've looked there, the problem I have is that the medium range stuff is quite far in the future, and time is running out for opportunities to detect a signal, due to the rapidly increasing distance! The other factor that is unknown is the downlink frequency, so based on nasa's JPL horizons predictions for the space craft, we work out the doppler for every DSN channel then plod through looking for any signs of activity.

I have calculated that the signal should be stronger than that from the ESA Rosetta probe which is considerably further away, so I should be able to detect something.....

regards,

Paul
www.uhf-satcom.com

[mcaplinger]

the problem I have is that the medium range stuff is quite far in the future... The other factor that is unknown is the downlink frequency...

June is far in the future? OK, I can see how that might be true from your perspective.

http://www.cdscc.nasa.gov/Pages/pg03_trackingtoday.html has a partial daily schedule for Canberra. One could figure out the RA/Dec of NH and decide approximately when a pass could occur. I can't find the frequency allocation anywhere, and a detailed schedule would have to come via the project. If Alan Stern is reading this, he would be a good source.

[pjm]

June is far in the future? OK, I can see how that might be true from your perspective.

http://www.cdscc.nasa.gov/Pages/pg03_trackingtoday.html has a partial daily schedule for Canberra. One could figure out the RA/Dec of NH and decide approximately when a pass could occur. I can't find the frequency allocation anywhere, and a detailed schedule would have to come via the project. If Alan Stern is reading this, he would be a good source.

Hi, yes thanks for that link, i'd not seen that one before. Interesting that today DSS45 is tracking MRO and NHPC. I've copied the 3 mars orbiters today, and VEX this morning, but have been searching for NHPC for weeks with no trace. I think its on DSN channel 31 or 32. 8438.086418 or 8439.444446 in MHz.

OK so now its back to searching through the channels for an hour, until midnight here.

regards,

Paul
www.uhf-satcom.com

[pjm]

Hi all,

OK I can now cross NHPC off my list of space-craft to hear. Just managed to detect in FFT the tracking beacon from new horizons, using a 1.8m dish and home made receiver.

Brief write up at http://www.uhf-satcom.com/newhorizons/

cheers,

Paul.

[helvick]

OK I can now cross NHPC off my list of space-craft to hear. Just managed to detect in FFT the tracking beacon from new horizons, using a 1.8m dish and home made receiver.

Your score card is looking seriously impressive I must say. So how far away is your setup from being able to actually get data from such a signal?

[djellison]

Wow - given that VEX, MEX, MRO and MO were your previous targets, NH - beyond Mars, must be a new personal best - now you've got it once, hopefully you'll be able to really stretch the hardware and see how far out you can manage to still hear it!


Doug

[pjm]

Wow - given that VEX, MEX, MRO and MO were your previous targets, NH - beyond Mars, must be a new personal best - now you've got it once, hopefully you'll be able to really stretch the hardware and see how far out you can manage to still hear it!
Doug

Hi,

Well the above list of space craft are pretty close really. My current best DX with the little dish is the ESA rosetta (http://www.uhf-satcom.com/rosetta/) which at the time of reception was 242,198,000 miles away, so about 12dB further than NHPC. Also last night I managed to catch the Mars Global Surveyor, so I've now bagged all mars orbiters (that I can find info on that is)

There is a Mercury probe (messenger) that might be worth a listen, although its only got a small patch antenna for TX so may be pushing the limits of my system bigtime.

cheers,

Paul

[Bob Shaw]

Paul:

What would it take to extract data, particularly with global arrays of amateurs? I'm not talking about big images, just nice, compact science data...

Bob Shaw

[pjm]

Paul:

What would it take to extract data, particularly with global arrays of amateurs? I'm not talking about big images, just nice, compact science data...

Bob Shaw

Hi,

Well for a start, a bigger dish would be essential - it would be possible to phase several large antenna up, but it would need good frequency and time control at each site - i.e. gps locked oscillators, and phase coherant receivers. The major issue would be getting protocol information and the details relating to the modulation scheme of the space-craft. Detecting the signal is fine, but doing anything useful is difficult. I saw the very first MRO hi-res picture come from Mars, in the FFT you could clearly see the sidebands of data, but its just too weak to copy. Its probably possible for amateurs to do something, but it would need a fair amount of time / money to produce useable data.

regards,

Paul