Email Detail

HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/WU6WHIMMTPUBKC5G7WPXBXYWYH7ZTJCK/",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/",
    "message_id": "[email protected]",
    "message_id_hash": "WU6WHIMMTPUBKC5G7WPXBXYWYH7ZTJCK",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/WO5BBCGWJGYFFUSQUMHKSRAX3LNB7DKZ/",
    "sender": {
        "address": "orbitjet (a) hotmail.com",
        "mailman_id": null,
        "emails": null
    },
    "sender_name": "Rocky Jones",
    "subject": "[amsat-bb] Re: bbsat ideas...",
    "date": "2008-11-25T05:20:41Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/WO5BBCGWJGYFFUSQUMHKSRAX3LNB7DKZ/",
    "children": [
        "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/OEDSWDNDKBVIIPYC24STMK4OAVOQGGSQ/"
    ],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "\nWhat I think would be a good cubesat is just an SSTV transmitter...\n\nRobert  WB5MZO\n\n> From: [email protected]\n> To: [email protected]\n> Date: Mon, 24 Nov 2008 20:56:44 -0800\n> Subject: [amsat-bb]  bbsat ideas...\n> \n> \n> Nice thought provoking question, Joanne.  Here's an off-the-cuff  \n> idea.  I haven't tried to work out any of the numbers, it's just some  \n> idle musing.\n> \n> It has occurred to me that we are in the midst of a minor revolution  \n> in amateur radio (which will undoubtedly be followed by a more major  \n> revolution).   In the last 10 years, cheap computing and sound cards  \n> have caused a great deal of experimentation with \"sound card  \n> modes\" (the minor revolution), and will ultimately lead to the major  \n> revolution (widespread use of SDR).   We have a kind of flexibility  \n> that we couldn't think of even a few years ago, a flexibility that we  \n> gain from Moore's law.\n> \n> So here's an idea: let's do away with the need for Doppler correction  \n> entirely.  It's not like we don't have decent orbital elements for the  \n> satellites that we use.   It's not like our ground stations don't have  \n> accurate timing information available to them.   Even if we didn't, we  \n> could still output a (coded?) carrier that our\n> soundcard modem could lock onto, and then transmit relative to that  \n> frequency.\n> \n> Given the relatively limited amount of power that we are likely to  \n> have in a cubesat, the question then becomes what is the best way to  \n> use that power?   It seems unlikely that any kind of linear  \n> transponder will allow more than just a couple of users meaningful  \n> access.  I'd suggest it might make more sense to do some kind of  \n> digital transponder.   I'm imagining a satellite which monitors a  \n> chunk of spectrum roughly the size of a current SSB signal, say  \n> 2.4khz.   Imagine that space was divided into (say) 10 channels, each  \n> 240hz wide.  We could easily fit a PSK63 signal (or a similar FSK  \n> signal, pick your poison) in that space.  You could use a bent pipe  \n> crossband transponder, or potentially do a simplex repeater (say the  \n> sat listens for 10 seconds, then re-echoes for 10 seconds) on the same  \n> uplink frequency.   If you are a downlink station, you know what you  \n> sent, and can tell if your signal got collided with, and if so, you  \n> can switch to another of the 10 slots.    In the mean time, you can  \n> easily monitor all of the other slots as well, and try to pick an  \n> unoccupied one.  While it might be difficult for a power-efficient  \n> controller to actually _decode_ each of the 10 channels, it probably  \n> could determine which channels are busy itself by monitoring power in  \n> each of the channels.   Maybe we can fill\n> unused slots with telemetry?  Or can we actually get enough DSP power  \n> into a cubesat to decode 10 channels of PSK (or some similar  \n> protocol), which would help a lot (the bird only transmits stuff, and  \n> what it transmits is free from noise/errors).    If not 10 channels,  \n> then how 'bout 5?  2?  Even one?  Then, we basically have a simple  \n> digipeater, which can obviously be done, given the existance of 1200  \n> baud modems based upon PIC microcontrollers.\n> \n> Just some lunacy...\n> \n> \tMark KF6KYI\n>   \n> _______________________________________________\n> Sent via [email protected]. Opinions expressed are those of the author.\n> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n\n_________________________________________________________________\nColor coding for safety: Windows Live Hotmail alerts you to suspicious email.\nhttp://windowslive.com/Explore/Hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_safety_112008 ",
    "attachments": []
}