1. Forum
  2. Usenet
  3. COMP.ARCH.EMBEDDED

  • modulating time markers

    From Hul Tytus@21:1/5 to All on Sat Jan 18 16:16:57 2025
    I'm looking into a time marker modulated onto a rf carrier that is
    simple and at the same time accurate. The marker on the low frequency
    signal carrying the US time reference which is said to invert the carrier
    to mark the time certainly sounds simple. The remarkable accuracy of the
    RTK GPS devices, actual inches are claimed, suggests a very accurate
    means of reading the time marker.
    Anyone know of a text that deals with such circuitry or perhaps a
    schematic of a gps reciever with enough detail to show how it's done?

    Hul

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From =?UTF-8?Q?Niocl=C3=A1i=C5=BF=C3=ADn@21:1/5 to All on Sat Jan 18 18:39:59 2025
    Dear Hul Tytus:

    Happy New Year!

    This is not as requested but might help to go to where you want to. In the
    Year that is called 2009 I reviewed "Fundamentals of Global Positioning
    System Receivers - A Software Approach" by James Bao-yen Tsui. It does not contain schematics. My copy is in storage so I cannot look it up to say
    what its index or table of contents say about encoding timing or radio
    signals. Sorry! Good luck!

    HTTPS://ACCU.org/bookreviews/2009/gloster_1826

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Paul Rubin@21:1/5 to Hul Tytus on Sat Jan 18 11:35:42 2025
    Hul Tytus <ht@panix.com> writes:
    Anyone know of a text that deals with such circuitry or perhaps a schematic of a gps reciever with enough detail to show how it's done?

    GPS is extremely complicated and studying it is probably not worth your
    while if you're only trying to modulate a time signal onto an RF
    carrier. For that, look at basic RF digital modulation techniques. Are
    you trying to get microsecond accuracy? Sub-millisecond? Sub-second?
    It gets easier at coarser levels. You stop having to account for speed
    of light delay between the transmitter and receiver, relativistic
    corrections because of the endpoints being in motion, etc.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)